Q: What kind of effectiveness has been observed in women who got the HPV vaccine in the long term?
A: Australia had provided free HPV vaccines to 12-18 year old girls in a school-based program. Researchers observed that the proportion of women under 28 years old with genital warts decreased by 25%.
Q: How was the frequency of the occurrence of HPV infection in heterosexual men affected when only girls were vaccinated?
A: Heterosexual men had a 5% decrease in genital warts.
Q: Why did heterosexual men who were not vaccinated experience a decrease in their chances of acquiring an HPV infection when only the girls were vaccinated?
A: This observed effect is the result of the “herd immunity. ” The efficacy of the HPV vaccination in females led to less of a reservoir of the HPV virus in women that was available to infect heterosexual men.
Q: Was this herd immunity effect seen in all heterosexual men?
A: The decreased incidence of genital warts was seen predominantly in younger heterosexual men. Younger men tend to have sex more frequently with women their own age or younger. If these women were already vaccinated and immune to HPV at the time that they sexual contact with an older male partner who already had an HPV infection, they will not get the infection and cannot subsequently infect a guy their own age with whom they have sexual contact.
Q: Was there any advantage to gay men when women were vaccinated?
A: Gay men did not gain any improved chances of a lower chance of getting genital warts when women alone are vaccinated.
Q: How do you also protect the gay population from HPV infection?
A: Widespread vaccination of all men will most likely result in a statistically decreased occurrence of HPV infection in both heterosexual and gay men and will provide protection against both genital warts and the numerous HPV-related cancers.
Q: Should all men be vaccinated?
A: There is an enormous advantage for all men (heterosexual and gay) to get vaccinated. Being immunized against HPV infections decreases the man’s chances of getting HPV infections that can cause genital warts as well as any one of numerous HPV-related cancers. Men will also be spared the medical, psychological, social and economic penalties of having an HPV infection.
Q: Why do we hear so much about HPV and vaccination in women but so little about HPV and vaccination for men?
A: Most of the pioneering work on HPV was done by physicians and scientists who were concerned about the association of HPV with cancer of the cervix. Women had a naturally occurring advocacy group in this regard. Physicians were searching for better ways to improve the early diagnosis and treatment of women with high risk HPV and with precancerous and cancerous lesions. Research in the field of HPV exploded and once a certain level of understanding of the HPV virus was achieved a vaccine was developed.
Q: What were the initial concerns about men with HPV?
A: The attention to men with HPV focused on men as being carriers of the HPV virus that could infect women. The interest in men was related to the importance of the male factor in causing cancer of the cervix. There was little discussion of the direct health issues men might have if they were infected with HPV until recent years.
Q: Why was the field not looking closely at the effect of HPV on men?
A: The HPV field is strongly oriented towards the prevention and treatment of disease in women. When HPV infections at other sites are always initially examined using the research models perfected through the study of cervical cancer. Historically, relatively little attention in the HPV literature has been devoted to the diagnosis, treatment and prevention of HPV infections in men.
Q: When was the HPV vaccine for men developed?
A: The HPV vaccine was demonstrated to be safe and effective in women. The vaccines were subsequently FDA approved for use in the United States for women. Gardasil (Merck) was approved as a vaccine for women in 2006 and Cervarix (GSK) was also approved as a vaccine against HPV. Merck subsequently submitted data demonstrating that their HPV vaccine (Gardasil) was also safe and effective in men and Gardasil was approved for men in 2009.
Q: Was the HPV vaccine for men developed in order to address concerns about the effects of HPV in men?
A: The main driving force of the medical and scientific community as well as the marketing strategy for the vaccine companies was to get men vaccinated in order to decrease the number of men in the population who can infect women. The data submitted to the FDA for approval of the HPV vaccine (Gardasil) for men demonstrated that the vaccine decreased the incidence of genital warts in men and also decreased the incidence of a precursor growth of anal cancer.
Q: Why are we now hearing more people encouraging men to be vaccinated?
A: The main concern of the gynecologic community, who are the natural advocacy group of women, is to increase the protection of women from HPV. In recent years it has been increasingly recognized that if men are also given the opportunity to be vaccinated there would be a decreased prevalence of HPV in both the female and male population.
Q: Why didn’t they advocate that men should also be vaccinated as soon as the vaccine was available?
A: The initial plan was to decrease the total amount of HPV in young women by having women exclusively vaccinated. Not enough women volunteered to receive the full three shots of the vaccine, which would not only protect them but also establish a significant herd immunity response in the population that would result in a significant decrease in the prevalence of HPV in the general population. Men therefore also needed to be targeted to be vaccinated, in order to decrease the amount of HPV in the general population so that fewer women would be exposed. There has subsequently been an increased recognition of the importance of addressing the numerous HPV-related infections, precancers and cancers which occur in men, and an appreciation of how the vaccine may also help to prevent these conditions.
