Summer Academy Meeting highlights benefits of HPV, Herpes Zoster vaccines

Aug 6 2010

Vaccines have a long history of successfully preventing disease and, in effect, improving the lives of countless Americans. Now, two serious diseases - human papillomavirus (HPV) and herpes zoster - could become a thing of the past as people better understand the safety and efficacy of vaccines to prevent these serious viral infections in specific populations.

At the American Academy of Dermatology's Summer Academy Meeting 2010 in Chicago, dermatologist Jeffrey M. Weinberg, MD, FAAD, associate clinical professor of dermatology at Columbia University College of Physicians and Surgeons in New York City, highlighted the significant benefits associated with these two new vaccines.

HPV Vaccine Protects Girls and Boys

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. According to the American Cancer Society's 2010 estimates, approximately 4,210 women will die from cervical cancer in the United States.

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, Dr. Weinberg acknowledged that many people are still reluctant to get the vaccination due to a lack of awareness about who should be vaccinated and when - as well as unease about its association with sexual activity and a general skepticism about side effects.

"The truth is that the HPV vaccine is one of the most effective methods to protect against cervical cancer and genital warts," said Dr. Weinberg. "The vaccine has been proven 99 percent effective to prevent cervical cancer and HPV in patients five years after follow-up and is simply good preventive medicine for the millions of young women and girls who are likely to be exposed to the virus in their lifetime."

In October 2009, the FDA approved another use of the quadrivalent vaccine for the prevention of genital warts due to HPV types 6 and 11 in boys and men, ages 9 through 26.

The effectiveness of the vaccine was studied in a randomized trial of 4,055 males ages 16 through 26 years old. The results showed that in men who were not infected by HPV types 6 and 11 at the beginning of the study, the vaccine was nearly 90 percent effective in preventing genital warts caused by HPV types 6 and 11.

Dr. Weinberg added that another misconception about the HPV vaccine is that it could cause infection upon injection. However, the HPV vaccine is a synthetic vaccine that does not contain a live virus.

"It's not 'biologically possible' to get HPV from the vaccine, which contains no live or killed virus and no virus-like particles," said Dr. Weinberg. "Plus, the most common side effect has been minor pain at the injection site."

Dr. Weinberg also reported that a new bivalent vaccine (one that provides immunity against two viral subtypes) was recently approved for the prevention of three life-threatening cervical diseases caused by oncogenic HPV types 16 and 18 - the two higher risk subtypes.

The primary clinical study for the bivalent HPV-16/18 included more than 18,000 women ages 15-25 in the United States and 11 other countries. Approximately 9,000 of these women received the HPV-16/18 injection and 9,000 received a licensed hepatitis A virus vaccine as a control. Dr. Weinberg added that the results showed that among women who had not already been infected by HPV types 16 and/or 18 before the start of the study, bivalent HPV-16/18 was about 93 percent effective in preventing precancerous cervical lesions caused by these HPV types.

"The clinical findings indicate that the HPV vaccine could contribute greatly to reducing worldwide rates of cervical cancer," said Dr. Weinberg. "In my opinion, protection against the most common sexually transmitted disease and a known fatal form of cancer far outweighs any risks of receiving the vaccine."

Herpes Zoster (Shingles) Preventive Vaccine Benefits Those 60 and Older

It is estimated that there are nearly 1 million episodes of herpes zoster (shingles) annually in the United States, and 15 percent of the population will eventually be affected by the condition. There are several known risk factors for herpes zoster, including a history of chickenpox, advancing age, and a compromised immune system from illness or medical treatments. The primary complication from shingles - associated with the older patient segment - is post-herpetic neuralgia (PHN).

Dr. Weinberg explained that patients with PHN experience severe pain resulting from nerve damage caused by the shingles virus in the outbreak area, as well as beyond the area of the shingles rash. Of the 1 million people who develop shingles, about one in five people will develop PHN, which can last for months or even years. In addition, the chance of developing PHN after having shingles increases with age.

Approved by the Food and Drug Administration (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. Dr. Weinberg added that this pivotal study, which followed patients for a median of 3.1 years, documented an overall 39 percent reduced risk of PHN if herpes zoster develops, and reduced severity if PHN develops - which translates into a considerably improved quality of life for older patients who are good candidates for the vaccine.

"With the herpes zoster vaccine, it's important to understand that it represents a unique use of a vaccine since it is not intended to prevent an infection, but rather to prevent a recurrence of the infection," explained Dr. Weinberg. "Further, the herpes zoster vaccine is specifically aimed at adults age 60 and older, so it is substantially more potent than the traditional chickenpox vaccine to compensate for the reduced immune response found in aging populations."

In addition, Dr. Weinberg noted that another distinction of the herpes zoster vaccine is that it contains a live virus. With that in mind, he cautioned that 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.

"Patients who are candidates for the HPV or herpes zoster vaccine should discuss their concerns or questions with their dermatologist or other physician," said Dr. Weinberg.