vaccination

Oral treatment may not be far off for head and neck cancer patients

Source: app.secure.griffith.edu.au
Author: staff, Griffith University

A highly promising approach to treating HPV-driven head and neck cancer is on the way, and it could be in the shape of a simple oral medication. This is according to new breakthrough research led by Griffith University, which has conducted trials showing that the drug, Alisertib, tested in trials to treat other cancers such as lung and kidney, can also successfully destroy the cancer cells associated with head and neck cancer.

Human Papilloma Virus (HPV) is the main culprit in head, neck and oral cancers. The virus is thought to be the most common sexually transmitted infection (STI) in the world, and most people are infected with HPV at some time in their lives.

The latest trials – which have taken place over the past three years at Griffith’s Gold Coast campus – have shown a particular enzyme inhibitor in the drug, has the ability to prevent proliferation of HPV cancer cells in advanced head and neck cancers.

A 100 per cent success rate
Led by Professor Nigel McMillan, program director from Griffith’s Menzies Health Institute Queensland, the trials have shown a 100 per cent success rate in the drug eradicating the cancerous tumours in animals.

“Head and neck cancers can unfortunately be very difficult to treat, just by the very nature of where they are located in and around the throat, tongue and mouth,” says Professor McMillan.

“This part of the body contains some delicate areas such as the vocal chords and areas relating to speech, taste, smell, saliva etc, therefore there can be some significant side effects with the current treatment options.

“Quality of life is a major consideration in this patient group and therefore a simple oral treatment regimen will have massive benefit over other treatments in terms of reducing some quite drastic side effects.”

In Australia, there are over 5000 new cases of head and neck cancer each year. First line treatments include radiation and surgery (increasingly of the robotic type), followed by chemotherapy, however survival rates of around 70 per cent have remained unchanged for the past 35 years.

Half of all head and neck cancers are known to be caused by the HPV virus, with four times as many men (784) as women (250) estimated to have already died from the disease in Australia during 2018.

In the United States, there are now more cases of head and neck cancer than there are cervical cancer, a disease which is now set to become much more rare in Australia due to the introduction a decade ago of the world-leading national (HPV) vaccination program for schoolchildren.

Professor McMillan says the next step in the research is for the drug to be extended to human trials at the Gold Coast with patients for whom other treatments have so far proved unsuccessful.

October, 2018|Oral Cancer News|

FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old

The U.S. Food and Drug Administration today approved a supplemental application for Gardasil 9 (Human Papillomavirus (HPV) 9-valent Vaccine, Recombinant) expanding the approved use of the vaccine to include women and men aged 27 through 45 years. Gardasil 9 prevents certain cancers and diseases caused by the nine HPV types covered by the vaccine.

“Today’s approval represents an important opportunity to help prevent HPV-related diseases and cancers in a broader age range,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research. ”The Centers for Disease Control and Prevention has stated that HPV vaccination prior to becoming infected with the HPV types covered by the vaccine has the potential to prevent more than 90 percent of these cancers, or 31,200 cases every year, from ever developing.”

According to the CDC, every year about 14 million Americans become infected with HPV; about 12,000 women are diagnosed with and about 4,000 women die from cervical cancer caused by certain HPV viruses. Additionally, HPV viruses are associated with several other forms of cancer affecting men and women.

Gardasil, a vaccine approved by the FDA in 2006 to prevent certain cancers and diseases caused by four HPV types, is no longer distributed in the U.S. In 2014, the FDA approved Gardasil 9, which covers the same four HPV types as Gardasil, as well as an additional five HPV types. Gardasil 9 was approved for use in males and females aged 9 through 26 years.

The effectiveness of Gardasil is relevant to Gardasil 9 since the vaccines are manufactured similarly and cover four of the same HPV types. In a study in approximately 3,200 women 27 through 45 years of age, followed for an average of 3.5 years, Gardasil was 88 percent effective in the prevention of a combined endpoint of persistent infection, genital warts, vulvar and vaginal precancerous lesions, cervical precancerous lesions, and cervical cancer related to HPV types covered by the vaccine. The FDA’s approval of Gardasil 9 in women 27 through 45 years of age is based on these results and new data on long term follow-up from this study.

Effectiveness of Gardasil 9 in men 27 through 45 years of age is inferred from the data described above in women 27 through 45 years of age, as well as efficacy data from Gardasil in younger men (16 through 26 years of age) and immunogenicity data from a clinical trial in which 150 men, 27 through 45 years of age, received a 3-dose regimen of Gardasil over 6 months.

The safety of Gardasil 9 was evaluated in about a total of 13,000 males and females. The most commonly reported adverse reactions were injection site pain, swelling, redness and headaches.

The FDA granted the Gardasil 9 application priority review status. This program facilitates and expedites the review of medical products that address a serious or life-threatening condition.

The FDA granted approval of this supplement to the Gardasil 9 Biologics License Application to Merck, Sharp & Dohme Corp. a subsidiary of Merck & Co., Inc.

The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.

