Pfizer files for emergency use of its BA.4/BA.5 Omicron booster

Trays of Pfizer COVID vaccine vials
Trays of Pfizer COVID vaccine vials

Camosun College / Flickr cc

As the nation braces for another possible spike in COVID-19 activity, Pfizer and BioNTech today announced that they have submitted an application to the US Food and Drug Administration (FDA) for emergency use of its bivalent (two-strain) booster that targets the BA.4 and BA.5 Omicron variants.

Shipping could begin in September

mRNA vaccine makers have been working on bivalent booster shots targeting the original Omicron variant, but in late June FDA vaccine advisers recommended that the boosters include the more recent BA.4 and BA.5 subvariants. The more transmissible viruses, also known to evade earlier immunity from vaccines and previous infection, have fueled outbreaks in several countries and led to persistently high levels in many US communities over the summer.

The nation's COVID-19 activity has been at a stubbornly elevated level this summer, and officials worry about more surges as schools resume and people gather indoors as the weather cools.

In a statement, Pfizer said its EUA would clear the booster for use in people ages 12 and older.

The company said the clinical trial is expected to begin later this month, but it has already scaled up production and will be ready to ship the vaccine in September, as soon as the FDA approves the emergency use authorization (EUA) application.

To speed the consideration of the EUA, the FDA told Pfizer it could submit clinical data for its bivalent BA.1 vaccine alongside preclinical and manufacturing data on its BA.4/BA.5 vaccine. Preclinical data in animals suggest that the BA.4/BA.5 bivalent booster prompts a strong neutralization antibody response against Omicron BA.1, BA.2, and BA.4/BA.5 variants, as well as to the original SARS-CoV-2 virus.

Pfizer also said it will complete a rolling submission to the European Medicines Agency in the coming days.

On Twitter today, Ashish Jha, MD, MPH, coordinator of the White House COVID-19 committee, said vaccines are one of the first-line defenses against COVID-19 heading into the fall. However, he said too many kids and adults don't have adequate protection against BA.5. "Being up to date will help a lot." He added that school vaccine clinics will help kids and teachers get vaccinated and boosted.

New CDC data on COVID-19 cases and deaths show that people ages 50 and up who have had one booster dose have an 83% reduction in deaths, and those with both recommended booster shots have a 94% reduction in death. Only 11% of those ages 50 to 65, however, have two booster doses, with the level a little higher, at 26%, in seniors.

FDA OKs Novavax for teens, asks for more Paxlovid research

In other US developments with COVID-19 countermeasures, the FDA on Aug 19 authorized emergency use of the Novavax primary vaccine series for children ages 12 to 17.

In July, the FDA approved an EUA for the vaccine for adults, the fourth for the US market. The vaccine is made on a more traditional production platform, which officials hope will sway more people to get vaccinated.

The vaccine contains the SARS-CoV-2 spike protein produced in insect cells. It contains the Matrix-M adjuvant to boost immune response.

Meanwhile, the FDA has asked Pfizer to do research on a second course of the antiviral drug Paxlovid in people who experience rebound infection after the first course, according to Bloomberg News. It asked the company to report initial findings on the second course by the end of September. A Pfizer official told Bloomberg that the company is working with the FDA on a research protocol.

In other US developments:

  • Anthony Fauci, MD, today announced that in December he will be stepping down from his roles as director of the National Institute of Allergy and Infectious Diseases (NIAID) and as chief medical officer to President Joe Biden to pursue the next chapter of his career. Fauci, who is 81, has served as NIAID director for 38 years, advised seven presidents, and help steer the nation through several infectious disease crises.

  • First Lady Jill Biden left isolation yesterday after testing negative for COVID-19 twice, according to the Associated Press. Biden had tested positive on Aug 16. She was prescribed Paxlovid and isolated at a South Carolina beach home where she and the president were vacationing. President Biden recovered from his rebound infection on Aug 7.

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