A record number of influenza vaccine doses will be available for the upcoming flu season. These include two new, higher-strength versions for adults aged 65 years and older, according to the Centers for Disease Control and Prevention.

The additional doses are being produced with an aim to lessen the burden of respiratory illness on the healthcare system during the COVID-19 pandemic, the agency stated Friday. Manufacturers expect to have up to 198 million doses available for the 2020-2021 season, over 20 million more than the agency planned for in 2019-2020. Distribution already has begun and is expected to continue through November.

For older adults, new quadrivalent formulations of high-dose and adjuvanted influenza vaccines are in production. Fluzone High-Dose Quadrivalent (HD-IIV4) is intended to replace the trivalent formulation of Fluzone High-Dose (HD-IIV3). In contrast, the new Fluad Quadrivalent (aIIV4) will be made available alongside the previously licensed trivalent formulation of Fluad (aIIV3). 

Fluad Quadrivalent, like Fluad, contains an adjuvant intended to strengthen the immune response. Older adults tend to have a less robust response to vaccines when compared with younger people.

The CDC’s Advisory Committee on Immunization Practices does not currently favor any of the three available vaccines for older adults. Comparative safety studies, however, have found that “some injection site and systemic reactions were observed more frequently with HD-IIV3 and aIIV3 compared with nonadjuvanted SD-IIV3,” the agency noted.

If none of the three recommended vaccines for elders is available, then other formulations are acceptable options, the agency said. These include “any age-appropriate IIV formulation (standard dose or high dose, trivalent or quadrivalent, nonadjuvanted or adjuvanted) or RIV4,” it said.

In related news, the ACIP also has released guidance on vaccinating people who have active COVID-19 infections. “Clinicians can consider delaying influenza vaccination until the patients are no longer acutely ill,” the ACIP said Friday. “If influenza vaccination is delayed, patients should be reminded to return for influenza vaccination once they have recovered from their acute illness.”