October, 2018|Oral Cancer News|

HPV-related cancer rates outpace vaccinations

Source: www.ctpost.com
Author: Cara Rosner, Conn. Health

Cancers linked to the human papillomavirus, commonly called HPV, rose dramatically in a 15-year period, even as the rates of young people being vaccinated climbed, the Centers for Disease Control and Prevention reported.

The 43,371 new cases of HPV-associated cancers reported nationwide in 2015 marked a 44 percent jump from the 30,115 cases reported in 1999, according to a CDC analysis. HPV vaccination rates have improved over the years, but not fast enough to stem the rise in cancers, the CDC said.

Oropharyngeal, or throat, cancer was the most common HPV-associated cancer in 2015, accounting for 15,479 cases among males and 3,438 among females. HPV infects about 14 million people each year. Between 1999 and 2015 rates of throat and vulvar cancer increased, vaginal and cervical cancer rates declined, and penile cancer rates were stable, according to the CDC.

“The (overall rise) seems to be mostly driven by oropharyngeal cancers,” said Dr. Sangini Sheth, assistant professor of obstetrics, gynecology and reproductive sciences at Yale School of Medicine.

“Vaccination is key to preventing those cancers,” said Sheth, who also is an associate medical director and director of colposcopy and cervical dysplasia at Yale New Haven Hospital’s Women’s Center. “Oropharyngeal cancer is most common in men, and HPV vaccination rates, while they are rising in the U.S. and Connecticut, became routine for boys later (than girls). And the rate of vaccinations among boys has definitely lagged that of girls. Hopefully, we will see vaccinating our boys have an impact on oropharyngeal cancer, but that’s going to take time.”

The push to vaccinate adolescents against HPV is a relatively recent development. The vaccination was included in the routine immunization program for females in 2006 and for males in 2011, according to the CDC.

At one time, the HPV-vaccine was viewed largely to prevent sexually transmitted diseases, and some parents “resented” it and thought it was unnecessary for their children, according to Dr. Richard Brauer, section head of otolaryngology at Greenwich Hospital. Now it’s marketed as a cancer vaccine and parents have become more receptive, said Brauer, who also has a private practice, Associates of Otolaryngology, in Greenwich.

In 2017, 65.5 percent of adolescents aged 13 to 17 nationwide had at least one dose of the HPV vaccine, up 5.1 percentage points from 2016, according to CDC data released in August.

In Connecticut, 75.4 percent of girls aged 13 to 17 had one dose of the vaccine, 67.1 percent had two doses and 58.4 received three doses. Among males, 67.3 percent received one dose, 58.8 percent got two and 37.8 percent got three, the 2017 data show. But even amid overall gains, hurdles remain. Gender disparity persists, and many teens received the first vaccine dose but failed to get necessary subsequent doses.

Children who are 11 or 12 years old should get two shots of HPV vaccine six to 12 months apart, according to the CDC. Adolescents who get their shots less than five months apart need a third dose of the vaccine, as do all children older than 14. Three doses also are recommended for people ages nine to 26 who have certain immunocompromised conditions.

“It falls on the parent” whether children get vaccinated, said Dr. Bradford Whitcomb, chief of gynecologic oncology at UConn Health. “People associate HPV with female stuff. It needs to be pushed that we’re not just preventing female cancers.”

While it’s encouraging that vaccination rates are climbing, “we just may not see the benefit of that for years to come,” Whitcomb said. “It’s going to take a longer time, especially with the development of cancer, to see the effect. After the HPV infection, it can take years for a cancer to develop.”

Many people exposed to HPV will never get cancer, doctors said. The most common HPV-associated cancer among women is cervical cancer. Data show rates of that cancer are falling, but there are racial disparities.

Between 2011 and 2015, Hispanic women had the highest incidence rates of cervical cancer at 8.9 percent, according to an analysis by the Kaiser Family Foundation. That compares with 8.4 percent among black women, 7.4 percent among white women and 6.1 percent among Asian and Pacific Islander women.

Cervical cancer mortality rates also showed racial disparities during that time. Black women had the highest mortality rate at 3.7 percent, compared with 2.6 percent among Hispanics, 2.2 percent among whites and 1.8 percent among Asians and Pacific Islanders, data show.

It is crucial for doctors to talk to young patients and their parents about the HPV vaccine, even if it spurs conversations parents may feel awkward having, Sheth said.

“Clinicians need to feel comfortable normalizing the HPV vaccine and really present the HPV vaccine as a cancer prevention tool,” she said.

Note:
This story was reported under a partnership with the Connecticut Health I-Team, a nonprofit news organization dedicated to health reporting. (c-hit.org)

September, 2018|Oral Cancer News|

Head and neck cancer: An overview of head and neck cancer

Source: www.curetoday.com
Author: staff

Meryl Kaufman, M.Ed., CCC-SLP, BRS-S, and Itzhak Brook, M.D., M.Sc., board members of the Head and Neck Cancer Alliance, discuss the prevalence of cancers of the head and neck, emphasizing the potential risk factors and importance of prevention.

