Recombinant Flu Shots Provide People Better Protection

The journal Vaccines recently published the results from a study led by University of Pittsburgh scientists that found both recombinant influenza vaccine (RIV4) and standard-dose influenza vaccine (SD-IIV4) effectively prevent influenza hospitalization.

Of the 14,590 individuals included in the primary analysis, the overall RIV4 relative vaccine effectiveness (rVE) was significant when adjusted for propensity scores with inverse probability weights (rVE = 31; 95 % CI = 11 %, 46 %).

Among younger adults (18–64 years-old), overall rVE of RIV4 was significant (rVE = 29; 95 % CI = 4 %, 47 %).

These scientists wrote, "Both RIV4 and SD-IIV4 were significantly effective among all adults against influenza-related hospitalizations during the 2018–2019 and 2019–2020 influenza seasons."

"Relative vaccine effectiveness of RIV4 compared with SD-IIV4 was significant for all adults and younger and healthier recipients."

On June 27, 2023, the CDC Director adopted the 2023-2024 Advisory Committee on Immunization Practices’ recommendations on annual influenza vaccination for everyone six months and older in the United States.

The CDC's recommended timing of flu vaccination has not changed.

September and October are the best times for most people to get vaccinated. Flu vaccination in July and August 2023 is not recommended for most people.

Disclosures: The University of Pittsburgh Institutional Review Board approved this retrospective study using EMR databases. Drs. Zimmerman, Raviotta, Nowalk, and Balasubramani received investigator-initiated grant funding from Sanofi for this project. Drs. Nowalk and Balasubramani have grant funding from Merck & Co., Inc. for an unrelated project.