U.S. FDA Considers Omicron Component for COVID-19 Booster Vaccines

The U.S. FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) announced it would meet on June 28, 2022, to consider the question: Does the committee recommend the inclusion of a SARS-CoV-2 coronavirus Omicron variant component for COVID-19 booster vaccines in the USA?

This is an essential question for the 175th VRBPAC members to debate since various studies indicate the current FDA-approved COVID-19 vaccines offer limited duration protection from the BA.x Omicron variants, which are dominant in the USA.

The FDA meeting documents disclosed 'That SARS-CoV-2's evolution was apparent within months after the beginning of the COVID-19 pandemic (e.g., D614G mutation) in 2020 and has continued as the virus further adapts to replication in the human host.'

Compared to the prototype strain spike (S) antigen used in currently available COVID-19 vaccines, the Omicron S protein has more than 30 mutations.

'Available data indicate that currently authorized and approved prototype COVID-19 vaccines based on the ancestral Wuhan strain continue to protect the most severe manifestations of COVID-19 caused by predominant SARS-CoV-2 variants.'

'However, this protection is decreased compared to previously circulating variants, is subject to waning (in particular in populations at highest risk of severe COVID-19), and may be further impacted as newly emergent variants become predominant, says the FDA.

Regarding the COVID-19 vaccine waning effectiveness, the FDA highlighted Israel's experience with a second booster dose of the Pfizer-BioNTech (Comirnaty) COVID-19 Vaccine in adults 60 years of age and older indicates that a second booster dose improves VE overall, including through a reduction in mortality (Arbel, et al., 2022; Bar-On, et al., 2022; Gazit, et al., 2022), although effectiveness against mild disease decreased during a 10-week follow-up period.

At a previous VRBPAC meeting on April 6, 2022, the committee discussed considerations that should inform strain composition decisions to ensure that available COVID-19 vaccines continue to meet public health needs, when and how frequently to consider strain composition changes, and the process that should be used for making a recommendation for updating the vaccine strain composition.

Peter Marks, M.D., Ph.D. Center Director, CBER, FDA, will lead off this week's meeting agenda with initial remarks and considerations.

And during the morning session, three COVID-19 vaccine manufacturers - Moderna, Novavax, and Pfizer - will present updated vaccine effectiveness (VE) analyses.

A EUA request for the Novavax COVID-19 Vaccine was discussed and recommended at a VRBPAC meeting on June 7, 2022.

The VRBPAC will consider these questions when finalizing their vote:

• Is a change to the current COVID-19 vaccine strain composition necessary at this time?
• What additional data, if any, would be needed to recommend an updated composition of the primary series vaccine?
• If the booster vaccine composition changes, would continuing use of the prototype primary series vaccine this fall (2022) still be acceptable?

The U.S. CDC recently reported about 66.9% of the U.S. population had been 'fully vaccinated' with an Approve/Authorized COVID-19 vaccine.

And about 47.3% of eligible people have been 'boosted' and are now considered 'up to date' vaccinated.

However, the youngest group (5 yrs+) is only 34% boosted.

The FDA welcomes the digital attendance of the public at its advisory committee meetings and will make every effort to accommodate persons with disabilities.

The FDA provides the public access to a free-of-charge live webcast hosted on YouTube at 8:30 am ET on June 28, 2022.

Note: This FDA information was manually curated for mobile readership.