Infectious Disease

Study results suggest additional benefits of recombinant flu vaccines

August 08, 2021

Read for 2 minutes

Source / information

Published by:

Disclosure:
Dawood does not report any relevant financial information. Please refer to the study for all relevant financial information from the other authors.

ADD SUBJECT TO EMAIL ALERTS

Receive an email when new articles are published on

Please enter your email address to receive an email when new articles are published on . “data-action = subscribe> Subscribe

We could not process your request. Please try again later. If this problem persists, please contact customerservice@slackinc.com.

Back to Healio

Immunization with recombinant quadrivalent influenza vaccines improved antibody response one month after vaccination compared to egg-based vaccines in a randomized study conducted on medical personnel.

“Most flu vaccines are made by growing flu viruses in eggs. During the development of these egg-based flu vaccines, mutations can occur that can lead to important small differences between the flu virus in the vaccine and the viruses circulating in the real world, ”explains FatimaH S. Dawood, MD, a medical epidemiologist in the influenza division of the CDC.

Source: Adobe Stock.

Recombinant quadrivalent influenza vaccines improved antibody responses compared to egg-based vaccines against three out of four cell-grown vaccine strains one month after vaccination. Source: Adobe Stock.

Fatimah S. Dawood

“These mutations could reduce the vaccine effectiveness of egg-based vaccines. Quadrivalent Inactivated Influenza Vaccines (ccIIV4) and Cell Culture-Based Recombinant Influenza Vaccines (RIV4) are produced using alternative methods that do not involve raising vaccine viruses in eggs, “Dawood told Healio. “Therefore, ccIIV4 and RIV4 vaccines have the potential to be more effective against circulating influenza viruses than egg-based vaccines.”

Unlike egg-based influenza vaccines, which have been around for more than 70 years, cell-based influenza vaccines include vaccine viruses grown in mammalian cells instead of hen’s eggs, and recombinant influenza vaccines are synthetically made and do not use chicken eggs in the production process explained Dawood.

According to Dawood, there are few studies comparing immune responses to RIV4, ccIIV4, and standard egg-based influenza vaccines in adults aged 18 to 64 years. For their study, Dawood and colleagues conducted a randomized study among U.S. health workers in this age group to understand how the immune responses evoked by RIV4 and ccIIV4 compare to the responses evoked by egg-based influenza vaccines in this population.

According to the study, during the 2018-2019 flu season, researchers randomly assigned participants a ccIIV4, RIV4, or IIV4 and collected sera before vaccination and 1 month and 6 months after vaccination. They tested sera by hemagglutination inhibition for influenza A / H1N1, B / Yamagata and B / Victoria and microneutralization for A / H3N2 against cell-grown vaccine reference viruses.

A total of 727 participants were enrolled, of whom 283 received ccIIV4, 202 RIV4, and 242 IIV4. The study showed that one month response to ccIIV4 was similar to IIV4 in terms of seroconversion rate (SCR), geometric mean titers (GMTs), GMT ratio, and mean increase (MFR). However, RIV4 induced higher SCRs, GMTs and MFRs than IIV4 against A / H1N1, A / H3N2 and B / Yamagata. The GMT ratio of RIV4 to egg-based vaccines was 1.5 (95% CI, 1.2-1.9) for A / H1N1, 3 (95% CI, 2.4-3.7) for A / H3N2, 1.1 (95% CI, 0.9-1.4.). ) for B / Yamagata and 1.1 (95% CI 0.9-1.3) for B / Victoria. In addition, the study showed that after 6 months, ccIIV4 recipients had similar GMTs to IIV4, while RIV4 recipients had higher GMTs against A / H3N2 and B / Yamagata.

“The results of the study show a possible additional benefit of flu vaccination with recombinant flu vaccines compared to IIV4,” said Dawood. “However, additional studies are needed to assess how these results translate into real protection against influenza disease and whether these results remain consistent over multiple seasons with different compositions of vaccine strains.”

ADD SUBJECT TO EMAIL ALERTS

Receive an email when new articles are published on

Please enter your email address to receive an email when new articles are published on . “data-action = subscribe> Subscribe

We could not process your request. Please try again later. If this problem persists, please contact customerservice@slackinc.com.

Back to Healio

Related Articles