Transcript:
Meryl Kaufman, M.Ed., CCC-SLP, BRS-S: Welcome to this CURE Connections® program titled “Head and Neck Cancer: Through the Eyes of a Patient.” I’m Meryl Kaufman, a certified speech-language pathologist and founder of Georgia Speech and Swallowing LLC. I am joined today by Dr. Itzhak Brook, a professor of pediatrics and medicine at Georgetown University School of Medicine, who was diagnosed with throat cancer in 2006. Together we will discuss the prevalence of head and neck cancer, what unique challenges patients may face and how one can adjust to life after receiving treatment for their disease. Dr. Brook and I also serve as board members on the Head and Cancer Alliance.

Dr. Brook, let’s talk about head and neck cancer in general. What’s the difference between head and neck cancer associated with the traditional risk factors, such as smoking and drinking, and HPV-related head and neck cancers?

Itzhak Brook, M.D., M.Sc.: The traditional head and neck cancer is related to smoking and alcohol consumption. It’s usually associated with a high rate of laryngeal cancer. And HPV-related cancer is a relatively new arrival on the scene of head and neck cancer, and it’s associated with a condition of infection by a venereal disease. The virus HPV is usually associated with a posterior tongue cancer or an oropharyngeal cancer.

Meryl Kaufman, M.Ed., CCC-SLP, BRS-S: Exactly, yes. So the HPV viruses typically in the oropharynx, the tonsil and the tongue basis are certainly rising in incidence as compared with the traditional head and neck cancers, which are decreasing in incidence. In fact, it’s anticipated that in the year 2020, the HPV-related oropharyngeal cancers are going to surpass HPV-related cervical cancers, which are typically what you think of with the HPV virus. So that is a new patient population, but the good news is that the survival rates are better for the HPV-related head and neck cancers versus the non-HPV-related cancers. Can you speak a little bit about the incidence of the two?

Itzhak Brook, M.D., M.Sc.: The incidence of head and neck cancer is not as high as others like colon cancer, breast cancer in women or lung cancer, but it’s around the ninth or 10th cause of cancer in the world in this country. In countries where there is smoking and alcohol consumption, it’s a higher rate. HPV is usually happening in younger people, in the late 30s or early 40s. And fortunately, we hope that it could be prevented by vaccination. Although it’s approved that it can, it’s not yet available because the incubation period for the cancer, as you may call it, takes 20, 30 years, so we don’t really know. Fortunately, even though HPV is very common, the occurrence of HPV-related cancer is very, very rare.

Meryl Kaufman, M.Ed., CCC-SLP, BRS-S: Correct. In terms of the vaccination for the HPV virus, I agree, the proof certainly isn’t definitively out there yet, but the vaccine protects against the strain of virus that ultimately can lead to head and neck cancer. So the thought is that by preventing the contraction of the virus, hopefully we can also prevent these head and neck cancers, which is why the American Academy of Pediatrics and the CDC (Centers for Disease Control and Prevention) recommend that children between the ages of 11 and 12, female and males, are vaccinated prior to sexual debut in the hopes of preventing these cancers down the road, certainly. So yes, head and neck cancer does account for about 6 percent of all cancers worldwide, with about 500,000 cases worldwide. And in the United States, we anticipate about 65,000 a year, I believe, and they do occur more frequently in men, almost twice as often in men than in women and typically in people over the age of 50 in the traditional head and neck cancers. But certainly, there is a change in that with the introduction of the HPV-related cancers. Can you talk a little bit about prevention in terms of things that we can do to prevent the risky behaviors?

Itzhak Brook, M.D., M.Sc.: Of course, with the traditional cancers, it can be prevented by not smoking or drinking alcohol in high quantities. But there’s the behavioral changes that men and women can change that can reduce the risk of acquiring it. It’s a sexually transmitted disease. Oral sex has been the No. 1 cause, so you think of condoms or men using them also when having oral sex may prevent it.

September, 2018|Oral Cancer News|

Doctors push HPV vaccine, Merck asks FDA to expand Gardasil 9 age range

Source: www.drugwatch.com
Author: Michelle Llamas, Emily Miller (editor)

Doctors, national cancer organizations and 70 nationally recognized cancer centers banded together in June to increase HPV vaccinations and improve cervical cancer screening. But they’re not the only ones pushing for more vaccinations.

HPV vaccine maker Merck requested the FDA expand the recommended age range for Gardasil 9. Gardasil 9 is currently the only HPV vaccination available in the U.S.

Nearly 80 million Americans get HPV infections each year. Of those people, about 32,500 get HPV-related cancers, according to the CDC.

Studies show the HPV vaccine is effective in protecting against the human papilloma virus. The virus can lead to several cancers. These include cervical, vaginal, vulvar, anal, penile or throat cancers.

HPV vaccination rates in the U.S. remain low. Doctors and cancer centers say low vaccination rates are a public health threat.

“HPV vaccination is cancer prevention,” Dr. Deanna Kepka, assistant professor in the University of Utah’s College of Nursing, said in a statement. “It is our best defense in stopping HPV infection in our youth and preventing HPV-related cancers in our communities.”

