After historic declines of the virus, cases of the highly infectious strain of group A Streptococcus spiked in the fall of 2022, drawing concern from experts. Now, the CDC says the flu vaccine may reduce the risk for strep A.
The increase in infections was likely caused by lack of protective immunity due to COVID-19 isolation restrictions, which may have "predisposed children to [invasive group A strep] infection when pandemic restrictions were lifted," the CDC noted.
A study by the CDC's Emerging Infections Program of cases in patients with strep A revealed, "The proportion of patients with preceding or concurrent influenza infections suggests that influenza vaccination might reduce the risk for [invasive group A strep], as has been demonstrated for varicella vaccination," according to the CDC.
Although strep A commonly infects pediatric patients, the agency urges clinicians to consider strep A for anyone presenting with severe illness, including those age 65 and older, and to now offer flu and varicella vaccines for anyone who is not up-to-date with those vaccines.