Zostavax is a live attenuated virus vaccine used to protect from herpes zoster, more commonly known as the shingles virus. Zostavax was developed and produced by the New Jersey pharmaceutical company Merck & Co, one of the world’s largest vaccine manufacturers. It is used in individuals 60 years of age and older.
Zostavax was approved and licensed by the U.S. Food and Drug Administration (FDA) in May 2006. Later, in 2011 FDA approved the live vaccine for use in individuals aged between 50 to 59 years of age. The Advisory Committee on Immunization Practices (ACIP) in June 2011, the vaccine for adults aged 50, through 59 years was refused and reaffirmed the recommendation for adults aged 60 years and older. Later, the FDA approved the expanded indication for Zostavax in March 2011 for adults aged 50 through 59 years.
FDA had approved two important changes to the warning label of Merck Pharmaceuticals shingles vaccine, Zostavax, following the shingles controversy.
August 2014: The vaccine, in addition to potentially causing chickenpox, also causes shingles were added to the warning label. A vaccine that was marketed to prevent seniors from contracting the condition was found to cause shingles in some individuals. Another potential side effect to be mentioned on the warning label was Eye Disorders: necrotizing retinitis.
UCLA researchers found that only one in 175 people who get the vaccine will be able to evade a shingles flare-up. Whereas Merck claimed Zostavax is 50% effective, in the placebo group, 3.3 percent of the study participants developed shingles, compared to 1.6 percent in the vaccine group. Thus, while there is a 50% difference, the real risk reduction is just 1.7 percentage points.