Right now, the vaccination rate among teens ages 13 to 17 is 60 percent. Doctors are pushing for an 80 percent HPV vaccination rate in pre-teen boys and girls.

“[Vaccination] combined with continued screening and treatment for cervical pre-cancers … could see the elimination of cervical cancer in the U.S. within 40 years,” Dr. Richard Wender, chief cancer control officer for the American Cancer Society, said in a news release. “No cancer has been eliminated yet, but we believe if these conditions are met, the elimination of cervical cancer is a very real possibility.”

Gardasil 9 requires two to three doses to be complete. Only 43 percent of teens get all required doses.

Studies show the vaccine is safe for most people. The most common side effects are headache, nausea, vomiting and fever.

But, the HPV vaccine may cause rare but serious side effects. The FDA’s Vaccine Adverse Event Reporting System has reports of autoimmune diseases, deaths and premature ovarian failure linked to the vaccine.

The National Vaccine Injury Compensation Program (VICP) has paid out millions to a few people who said the vaccine injured them. Since 2006, VICP has paid out or settled 126 HPV claims and dismissed 157.

Current campaigns urge pre-teens and teens to get the HPV vaccine. Merck wants more adults to get the vaccine, too.

At the beginning of June, the FDA accepted Merck’s application to expand the age range for Gardasil 9. The agency granted it priority review. The FDA originally approved Gardasil 9 for people ages 9 to 26. But Merck wants that age range expanded to include adults ages 27 to 45.

“Women and men ages 27 to 45 continue to be at risk for acquiring HPV, which can lead to cervical cancer and certain other HPV-related cancers and diseases,” Dr. Alain Luxembourg, Merck Laboratories’ director of clinical research, said in a statement.

HPV is a group of about 150 related viruses. Gardasil 9 protects against nine strains. The FDA hopes to reach a decision on the application by Oct. 2, 2018.

Should kids be required to get the HPV vaccine?

Source: www.forbes.com
Author: Bruce Y. Lee

If a bill recently introduced in Florida passes, the human papillomavirus (HPV) vaccine would be mandatory for adolescents attending public school in the state. Currently, the vaccine is mandatory for boys and girls in Rhode Island and just girls in Virgina and Washington, DC. (AP Photo/John Amis, File)

Florida isn’t kidding about low human papillomavirus (HPV) vaccination rates. If you are a kid enrolled in a Florida public school, come July 1, 2018, you may be required to get the HPV vaccine. That is if you are old enough and if a bill now being debated in the Florida state legislature ends up passing.

If it gets through, Senate Bill 1558 would then become known as the “Women’s Cancer Prevention Act”, which is a much easier name to remember and also reflects some major benefits of the HPV vaccine. As the National Cancer Institute explains, HPV vaccine can help prevent not only cervical cancer but also many vaginal and vulvar cancers. In fact, two types of HPV (16 and 18) cause around 70% of cervical cancers. But just because you don’t have a vagina, cervix, and vulva doesn’t mean that you are in the clear. HPV is responsible for about 95% of anal cancers, 70% of oropharyngeal (the middle part of the throat) cancers, and 35% of penile cancers. Thus, the “Women’s Cancer Prevention Act” is really a “Cancer Prevention Act.”

Regardless, Florida State Senator José Javier Rodríguez (D-Miami) filed this bill on January 4 in an effort to boost Florida’s not so great HPV vaccination rates. According to the just-released Blue Cross Blue Shield Association (BCBSA) Health of America Report, only 29.0% of adolescents in Florida got the first dose of the HPV vaccine and only 7.3% got all doses in the series as of 2016. Those numbers are lower than the national average (34.4% got the first dose) but not the worst in the country.

New Jersey was the worst (not in general as a state but in terms of HPV vaccination rates). Based on the BCBSA report, as of 2016, only 20.6% of adolescents in New Jersey had gotten the HPV vaccine by age 13 and only 3.4% had completed the series. The Health of America report was the result of an analysis of medical claims data from 2010 through 2016 of over 1.3 million BCBSA commercially-insured adolescents across the country. The analysis considered vaccination to be on time if performed between the adolescent’s 10th and 13th birthdays, corresponding with the Centers for Disease Control and Prevention (CDC) recommendations of 11 to 12 year olds getting the vaccine.

Of course, the analysis did not include all adolescents in America. As BCBSA Chief Medical Officer Trent Haywood, MD, JD, explained, “the analysis represented the commercial population and didn’t include Medicaid populations. Also, to be included in the analysis, an adolescent had to be continuously enrolled with BCBS.” But studying such a large population is a pretty good shot at trying to figure what’s going on with shots and adolescents nationwide.

The report also showed that girls were better than boys (again, not in general, but in terms of HPV vaccination rates). In 2016, 37% of girls had received the first dose of the HPV vaccines by age 13 compared to 32%.

The best state of the bunch? Rhode Island with 57% of adolescents having received their first dose by age 13. Not coincidentally Rhode Island is the only state requiring HPV vaccine for both male and female students, starting with the first dose by 7th grade. Virginia and Washington, DC, have requirements just for females.

