Zostavax (Zoster Vaccine Live)

Zostavax was the first shingles vaccine, made by Merck. Unlike today's Shingrix, which contains no live virus, Zostavax used a weakened live form of the varicella zoster virus, the virus that causes chickenpox and shingles. It was given as a single shot, mainly to adults 60 and older, and later approved for people 50 to 59.

Shingrix, a recombinant vaccine approved in 2017, proved more effective, and public health guidance shifted to it. According to the CDC, Zostavax is no longer available for use in the United States as of November 18, 2020. The CDC now recommends two doses of Shingrix for adults 50 and older, including people who previously received Zostavax.

Lawsuits allege that the live virus in Zostavax caused some recipients to develop shingles, sometimes severe or recurring, along with complications such as postherpetic neuralgia, vision problems, and other injuries, and that Merck did not adequately warn of those risks. Merck denies the claims. Federal cases are consolidated as In re Zostavax (Zoster Vaccine Live) Products Liability Litigation, MDL 2848, before Judge Harvey Bartle III in the Eastern District of Pennsylvania, which was still listed as active as of September 1, 2026.

A central issue in these cases is proving that the vaccine strain, rather than the person's own dormant virus, caused the shingles, which typically requires laboratory testing of a sample taken during the outbreak. Most people cannot prove that years later, so many claims face serious obstacles. See our term page on shingles, plus what is MDL and class action vs. mass tort. This page is general information, not medical advice.