Study finds no connection between COVID-19 vaccine and shingles

After the introduction of COVID-19 vaccines, anecdotal evidence linked the administration of the vaccines with herpes zoster (shingles) infection. A new study published in JAMA Network Open, however, debunks that assertion.

Reviewing data from more than two million U.S. recipients of COVID-19 vaccine, the study authors concluded that the incidence rate ratio of shingles following COVID-19 vaccination was 0.91.

Shingles is caused by the virus that also causes chickenpox.

An incidence rate ratio of less than one indicates that the incidence of shingles in vaccinated individuals is potentially lower than in unvaccinated individuals. The study authors, however, asserted that COVID-19 was “not associated with an increased risk of herpes zoster.”

With a confidence interval of 95%, the study authors estimate that margin of error ranges from 0.82 to 1.01.

The study authors noted that COVID-19 vaccination was associated with a modest decrease in herpes zoster risk compared to flu vaccination before the pandemic.

Subjects in the study could receive a COVID-19 vaccine from Pfizer, Moderna or Johnson & Johnson.

The study period was from December 11, 2020, to June 30, 2021.

A separate study involving more than one million patients published earlier this year reached different conclusions, arguing that the eruption of herpes zoster “may be a rare adverse drug reaction to COVID-19 vaccines.”

A systematic review published in 2021 did not find a definite link between COVID-19 vaccination and shingles but acknowledged that there could be a possible association between the two.

Another report published in 2021 noted five cases of shingles in COVID-19 vaccine recipients. In addition, medical centers worldwide have also published case reports of shingles following COVID-19 vaccination. Although a definitive link between COVID-19 vaccination and shingles has not been established, such case reports have contributed to vaccine hesitancy.

A separate study found that individuals infected with COVID-19 had a 15% higher risk of developing shingles than those not infected with SARS-CoV-2.