Clinical and research considerations
For most of the decade evaluated in the study, ACIP recommended vaccination against shingles for Americans aged 60 years and older. The current findings, therefore, do not account for ACIP’s expanding its recommendations in 2017 to include adults aged 50 years and older.
Zostavax is expected to be discontinued this year. It was the only shingles vaccine available before the approval of Shingrix in 2018. The shift to a single product could alter vaccination patterns further.
Ms. Terlizzi plans to continue monitoring trends to “see what changes occur in the next few years,” she said.
Compliance a concern
Data on vaccination rates for shingles are important given the large proportion of the population at risk, Dr. Horovitz said. “People over age 50 who have had chickenpox have a one third chance over their lifetimes to get shingles. That is a lot of people.”
Multiple factors could be contributing to the fact that vaccination rates have hovered around 34% in recent years, he said. “Whenever you see variations in vaccination rates, you have to think about cultural differences and questions about differences in access, accessibility, and attitudes. Attitudes toward vaccines vary widely – from people who don’t believe in vaccination to people who are eager to take vaccinations.
“I don’t know how to dissect all that out of these data,” he added.
Compliance with recommendations also contributes to vaccination rates, Dr. Horovitz said. The fact that in about 10% of people, a flulike syndrome develops the day after being vaccinated with Shingrix can cause some to postpone or rethink immunization, he added. In addition, Shingrix requires two shots. “People have to come back, and that always sets up an issue with recalling someone.”
Marketplace shortages of the Shingrix vaccine could also contribute to lower vaccination rates. However, Dr. Horovitz said that, in his practice, availability was only a problem during the first year after approval in 2017.
On a related note, manufacturer GlaxoSmithKline announced that a decrease in vaccination demand during the COVID-19 pandemic has allowed the supply to catch up. Shingrix no longer qualifies for the CDC’s shortages list, according to a July 9 report.
Ms. Terlizzi, Dr. Horovitz, and Dr. Schmader have disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.