The good news is that nationwide vaccination rates steadily rose from 22% getting the first dose by age 13 in 2013 to 34% in 2016. But why are vaccination rates still well below 50% in most states? A BCBSA-commissioned survey of over 700 parents of adolescents aged 10-13 revealed the following top three reasons for parents not vaccinating their child against HPV:

  • Being concerned about adverse side effects (59.4%)
  • Not thinking their child is at risk (23.6%)
  • Not knowing their child needed an HPV vaccination (15.7%)

Is requiring the HPV vaccine the solution? One argument against making the HPV vaccine mandatory is that people should be allowed freedom of choice. When Rhode Island first introduced its requirement, protests resulted various groups such as parents, a 2,400-member plus Facebook group, and the American Civil Liberties Union.

However, the counter-argument is that freedom of choice does not always hold when in the words of Spock, “the needs of the many outweigh the needs of the few.” You aren’t free to run up and down the aisle of an airplane naked and screaming because the needs of other on the plane outweigh the needs of you. Similarly, the HPV vaccine could help slow and even stop the transmission of HPV throughout the population, which can result in cancers that not only affect the cancer victims but also society by adding to health care costs.

Here is a Today show segment on the HPV vaccine:

Also, when a child doesn’t get vaccinated, it is usually because of the parent’s choice and not the child’s. Could making the vaccine mandatory in fact be protecting the child?

Another argument used by some is that the HPV vaccine has adverse effects. There are websites claiming that HPV vaccine can cause “crippling side effects” and “death.” But many of these scarier claims are not supported by rigorous scientific evidence. (Note: there are also websites that say that the Earth is flat, Elvis was an alien, and the government controls the weather). While nothing is completely safe (e.g., even a chocolate chip cookie in the right situation could do some real damage) and all vaccines do have their risks, the risks of the HPV vaccine are comparatively very low and far outweighed by the potential benefits as indicated by the CDC.

As I wrote before for Forbes, some have argued that the HPV vaccine is a “gateway to sex” and thus making it mandatory would increase the number of teenagers having sex and encourage promiscuity. However, this goes counter to the recent trend of teenagers delaying when they first have sex and suggests that teenagers would not have sex if it weren’t for that darn HPV vaccine. A related argument is that the HPV vaccine would give teens a false sense of security that they are protected against all sexually transmitted infections, leading them to not practice safe sex. However, raising awareness of what the HPV vaccine actually does could help overcome this concern.

All of this does not necessarily mean that making HPV vaccination mandatory is the solution. However, what then is the solution to a majority of adolescents still not getting vaccinated (at least by age 13 and when sexual activity for some begin)? As Haywood described, this is a situation in which many are “not taking full advantage of preventive measures. A big issue is lack of awareness of the HPV vaccine and its benefits.” HPV vaccine awareness campaigns may help push up vaccination rates, but by how much?

The wonderfully straight-forward and transparent world of politics will help determine whether Senate Bill 1558 becomes a law in Florida. A similar bill failed to pass in 2011. But things have changed since 2011, in good ways and bad.

February, 2018|Oral Cancer News|

The Unforgiving Math That Stops Epidemics

Author: Tara C. Smith
Source: www.quantamagazine.org
Date: October 26, 2017

As the annual flu season approaches, medical professionals are again encouraging people to get flu shots. Perhaps you are among those who rationalize skipping the shot on the grounds that “I never get the flu” or “if I get sick, I get sick” or “I’m healthy, so I’ll get over it.” What you might not realize is that these vaccination campaigns for flu and other diseases are about much more than your health. They’re about achieving a collective resistance to disease that goes beyond individual well-being — and that is governed by mathematical principles unforgiving of unwise individual choices.

When talking about vaccination and disease control, health authorities often invoke “herd immunity.” This term refers to the level of immunity in a population that’s needed to prevent an outbreak from happening. Low levels of herd immunity are often associated with epidemics, such as the measles outbreak in 2014-2015 that was traced to exposures at Disneyland in California. A study investigating cases from that outbreak demonstrated that measles vaccination rates in the exposed population may have been as low as 50 percent. This number was far below the threshold needed for herd immunity to measles, and it put the population at risk of disease.

The necessary level of immunity in the population isn’t the same for every disease. For measles, a very high level of immunity needs to be maintained to prevent its transmission because the measles virus is possibly the most contagious known organism. If people infected with measles enter a population with no existing immunity to it, they will on average each infect 12 to 18 others. Each of those infections will in turn cause 12 to 18 more, and so on until the number of individuals who are susceptible to the virus but haven’t caught it yet is down to almost zero. The number of people infected by each contagious individual is known as the “basic reproduction number” of a particular microbe (abbreviated R0), and it varies widely among germs. The calculated R0 of the West African Ebola outbreak was found to be around 2 in a 2014 publication, similar to the R0 computed for the 1918 influenza pandemic based on historical data.

