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. However, Merck discontinued the sale of Zostavax in the U.S. market as of June 30, 2020.
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.
As per CDC (Center for Disease Prevention and Control), shingles vaccination is recommended for people 60 years and older. This is irrespective of whether or not they recall having had chickenpox, as chickenpox is caused by the same virus as shingles.
However, post this vaccination, protection lasts about 5 years, so people vaccinated before they are 60 years old might not be protected later in life when the risk for shingles and its complications are greatest. Hence, people in the 50 through 59 years age group who have questions about the shingles vaccine should discuss the risks and benefits with a healthcare provider.