During the first 42 days, considered the highest-risk period, among these biologic users, researchers found zero cases of varicella (chicken pox), zero cases of shingles and zero cases of hospitalizations for complications like encephalitis (inflammation of the brain with flu-like symptoms) that might be reasonably attributed to the vaccine.

Within the average two years of follow-up, there were 10,098 cases of shingles: 138 cases occurred in those who had been vaccinated – a rate of 6.7 cases per 1,000 patient per year – and 9,960 cases occurring in those who were not vaccinated – a rate of 11.6 cases per 1,000 person per year.

After controlling for all confounding factors – like demographics, type of disease, type of medication used, including oral corticosteroids – researchers found that the vaccine was associated with a 39 percent lower risk of shingles infection.

“This is a critical first step in establishing the safety of the shingles vaccine in this important group of patients,” says Michael Oxman, MD, an infectious disease specialist at the VA San Diego Healthcare System and the University of California. Dr. Oxman, who was not involved in the study, chaired the Department of Veterans Affairs research group that established the vaccine’s safety and efficacy in the general population.

“Shingles is not a disease you can ‘catch’ from someone else,” Dr. Oxman explains. “Once you have had varicella, the varicella-zoster virus is dormant in the body’s nerve cells, and something must happen to wake it up, reactivate it, to cause shingles. Your immunity to the virus must be reduced. People in this study were only moderately immunosuppressed, so they really did not have a greatly increased risk of shingles, even if they were taking biologics.”

The live virus itself used in the shingles vaccine is very attenuated, or weakened, which further reduces the risk, he adds.

That some vaccinated people would develop shingles neither surprises nor worries Dr. Oxman because the current shingles vaccine is not 100 percent effective; it only reduces the risk of shingles in healthy older people by between 50 and 70 percent, and reduces the severity of the disease in those who do get it.  

The finding that the vaccine was not only safe but also effective in immunocompromised patients is also important. “The vaccine appeared to be just as effective in reducing the risk for shingles as we would have expected from the large pivotal trials of this vaccine in healthy older adults,” he adds.

Dr. Oxman notes that in the unvaccinated group, the patients taking corticosteroids – which have long been recognized to increase the risk of developing shingles – had a nearly two-fold higher risk of developing shingles than those not taking corticosteroids.

Both Drs. Curtis and Oxman are calling for a randomized controlled trial to specifically address the safety and effectiveness of the shingles vaccine among immunocompromised patients, including arthritis patients on biologic therapies. “We need larger numbers and carefully collected prospective data in order to definitely answer the safety question and change clinical practice,” says Dr. Curtis. A grant proposal to the American College of Rheumatology for funding has been submitted; no patients are being enrolled at this time.