Quantized Columns

If the Ebola virus’s R0 sounds surprisingly low to you, that’s probably because you have been misled by the often hysterical reporting about the disease. The reality is that the virus is highly infectious only in the late stages of the disease, when people are extremely ill with it. The ones most likely to be infected by an Ebola patient are caregivers, doctors, nurses and burial workers — because they are the ones most likely to be present when the patients are “hottest” and most likely to transmit the disease. The scenario of an infectious Ebola patient boarding an aircraft and passing on the disease to other passengers is extremely unlikely because an infectious patient would be too sick to fly. In fact, we know of cases of travelers who were incubating Ebola virus while flying, and they produced no secondary cases during those flights.

Note that the R0 isn’t related to how severe an infection is, but to how efficiently it spreads. Ebola killed about 40 percent of those infected in West Africa, while the 1918 influenza epidemic had a case-fatality rate of about 2.5 percent. In contrast, polio and smallpox historically spread to about 5 to 7 people each, which puts them in the same range as the modern-day HIV virus and pertussis (the bacterium that causes whooping cough).

Determining the R0 of a particular microbe is a matter of more than academic interest. If you know how many secondary cases to expect from each infected person, you can figure out the level of herd immunity needed in the population to keep the microbe from spreading. This is calculated by taking the reciprocal of R0 and subtracting it from 1. For measles, with an R0 of 12 to 18, you need somewhere between 92 percent (1 – 1/12) and 95 percent (1 – 1/18) of the population to have effective immunity to keep the virus from spreading. For flu, it’s much lower — only around 50 percent. And yet we rarely attain even that level of immunity with vaccination.

Once we understand the concept of R0, so much about patterns of infectious disease makes sense. It explains, for example, why there are childhood diseases — infections that people usually encounter when young, and against which they often acquire lifelong immunity after the infections resolve. These infections include measles, mumps, rubella and (prior to its eradication) smallpox — all of which periodically swept through urban populations in the centuries prior to vaccination, usually affecting children.

Do these viruses have some unusual affinity for children? Before vaccination, did they just go away after each outbreak and only return to cities at approximately five- to 10-year intervals? Not usually. After a large outbreak, viruses linger in the population, but the level of herd immunity is high because most susceptible individuals have been infected and (if they survived) developed immunity. Consequently, the viruses spread slowly: In practice, their R0 is just slightly above 1. This is known as the “effective reproduction number” — the rate at which the microbe is actually transmitted in a population that includes both susceptible and non-susceptible individuals (in other words, a population where some immunity already exists). Meanwhile, new susceptible children are born into the population. Within a few years, the population of young children who have never been exposed to the disease dilutes the herd immunity in the population to a level below what’s needed to keep outbreaks from occurring. The virus can then spread more rapidly, resulting in another epidemic.

An understanding of the basic reproduction number also explains why diseases spread so rapidly in new populations: Because those hosts lack any immunity to the infection, the microbe can achieve its maximum R0. This is why diseases from invading Europeans spread so rapidly and widely among indigenous populations in the Americas and Hawaii during their first encounters. Having never been exposed to these microbes before, the non-European populations had no immunity to slow their spread.

If we further understand what constellation of factors contributes to an infection’s R0, we can begin to develop interventions to interrupt the transmission. One aspect of the R0 is the average number and frequency of contacts that an infected individual has with others susceptible to the infection. Outbreaks happen more frequently in large urban areas because individuals living in crowded cities have more opportunities to spread the infection: They are simply in contact with more people and have a higher likelihood of encountering someone who lacks immunity. To break this chain of transmission during an epidemic, health authorities can use interventions such as isolation (keeping infected individuals away from others) or even quarantine (keeping individuals who have been exposed to infectious individuals — but are not yet sick themselves — away from others).

Other factors that can affect the R0 involve both the host and the microbe. When an infected person has contact with someone who is susceptible, what is the likelihood that the microbe will be transmitted? Frequently, hosts can reduce the probability of transmission through their behaviors: by covering coughs or sneezes for diseases transmitted through the air, by washing their contaminated hands frequently, and by using condoms to contain the spread of sexually transmitted diseases.

These behavioral changes are important, but we know they’re far from perfect and not particularly efficient in the overall scheme of things. Take hand-washing, for example. We’ve known of its importance in preventing the spread of disease for 150 years. Yet studies have shown that hand-washing compliance even by health care professionals is astoundingly low — less than half of doctors and nurses wash their hands when they’re supposed to while caring for patients. It’s exceedingly difficult to get people to change their behavior, which is why public health campaigns built around convincing people to behave differently can sometimes be less effective than vaccination campaigns.

How long a person can actively spread the infection is another factor in the R0. Most infections can be transmitted for only a few days or weeks. Adults with influenza can spread the virus for about a week, for example. Some microbes can linger in the body and be transmitted for months or years. HIV is most infectious in the early stages when concentrations of the virus in the blood are very high, but even after those levels subside, the virus can be transmitted to new partners for many years. Interventions such as drug treatments can decrease the transmissibility of some of these organisms.

The microbes’ properties are also important. While hosts can purposely protect themselves, microbes don’t choose their traits. But over time, evolution can shape them in a manner that increases their chances of transmission, such as by enabling measles to linger longer in the air and allowing smallpox to survive longer in the environment.

