For more than 200 years, vaccines have played an important role in the prevention of infectious diseases. In the United States, measles, mumps and rubella are now rare diseases thanks to vaccines. Now, two vaccines recently approved by the U.S. Food and Drug Administration (FDA) the human papillomavirus (HPV) vaccine and the herpes zoster vaccine are proving effective in protecting people from serious or potentially life-threatening diseases.
Speaking today at the American Academy of Dermatologys Summer Academy Meeting 2007, dermatologist Stephen K. Tyring, MD, PhD, FAAD, professor of dermatology and professor of microbiology, molecular genetics and internal medicine at the University of Texas Health Science Center in Houston, Texas, discussed the safety and efficacy of these two new vaccines and innovative ways vaccines could be administered in the future.
HPV is a group of viruses commonly linked to the sexually transmitted diseases known as genital HPV infection, which have long been associated with the development of cervical cancer, a life-threatening cancer that the American Cancer Society estimates will claim the lives of 3,670 American women in 2007.
In 2006, a breakthrough vaccine was approved by the FDA for the prevention of HPV types 6, 11, 16 and 18. HPV types 6 and 11 are responsible for more than 90 percent of all cases of genital warts, and HPV types 16 and 18 cause 70 percent of all cervical cancers. Although the vaccine is specifically approved for use in females 9 to 26 years of age, Tyring acknowledged that people are still hesitant about getting the vaccination because of a lack of understanding about who should be vaccinated and when as well as widespread skepticism on the safety and efficacy of all vaccines.
In my opinion, the HPV vaccine is the medical breakthrough of the 21st century, said Tyring. For the first time in history, we have a vaccine that is proven 99 percent effective in study patients five years after follow-up to prevent cervical cancer and HPV. This vaccine has the potential to save countless lives in future generations of women.
Tyring reported that one of the main concerns about the HPV vaccine is the misconception that the vaccine could cause an infection upon injection. However, unlike other vaccines, the HPV vaccine is a synthetic vaccine that does not contain a live virus making it impossible to develop the infection from the vaccination. In addition, Tyring finds that parents are hesitant to vaccinate their young daughters (as young as 9 years old) despite the fact that the vaccine must be administered before the start of sexual activity to be completely effective.
Studies show that younger girls are more likely to be exposed to HPV than older women, which is why some states are considering mandating the HPV vaccine for girls beginning at age 9, said Tyring. If the HPV vaccine is required by law, parents who do not want their daughters vaccinated can opt out without being penalized or fined. But when you look at the facts the protection the HPV vaccine provides against the most common sexually transmitted disease and a known fatal form of cancer how could you not want to protect your daughter when the means are available?
Herpes Zoster (Shingles) Vaccine
Herpes zoster, commonly referred to as shingles, is characterized by a painful, blistering rash that is caused by the same virus that causes chickenpox. An estimated 1 million people will develop shingles in the United States each year, with adults over age 60 being most at risk and prone to more serious complications of the virus.
The recent introduction of the herpes zoster vaccine is a unique use of a vaccine in that it is not intended to prevent an infection, but for the prevention of a recurrence of the infection, explained Tyring. Since this vaccine contains a live virus, there is a chance it could cause the chickenpox infection and should not be administered to anyone who has not had the chickenpox or patients with compromised or weakened immune systems. But for those patients who are good candidates for this vaccine, the potential health benefits are excellent.
Approved by the FDA in 2006 for use in adults age 60 and older, the herpes zoster vaccine was found to be effective in preventing the occurrence of shingles in 51 percent of adults age 60 and older who participated in placebo-controlled trials in the United States. However, Tyring added that even in the 49 percent of patients who developed shingles despite the vaccine, approximately two-thirds of these patients reported a reduction in the severity of their shingles and less pain than in previous outbreaks.
New Non-Injection Vaccines
While the fear of needles will keep some patients from considering the new preventative vaccines, some vaccines are currently being administered by means other than injections via intranasal, oral or topical methods. Tyring suggested that when needles are taken out of the equation, compliance with vaccines increases. He added that vaccines given through topical patches are now under development, as are vaccines being studied for the prevention of genital herpes, HIV, avian influenza and a number of non-viral diseases.
Vaccines approved by the FDA are at least a million times safer than the viruses that they prevent, said Tyring. Patients should discuss any concerns about the new HPV vaccine or the herpes zoster vaccine with their dermatologist to determine if they are good candidates for these vaccinations.
Source: American Academy of Dermatology