Herpes zoster primary prevention


 * L. Katie Morrison, MD; Associate Editor(s)-In-Chief:

Prevention
Zostavax is a vaccine developed by Merck & Co. which has proven successful in preventing half the cases of herpes zoster in a study of 38,000 people who received the vaccine. The vaccine also reduced by two-thirds the number of cases of postherpetic neuralgia. However, prior to the vaccine, it has long been known that adults received natural immune boosting from contact with children infected with varicella. This helped to suppress the reactivation of herpes zoster. In Massachusetts, herpes zoster incidence increased 90%, from 2.77/1000 to 5.25/1000 in the period of increasing varicella vaccination 1999-2003. The effectiveness of the varicella vaccine itself is dependent on this exogenous (outside) boosting mechanism. Thus, as natural cases of varicella decline, so has the effectiveness of the vaccine.

The intake of micronutrients, including antioxidant vitamins, A, C, E and vitamin B, as well as fresh fruit, may reduce the risk of developing shingles. In one study, patients who consumed less than one serving of fruit a day had three times the risk as those who consumed over three servings per day. For those aged 60 or more, micronutrient and vegetable intake had a similar lowering of risk. A recent study evaluated the effects of two types of behavioral intervention, Tai Chi and health education, on healthy adults, who, after 16 weeks of the intervention, were vaccinated with VARIVAX, a live attenuated Oka/Merck Varicella zoster virus vaccine.

Primary Prevention
Varicella (Chickenpox) Vaccine can prevent this disease. Currently, two doses of vaccine are recommended for children, adolescents, and adults.

Vaccine
A live attenuated VZV Oka/Merck strain vaccine is available and is marketed under the trade name Varivax. It was developed by Merck, Sharp & Dohme in the 1980s from the Oka strain virus isolated and attenuated by Michiaki Takahashi and colleagues in the 1970s. It was submitted to the U.S. Food and Drug Administration for approval in 1990 and was approved in 1995. Since then, it has been added to the recommended vaccination schedules for children in Australia, the United States, and many other countries, causing controversy because it is only expected to be effective for about twenty years, leaving adults vulnerable to the most dangerous forms of infection by this virus. The use of varicella virus vaccine live (Varivax) has been limited by practitioner concerns that adults vaccinated as children could develop severe varicella infection complications if immunity provided by the vaccine is not long-lasting. However, clinical data has proved that the vaccine is effective for over 10 years in preventing varicella infection in healthy individuals and when breakthrough infections do occur, illness is typically mild.

In 2006, the FDA approved Zostavax for the prevention of shingles. Zostavax is a more concentrated formulation of the Varivax vaccine, designed to elicit an immune response in the eldery whose immunity to VZV wanes with advancing age.