Vaccines Can Not Only Prevent Cancer, But May Soon Be Able to Cure It
HPV is such a common virus that nearly all sexually active individuals will contract the virus at some point in their lives.
It’s estimated that 79 million people (about 1 in 4) are currently infected with human papillomavirus (HPV) and about 14 million people become newly infected each year in the U.S. alone. Yet, there is no cure for HPV and in some cases the virus will develop into cancer years, or even decades, after initial exposure. This results in about 270,000 people who are diagnosed with HPV-related cancers in the U.S. each year to include cancers of the cervix, vulva, vagina, penis, anus or throat.
While the CDC currently recommends that parents get their sons and daughters the HPV vaccine series between the ages of 11-12 to prevent future cases of HPV and HPV-related cancers, the reality is that many people are already infected and are spreading the virus to others.
Good News For Those Already Infected
Mayumi Nakagawa, M.D., Ph.D. from the University of Arkansas for Medical Sciences (UAMS) is researching a new vaccine that is designed to cure HPV, cause pre-cancerous lesions to disappear, and provide future protection against HPV. Following the success of the vaccine’s phase I trials, Dr. Nakagawa is now continuing with stage II trials with the support of a $3.5 million grant by the National Institutes of Health (NIH), over the next five years.
Preventing HPV Infection
Current HPV vaccines are scientifically proven to be both safe and effective in preventing HPV infection. However, to be most effective, boys and girls should complete a three shot series prior to their sexual debut. A recent study showed the vaccine to be 83% effective in preventing the spread of HPV in women who had never come in contact with the virus, but only 53% effective for those who had previous contact with it. An added bonus of getting kids vaccinated at the recommended age of 11-12 years of age is that studies have shown that the vaccine produces a greater immune response with a higher antibody count to fight infection when given at a younger age as opposed to waiting until a child is in their teens.
What Makes This New HPV Vaccine Different?
While this new vaccine doesn’t appear to be designed to replace the current HPV vaccines, it does have the potential to help cure people who have already contracted HPV.
During the phase I study, which involved 34 HPV infected woman, Dr. Nakagawa observed a 90% reduction of the targeted virus in these initial trials. Patients were divided into groups that received different dosages and for those who got the lowest dose — which was determined to be the most effective — their precancerous lesions disappeared in half of the patients in three months. The vaccine also appeared to be effective against the most aggressive form of HPV.
Unfortunately, at the three-month mark, the study participants had surgical procedures to remove the lesions and therefore, the vaccine’s effect on the precancerous lesions could no longer be observed. Plans for phase II will allow for involvement of a greater number of women (80), that will be observed over a longer period of time (12 months). It is hoped that the longer observation period will result in a greater reduction of lesions in a larger number of patients.
If after 12 months there’s no evidence of the virus or cervical lesions, study participants will be considered cured and will not have to undergo any surgical procedures. Surgery typically increases the incidence of preterm delivery, so by leaving the cervix intact the vaccine can also help lower the risk of future preterm deliveries. For women who don’t respond to the vaccine, the study will then pay for them to have the surgical procedure to remove the lesions.
If the clinical trials are successful, and the FDA approves this therapeutic vaccine, it could become the fist line of therapy for people with HPV. It’s estimated that if the vaccine makes it through phase III trials, it could be on the market in seven years.
Curing Cancer Into the Future
It’s quite possible that this vaccine could hold the secret to treating other cancers in the future. As Dr. Nakagawa, explains,
“Part of the vaccine is to stimulate an immune response in general, so it can be used for many other cancers. One thing we are in the very beginning phase is combining it with a part of prostate cancer and seeing whether this can be applied to prostate cancer. So in theory, it can be applied to many other cancers.”
Vaccine innovation like this is exciting. It’s already quite encouraging to know that our current HPV vaccine is capable of preventing cancer. Now, to imagine the development of new vaccines that can help to cure cancer…that’s just another wonderful way that we are using science to help save lives.