Monday, August 22, 2022
What’s the status of the Omicron vaccines? When we will have one, when we should get one, and how come the UK has one and we don’t? We should have more answers soon, because today Pfizer and BioNTech applied to the FDA for an emergency use authorization of their new Omicron vaccine.
Current vaccines: We’ve heard so much about variants over the last two years that it’s hard to believe that the mRNA vaccines we have right now were designed and tested against the original coronavirus, before Alpha, Beta, Gamma, Delta and way before Omicron. The mRNA vaccines developed by Pfizer-BioNTech and Moderna received FDA Emergency Use Authorization in December 2020. This was fast work for vaccines that required 6-month clinical trials. But the virus was faster. Last year when we were talking about what percent efficacy each vaccine had, the target had already changed.
A Feb. 18, 2022, study from the CDC found that giving a third dose of the vaccine boosted protection against hospitalization, but by the fourth month the efficacy began to wane. Still, the study concludes by emphasizing the importance of getting a third dose to reduce incidence of serious illness. (MMWR link below).
Now we are on the verge of having vaccines “against Omicron.” But what does this mean when Omicron itself has many variants?
Omicron vaccine in the UK: The vaccine which the United Kingdom approved last week is a “bivalent” vaccine by Moderna. That is to say, it is a mixture of a vaccine targeted against the original strain of COVID-19 and a vaccine designed to target the original omicron variant BA.1. Focusing on the original omicron variant enabled the vaccine to be developed and produced rapidly.
Omicron vaccine in the U.S. Rather than targeting the original Omicron strain, the FDA asked the companies to make a specific vaccine against the newer BA.4 and BA.5 variants, which are prevalent in the U.S. today. Pfizer and BioNTech have developed a bivalent BA.4/BA.5 vaccine, which they submitted for approval today to both the United States FDA and the European Medicines Agency (EMA). Referred to in the press release as “Omicron BA.4/BA.5-Adapted Bivalent COVID-19 Vaccine,” this vaccine combines mRNA targeting the original SARS-CoV-2 spike protein with mRNA targeting the spike protein of the Omicron BA.4/BA.5 variant. It could be used as a primary series dose, as a first booster, or as a second booster for adults over fifty and immunocompromised individuals over 12.
Controversy: Questions have been raised about the FDA’s decision. For example, the July 14, 2022, NPR interview with science journalist Rob Stein raises these issues: (1) Is it worth it to encode the more recent BA.4/BA.5 when this requirement delays the release of the vaccine, which will always be a moving target anyway? (2) the more updated vaccine may not be much more effective than the original vaccine. (3) the FDA plans to rely on studies in mice to evaluate the new vaccines, instead of studies on humans.
Regarding safety, the modified vaccines are identical to the original Pfizer and Moderna vaccines which have been given to millions of people throughout the world. Only the genetic coding for the virus, is different, and the ability to change this component quickly is a big advantage of mRNA technology. However, there is also the question of efficacy. John Moore, a virologist and professor at Cornell has questioned whether the change to specific Omicron vaccines will provide a significant boost in protection over the earlier vaccines. (See the June 27, 2022, article in Nature.)
Will people be waiting in line in a few months like they were in January last year? That may depend on whether we see a big surge this fall. Or a new Omicron variant. Or both.
Today’s Notable Headlines
“Pfizer asks FDA to greenlight new omicron booster shots, which could arrive this fall,” NPR, Aug. 22, 2022. https://www.npr.org/sections/health-shots/2022/08/22/1118788439/vaccine-maker-asks-fda-to-greenlight-updated-omicron-booster-shot
“Moderna to supply 12M doses of Omicron-targeted COVID shot to Canada,” CBC, Aug. 22, 2022. https://www.cbc.ca/news/health/moderna-to-supply-12m-doses-of-omicron-targeted-covid-shot-to-canada-1.6558285
“Fast-evolving COVID variants complicate vaccine updates,” Nature, June 27, 2022. https://www.nature.com/articles/d41586-022-01771-3
“The U.K. approved omicron-specific booster shots. They’re coming to the U.S. soon,” NPR, Aug. 16, 2022. https://www.npr.org/2022/08/16/1117616159/uk-us-approved-omicron-booster-variant-ba5
“Experts question the FDA’s COVID booster strategy ahead of autumn,” NPR, July 14, 2022. https://www.npr.org/2022/07/14/1111473802/experts-question-the-fdas-covid-booster-strategy-ahead-of-autumn
“What’s behind the FDA’s controversial strategy for evaluating new COVID boosters,” NPR, August 18, 2022. https://www.npr.org/sections/health-shots/2022/08/18/1117778748/whats-behind-the-fdas-controversial-strategy-for-evaluating-new-covid-boosters
“Pfizer and BioNTech Submit Application to U.S. FDA for Emergency Use Authorization of Omicron BA.4/BA.5-Adapted Bivalent COVID-19 Vaccine,” Pfizer, Aug. 22, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-submit-application-us-fda-emergency-use
“Timeline of the COVID-19 variants of concern,” CTV News, Dec. 2, 2021. https://www.ctvnews.ca/health/coronavirus/timeline-of-the-covid-19-variants-of-concern-1.5691314
“Waning 2-Dose and 3-Dose Effectiveness of mRNA Vaccines Against COVID-19–Associated Emergency Department and Urgent Care Encounters and Hospitalizations Among Adults During Periods of Delta and Omicron Variant Predominance — VISION Network, 10 States, August 2021–January 2022,” CDC MMWR. Feb. 18, 2022.
“MODERNA ANNOUNCES OMICRON-CONTAINING BIVALENT BOOSTER CANDIDATE MRNA-1273.214 DEMONSTRATES SUPERIOR ANTIBODY RESPONSE AGAINST OMICRON,” Moderna, June 8, 2022.https://investors.modernatx.com/news/news-details/2022/Moderna-Announces-Omicron-Containing-Bivalent-Booster-Candidate-mRNA-1273.214-Demonstrates-Superior-Antibody-Response-Against-Omicron/default.aspx
Why am I doing this?
The coronavirus pandemic is a classic watershed historical event. People will be referring to “before the pandemic” or “after the pandemic” for decades to come. Since March 11, 2020, this blog has examined the modern pandemic experience, drawing on my background as a medical technologist, a historian, and an ordinary person living through an extraordinary world crisis. My sources, both primary and secondary, are documented with links for easy reference.