By bringing together all these variables (size and dynamics of the host population, levels of immunity in the population, presence of interventions, microbial properties, and more), we can map and predict the spread of infections in a population using mathematical models. Sometimes these models can overestimate the spread of infection, as was the case with the models for the Ebola outbreak in 2014. One model predicted up to 1.4 million cases of Ebola by January 2015; in reality, the outbreak ended in 2016 with only 28,616 cases. On the other hand, models used to predict the transmission of cholera during an outbreak in Yemen have been more accurate.

The difference between the two? By the time the Ebola model was published, interventions to help control the outbreak were already under way. Campaigns had begun to raise awareness of how the virus was transmitted, and international aid had arrived, bringing in money, personnel and supplies to contain the epidemic. These interventions decreased the Ebola virus R0 primarily by isolating the infected and instituting safe burial practices, which reduced the number of susceptible contacts each case had. Shipments of gowns, gloves and soap that health care workers could use to protect themselves while treating patients reduced the chance that the virus would be transmitted. Eventually, those changes meant that the effective R0 fell below 1 — and the epidemic ended. (Unfortunately, comparable levels of aid and interventions to stop cholera in Yemen have not been forthcoming.)

Catch-up vaccinations and the use of isolation and quarantine also likely helped to end the Disneyland measles epidemic, as well as a slightly earlier measles epidemic in Ohio. Knowing the factors that contribute to these outbreaks can aid us in stopping epidemics in their early stages. But to prevent them from happening in the first place, a population with a high level of immunity is, mathematically, our best bet for keeping disease at bay.

November, 2017|Oral Cancer News|

7 million American men carry cancer-causing HPV virus

Source: www.nytimes.com
Author: Nicholas Bakalar

The incidence of mouth and throat cancers caused by the human papilloma virus in men has now surpassed the incidence of HPV-related cervical cancers in women, researchers report.

The study, in the Annals of Internal Medicine, found that 11 million men and 3.2 million women in the United States had oral HPV infections. Among them, 7 million men and 1.4 million women had strains that can cause cancers of the throat, tongue and other areas of the head and neck.

The risk of infection was higher for smokers, for people who have had multiple sex partners, and for men who have sex with men. Frequent oral sex also increased the risk. The rate was higher among men who also had genital HPV. (Almost half of men aged 18 to 60 have a genital HPV infection, according to the Centers for Disease Control and Prevention.)

Neither age nor income made a difference in high-risk oral infection rates, but rates among non-Hispanic blacks were higher than other races and ethnicities.

HPV vaccination is recommended starting at age 11 or 12 and is effective, said the senior author, Ashish A. Deshmukh, an assistant professor at the University of Florida, and “it’s crucial that parents vaccinate boys as well as girls.”

The lead author, Kalyani Sonawane, also at the University of Florida, said that behavioral change is important, too, particularly smoking cessation. “The difference in oral HPV infection between smokers and nonsmokers is staggering,” she said.

October, 2017|Oral Cancer News|

Should women older than 18 get the HPV vaccine?

Source: www.washingtonpost.com
Author: Erin Blakemore

About half of American teenagers have been vaccinated against the human papillomavirus (HPV), the most common sexually transmitted infection in the United States. Should adult women follow suit?

Yes, says Lauri Markowitz, a Centers for Disease Control and Prevention medical epidemiologist who has worked with the advisory committee that makes national vaccination recommendations. “Women 18 to 26 should be vaccinated.”

There’s good reason to follow that recommendation. According to the American Cancer Society, about 12,820 new cases of cervical cancer will be diagnosed in U.S. women this year and more than 4,000 will die of the disease. HPV is thought to be responsible for more than 90 percent of all cervical and anal cancers in men and women. The virus also causes vaginal, vulvar and throat cancers and genital warts.

Although the majority of HPV infections do not cause cancer — most people with an infection never show any symptoms, and infections usually go away on their own — some strains are particularly dangerous. Gardasil 9, the newest HPV vaccine approved by the Food and Drug Administration, protects against nine such strains and, researchers say, may be able to prevent up to 90 percent of cervical cancers. (Older vaccines protect against fewer strains of HPV.)

However, confusion about the way HPV vaccines protect against infection can deter some women. Gardasil 9 is approved for women up to age 26. Like other vaccines, it spurs the body’s immune system to defend itself against a virus. The FDA and CDC say the HPV vaccines are safe and extremely effective: HPV rates in women ages 14 to 19 years fell 64 percent within six years of the vaccine’s introduction in the United States in the mid-2000s and 34 percent in women ages 20 to 24.

The vaccines are most effective if administered before a woman becomes sexually active. The longer a woman has been sexually active and the more partners she has had, the more opportunities she has had to become infected with an HPV strain that overlaps with the vaccine. If she is vaccinated at an older age, the vaccine may be less effective in lowering her cancer risk, Markowitz says. The vaccine can’t clear any HPV that has taken hold; it can only prevent future infection. So essentially if you already have been exposed to one of the strains it protects against, it will be useless against that strain.

