Merck faces a growing number of lawsuits over Zostavax, not only alleging that the vaccine fails to protect against shingles as advertised, but also indicating that side effects may cause a persistent strain of the infection, along with serious complications, including death.

A group of 15 plaintiffs filed a Zostavax lawsuit (PDF) in the Superior Court of New Jersey on July 20, claiming that the vaccine caused the development of a persistent strain of herbes zoster, more commonly known as shingles.

Shingles is caused by the same virus, varicella zoster, which causes chickenpox. Later in life, the virus can be reactivated and cause shingles, which is a painful rash that usually appears as a stripe of blisters on the body. Pain can continue even after the rash is gone, which is known as postherpetic neuralgia.

To prevent shingles, adults can get a chickenpox or shingles vaccine. Zostavax was approved in May 2006, for the prevention of shingles among individuals ages 60 or older. It is a more potent version of the Merck chickenpox vaccine, Varivax.

According to the lawsuit, Zostavax failed to perform as advertised and even increased the risk of shingles, plaintiffs maintain, due to its use of live virus.

“A risk of using a live virus vaccine is that it is not weakened enough or ‘under-attenuated.’ Under-attenuated live virus creates an increased risk of developing the disease the vaccine was to prevent,” the lawsuit states. “Once injected, attenuated live virus has been shown to recombine into more virulent strains causing disease.”

The complaint indicates that by September 2015, there were already 1,111 reports of severe Zostavax problems identified among adverse event reports, including 36 deaths. Many of the reports were linked to viral infections of the central nervous system, resulting in side effects such as acute disseminated encephalomyelitis, peripheral neuropathy, myalgia, arthralgia, rashes, severe cutaneous disease, herpes keratis that caused vision loss, pneumonia, brain inflammation, facial paralysis and death.

Shingles itself can cause scarring, bacterial infections, encephalitis, hearing loss, vision problems and other complications.

The Zostavax lawsuit presents claims for negligence, designing a defective product, failure to warn, breach of warranty, misrepresentation, unjust enrichment, and strict liability. The plaintiffs are seeking compensatory and punitive damages.

In addition, some have estimated that thousands of future lawsuits may be filed in courts nationwide over Zostavax side effects.

Tags: Merck, Shingles, Vaccine, Zostavax