Q: How percentage of women do physicians think need to be vaccinated in order to make a significant impact on the immunity of the entire population against HPV?
A: Although the HPV vaccine is recommended for girls up to 21 years of age (up to 26 years old under certain circumstances), only 35% of the female population in those age ranges in the United States had received all three vaccinations. 70+% of women need to be vaccinated in order to get a significant herd immunity effect in the entire population.
Q: Was vaccinating men a consideration early on?
A: The vaccine is very expensive. Health care economists and government policy scientists determined that the most cost effective way to protect women from getting an HPV infection would be to focus their efforts solely on getting as many females of the appropriate ages vaccinated. Vaccinating men was initially considered a non-cost effective approach to decreasing the incidence of cervical cancer in women so men were not initially targeted to get the vaccination.
Q: What consideration was given for the potential advantages to men of being vaccinated?
A: The protection of men against HPV infections including genital warts, and HPV-related cancer was not initially the main focus of discussion. The discussion was focused on how to achieve the greatest amount of protection for women.
Q: What is the long term advantage of HPV vaccination in reference to decreasing the chances of cancer?
A: The HPV vaccine has been demonstrated to effectively prevent the growth of cervical cancer precursors caused by high risk HPV DNA in women. Studies were designed to detect the appearance of cervical cancer precancers as an endpoint because it would be unethical to wait to allow a cervical cancer to develop. Protection against genital warts caused by low risk strains was also demonstrated. The decrease in the incidence of both precancerous growths and genital warts indicated that the vaccine is effectively boosting the immune system against both the high and low risk strains of HPV in the vaccine.
Q: What evidence is there that the HPV vaccine will also protect against HPV-related cancers?
A: The incubation period for the HPV virus to grow out into genital warts is 3-6 months. The fact that there is a significant decrease in genital warts indicates that the vaccine is working. Cervical cancer takes 20-30 years to develop from the time of the initial HPV infection. Other HPV-related cancers in differ anatomic locations (anus, rectum, oropharynx, penis) also take a long time to grow . The decreased incidence of precancerous lesions is taken as a proxy and encouraging suggestion that the long term incidence of other HPV-related cancers similarly caused by the high risk strains may also be decreased. The increased protection against the high risk strains of HPV should also decrease the chances of the development of other HPV-related cancers.
Q: Are studies currently being done on the effectiveness of the HPV vaccine in preventing the development of HPV-related cancers?
A: Long term studies of the effectiveness of the HPV vaccine against numerous HPV-related cancers are underway. The final data will not be available for many years because HPV-related cancers can take 20+ years to grow out. The preliminary data will be released intermittently as the results come in.
Q: What are the conclusions from the Australian study of young women who had received the HPV vaccine?
A: The marked the reduction in the occurrence of genital warts in women in the year following vaccination supports the efficacy of the vaccine. The reduction in genital warts among non-vaccinated heterosexual men but not among non -vaccinated gay men is consistent with reduced heterosexual transmission of HPV as a result of female vaccination due to herd immunity.
Q: What screening methods can be used in men to detect whether they have an HPV infection?
A: The relatively simple and straightforward screening methods available to women are not available to men. Men who see or feel a growth(s) in their genital area or who have been informed by their partner that they have an infection need to be evaluated by their physician in order to determine their status.
Q: Is there a blood or urine tests that serve as a screen for HPV infections?
A: There is no effective blood or urine test for HPV in either men or women.
Q: Do men have a greater chance of getting genital warts than women?
A: Men develop genital warts more frequently than woman.
Q: Why do men develop genital warts more frequently than woman?
A: Women are able to mount a more robust antibody level response to HPV infections than men, which gives them a higher resistance to infection.
Q: What is the difference between a man and a woman’s immunity to HPV?
A: Men do not develop antibodies as frequently as women, and when they do they have lower antibody levels.
Q: Why are men not able to produce antibodies as effectively as women?
A: The body has a much more difficult time forming antibodies against growths on the surface of the skin (i.e. penis) than on moist surfaces (i.e. vagina, cervix).
Q: Are the numbers of anal and rectal cancers increasing?
A: The incidence of anal and rectal cancers is increasing in heterosexual and gay men as well as in women. The rate of increase of anal and rectal cancers in gay men is especially high and this is worrisome.
Q: How does the number of cases of invasive cervical cancer in women compare to the cumulative number of HPV-related cancers which occur in men?
A: The screening methods against cervical cancer in the United States have driven down the incidence of invasive cervical cancers to a number that is lower than the cumulative number of HPV-related cancers which occur in men. The continued screening of women for cervical cancer continues to be of critical importance.