Zoster Vaccine Found Effective, Safe in Autoimmune Patients

WASHINGTON — Individuals with systemic lupus erythematosus (SLE) and multiple sclerosis (MS) had fewer herpes zoster (shingles) attacks if they had received the recombinant vaccine against the virus, compared with otherwise similar unvaccinated patients, a researcher reported.

When data from two data sources were analyzed — one of commercial health insurance claims, the other from Medicare — vaccine effectiveness rates ranged from 54% to 81% for SLE and MS patients, according to Michael George, MD, MSCE, of the University of Pennsylvania in Philadelphia.

Meanwhile, lupus exacerbation rates were about the same in vaccinated versus unvaccinated SLE patients, he reported at the American College of Rheumatology annual meeting.

“These data support efforts to increase RZV [recombinant zoster vaccine] vaccination rates among patients with autoimmune diseases,” he told attendees.

He noted that previous studies had shown that many eligible people have not had the shots, even though patients with autoimmune disease are often at increased risk for attacks because of immunosuppressive drug treatments they get for their conditions. Just in the general population, he said, something like 30% of adults will experience zoster episodes at some point.

The current data add to the knowledge base around zoster vaccine effectiveness in the SLE and MS population, for which little specific data had previously existed.

George and colleagues drew on the FDA Sentinel System, which in turn takes claims data from seven commercial insurers in the U.S., and from Medicare fee-for-service records. The time period started in 2018 and extended to 2021-2023, depending on the individual insurer. George reported results separately for the commercial and Medicare databases.

For each data source, vaccinated patients with SLE and MS were matched 1:4 with unvaccinated patients according to age, sex, and diagnosis, using the receipt of the first or second vaccine dose as the index date. Patient totals included in the analysis were as follows:

• Commercial claims, SLE: 1,308 vaccinated, 5,004 unvaccinated
• Commercial claims, MS: 6,025 vaccinated, 22,685 unvaccinated
• Medicare, SLE: 2,284 vaccinated, 9,020 unvaccinated
• Medicare, MS: 8,705 vaccinated, 34,407 unvaccinated

Not surprisingly, Medicare patients were somewhat older on average (mean ages 68-70 vs 61-63), but in other respects the profiles were similar. George acknowledged that the sample was considerably older than the norm for lupus and MS, and didn’t address the largely unanswered questions about the durability of zoster immunity from vaccines in younger patients. The product is approved for patients as young as 18 years if they have immune deficiencies, yet it’s almost exclusively given to older people.

George said there were too few younger people in the databases to allow a meaningful subanalysis. He added that a study specifically addressing zoster vaccine effectiveness over time in younger autoimmune patients is definitely warranted.

George and colleagues looked for incidents of zoster attacks occurring after the index data, as well as lupus flares in the SLE groups. Flares were identified from records indicating new uses of drugs commonly received in such cases, including cyclophosphamide, rituximab (Rituxan), or high-dose steroids, or by hospitalizations for SLE or a related condition such as lupus nephritis, occurring within 90 days after a vaccine dose.

Shingles incidence rates for vaccinated lupus patients were in the range of 5.9-7.4 per 1,000 person-years, depending on which database was analyzed, whereas unvaccinated SLE patients experienced attacks at rates of 15.9-20.0 per 1,000 person-years. Similarly, attack rates in MS patients were 2.4-4.6 with vaccination, as compared with 12.7-13.7 without vaccination, again per 1,000 person-years.

In consequence, hazard ratios for zoster episodes, adjusted for available covariates, such as age, sex, treatment types, comorbidity burden, were 0.30-0.46 in SLE and 0.19-0.36 in MS patients. The differences were highly significant.

SLE flares were considerably more common than zoster attacks, with incidence rates of 90.3-127.7 per 1,000 person-years. But they varied little with vaccination status. George’s group calculated adjusted HRs of 0.78-1.27, depending on database and whether it followed the first or second vaccine dose; none of them came close to statistical significance.

Besides the age issue, George noted that another study limitation was that not all patients were receiving immunosuppressive treatments. He said the researchers plan to perform a subanalysis looking specifically at patients on such medications, and would try to determine if vaccine effectiveness varies among different types. He also said future analyses would look at MS exacerbations.

As it is, he concluded that the study showed that RZV is moderately to very effective in preventing zoster attacks in older SLE and MS patients. As well, the data provide “no evidence of an increased risk of a severe SLE flare” following vaccination.