That doesn’t mean it’s useless to get vaccinated if you’re older than the recommended age of 11 or 12, Markowitz says. “Your chances of being protected are decreasing, but you will still have some protection,” she says. Although the likelihood that a sexually active woman has been infected with one of the strains the vaccine protects against increases as a woman has more partners, those who didn’t receive the vaccine at the recommended age are still urged to get vaccinated to increase the odds of protection.

Some insurance does not cover the vaccine for those older than 18 — the shots can be costly, though the manufacturer may provide assistance — but it really varies across the board.

October, 2017|Oral Cancer News|

HPV and mouth cancer

Source: www.hippocraticpost.com
Author: Thea Jourdan

hpv

Mouth cancer kills nearly 2000 people in the UK each year. The Human Papilloma Virus (HPV) of which there are over 100 different types, is more commonly associated with cervical cancer and genital warts, but it can also cause oral cancer, particularly of the back of the tongue and tonsils. The virus incorporates itself into the cell’s DNA and causes the cell to multiply out of control, leading to cancer.

In Britain, the number of mouth and throat cancers have increased by 40 per cent in just a decade, to 6,200 cases a year. According to Cancer Research UK, the HPV virus, which is transmitted to the mouth region from the genitals during oral sex, may be key to the ‘rapid rise’. Statistics also show that the more sexual partners you have the greater your chance of acquiring mouth cancer.

“There is now scientific evidence that a proportion of mouth and throat cancers are linked to HPV infection,” says Hazel Nunn, head of health information at Cancer Research UK. “We know that HPV is found in the mouth but we do not yet know how it gets there – whether through oral sex or otherwise. HPV virus has been found on the fingers and elsewhere on the body. It is possible that oral sex is having an impact but more research needs to be done into the kinds of behaviour that leads to this infection.”

“HPV has been causing mouth cancer for decades but the link is only now becoming clear. HPV is a hardy virus that likes sitting in lymphoid tissue wherever it is in the body,” explains Professor Mark McGurk, a senior consultant ENT surgeon based at London Bridge Hospital in London. That means it thrives in the lymphoid tissue in the mouth, including that of the tonsils and at the base of the tongue. For the same reason, it settles in the cervix, the vulva and around the anus.

For many people, HPV won’t cause any problems at all. “In fact, we know that 80 per cent of women and men will have the HPV infection at some time in their lives and clear it themselves without any symptoms,” explains Mr Mike Bowen, a consultant obstetrician and gynacologist based at St John and St Elizabeth Hospital in London. “But for a few it can cause cellular changes that lead to cancer.”

Professor McGurk says that over the last 30 years, he has seen a rise in oropharyngeal cancer, which typically affects sexually active men in their 50s and 60s. “They may have been infected with the virus for some time and ,” he explains. The cancer reveals itself as growths on the tonsils and back of the tongue.

Many patients are only diagnosed at the late stage of their disease. Michael Douglas, the actor, already had stage 4 cancer when his cancer was recognized. Fortunately, oral cancer caused by HPV is very treatable, even when it is very advanced, using radiotherapy. “We used to do surgery on these cases, but we don’t need to anymore. In many cases, the cancer simply melts away with radiotherapy,” explains Professor McGurk. Patients with stage 1 and 2 Oral cancer caused by HPV have an 85 per cent chance of surviving for 5 years after treatment, and patients with stage 4 disease have a 60 per cent chance of surviving five years – impressive compared to the survival rates for other types of oral cancer where overall survival is 50 per cent over 5 years. [Cancer Research UK]

Cancer research UK is pushing for all mouth tumors to be tested to see if they are HPV positive, to assist with effective treatment of patients. “At the moment, it varies massively depending on what hospital you are in. We think it should be standard,” says Hazel Nunn.

Professor McGurk believes there is a simple explanation why men are more likely to have HPV in their mouths than women. “Women harbor the virus in their genitalia which provides a hospitable environment while the male penile area is a relatively hostile area for the virus to settle.”

One way to try and turn the tide would be to introduce a HPV vaccination for boys and girls before they become sexually active. Girls from the age of 12 in the UK have been offered vaccinations since 2008 against the two most common strains of HPV -16 and 18- which are linked to cervical cancer.

Boys are not offered the vaccine, but this should change, according to Professor Margaret Stanley, a virologist based at Cambridge University who believes that boys must be given the vaccine for HPV too from the age of 12 or 13.

‘Obviously cervical cancer is the big one but the other cancers – cancers of the anus and increasingly the tonsil and tongue – there is no screening for them and no way of detecting them until they are proper cancers and they are more common in men than in women.’

Hazel Nunn of Cancer Research UK points out that there is no evidence that vaccinating boys will help protect them from oral cancer. “It is theoretically possible but there have been no trials that had this as an end point. There is a danger that we get too far ahead of ourselves without evidence-based medicine.”

She insists that although HPV is a worrying factor, by far the most significant risks associated with mouth and throat cancers of all types are smoking and alcohol. “

November, 2016|Oral Cancer News|