How Vaccine Makers Are Tackling the Omicron Variant

vaccines vs omicron variant

Verywell Health / Jessica Olah


On August 31, the FDA authorized the "bivalent" formulations of the Moderna and Pfizer vaccines which combine their currently-authorized COVID-19 booster with an Omicron-specific booster. The Moderna bivalent booster was authorized for individuals 18 years and older and the Pfizer booster was authorized for individuals 12 years and older.

Key Takeaways

  • Omicron, a variant of concern, contains mutations that may make it more transmissible and vaccine-resistant than other COVID-19 variants.
  • Vaccine manufacturers including Pfizer, Moderna, and Johnson & Johnson are testing whether their COVID-19 vaccines protect against the new variant.
  • At the same time, the companies are exploring other ways to tailor their vaccines, including the development of Omicron-specific formulations.

COVID-19 vaccine manufacturers are racing to find ways to tweak or reformulate their vaccines to protect against the newly identified Omicron variant.

So far, there's no available data on how the current COVID-19 vaccines will hold up against the new variant. Omicron, classified as a variant of concern by the World Health Organization, has around 50 mutations, and it could be more infectious than the Delta variant.

Pfizer-BioNTech and Moderna said they're testing whether the current vaccines induce sufficient immunity against Omicron to prevent serious illness and death. Both companies are gearing up to develop a new vaccine tailored to Omicron’s unique mutations if necessary.

It will take at least two weeks to sequence the variant and gather more information on how Omicron compares to other variants in terms of transmissibility and likelihood of severe illness.

While researchers learn more about Omicron, getting vaccinated remains the best way to protect yourself and others from disease, said Purvi S. Parikh, MD, an allergist and immunologist at NYU Langone and the Allergy and Asthma Network.

“Do not panic, but prepare,” Parikh told Verywell in an email. “If not yet vaccinated, get your vaccine as soon as possible. If due for a booster, get your booster.”

Creating Contingency Plans

Researchers will first test whether the current vaccines can ward off severe outcomes like hospitalization and death from the Omicron variant.

“There's no point of making major changes to the vaccines that we're currently using unless we see a real clear benefit to do that,” Robert Bollinger, MD, MPH, professor of medicine and infectious diseases at Johns Hopkins University, told Verywell.

Major vaccine manufacturers had developed shots for earlier variants, including Delta and Beta, and sent them to clinical trials. But these versions were never distributed as the original formulas proved to hold up against these variants.

Moderna said in a statement that it would first test whether doubling the dosage of its 50-milligram booster shot would induce a stronger immune response against the new variant. If not, the company will test two booster candidates previously created in anticipation of viral mutations like some of those seen in Omicron.

If the data shows that Omicron significantly reduces the neutralizing antibody or T-cell response generated by the current vaccines, manufacturers may turn toward a new formulation designed for Omicron, Parikh said.

Moderna, Pfizer, and Johnson & Johnson all announced that their companies are ready to adapt an Omicron-specific vaccine.

mRNA Vaccines Are Designed to Be Adaptable

The Pfizer vaccine was praised as a milestone for biotechnology partly because mRNA can be easily edited to tackle new viral strains.

Scientists may isolate the genetic code for a new viral variant, swap it in, and create a new formula to spur the creation of proteins that are designed to protect vaccinated people against the new variant.

Omicron has 32 out of 50 mutations on its spike protein—the coating that allows the coronavirus to enter human cells. But vaccine makers can predict variants by tracking viral mutations around the world, and they routinely create vaccine candidates against mutations, Parikh explained.

“Knowing that the spike protein is the target of most vaccines, they can come up with vaccines with newer targets on the spike itself in case a mutation leaves the old target unrecognizable," she said.

Pfizer CEO Albert Bourla said the company could develop a reformulated vaccine retrofitted for the Omicron variant within six weeks and distribute initial batches in 100 days.

Bollinger said this turnaround is “incredibly fast,” thanks to advancements in vaccine development over the past several decades and investment in research in the last two years.

“What I think people need to remember is that the fact that it's fast doesn't mean it's less safe or less effective,” Bollinger said.

After a reformulation is finished, Pfizer must go through FDA-mandated safety protocol to ensure that the vaccine works and doesn’t produce any major adverse effects. The FDA requires at least two months’ worth of safety data before it will consider a drug for emergency use authorization.

The FDA may not require Pfizer to undergo a clinical trial to grant authorization of an Omicron-specific vaccine, based on data from vaccines for the Beta and Delta variants, Mikael Dolsten, Pfizer’s chief scientific officer told STAT. If a trial is required, the company could have the data completed by early March 2022, according to Dolsten.

Do Current COVID-19 Vaccines Still Work?

Until more data suggests otherwise, the current COVID-19 vaccines and boosters are the best way to protect yourself and others. Plus, more than 99% of the current COVID-19 cases in the United States are caused by the Delta variant, per the Centers for Disease Control and Prevention.

“We should really be pushing hard and fast to get everybody fully vaccinated and boosted if needed,” Bollinger said. “That's the best strategy to prevent transmission. If you prevent transmission, you’ll prevent mutations. If you prevent mutations, you prevent variants. That’s what we need to do not just here but around the world.”

Other tried-and-true mitigation strategies are also key to driving down infections, he added.

“The good news is that there's no evidence that masking, distancing, hand-washing, and good ventilation is going to be any less effective with Omicron than it is for other variants,” Bollinger said.

What This Means For You

Experts say the best way to protect yourself against any variant of COVID-19 is to be fully vaccinated and receive a booster shot. Other strategies—like wearing well-fitting masks in public spaces and getting tested when you feel sick—remain key to limiting the spread of Omicron and other variants.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. World Heatlh Organization. Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern. Published November 26, 2001.

  2. Centers for Disease Control and Prevention. Monitoring Incidence of COVID-19 Cases, Hospitalizations, and Deaths, by Vaccination Status — 13 U.S. Jurisdictions, April 4–July 17, 2021. Morbidity and Mortality Weekly Report. September 17, 2021. 70(37);1284–1290.

  3. Food and Drugs Administration. Emergency Use Authorization for Vaccines Explained. Updated November 20, 2020.

  4. Centers for Disease Control and Prevention. COVID Data Tracker: Variant Proportions. Updated November 27, 2021.

By Claire Bugos
Claire Bugos is a health and science reporter and writer and a 2020 National Association of Science Writers travel fellow.