On Nov. 26, the World Health Organization declared Omicron the latest COVID-19 variant of concern, and vaccine makers jumped on the news. Moderna quickly announced that it was developing an Omicron-specific vaccine, while continuing to study both a higher dose of its currently authorized shot, and a combination vaccine that protects against one of the previous SARS-CoV-2 variants. BioNTech, which developed its vaccine with pharmaceutical giant Pfizer, began studying whether its existing two-dose shot continues to protect against Omicron, and a company spokesperson said those results could be available in about two weeks. In the meantime, Pfizer-BioNTech are also preparing an Omicron-targeted vaccine that could take six weeks to develop, plus another several months to test—which means if needed, that vaccine could be available next spring.
Both Moderna and Pfizer-BioNTech developed their COVID-19 vaccines using mRNA technology, which allowed them to quickly move from getting the right genetic sequence of the SARS-CoV-2 virus and inserting it into their shots to generate a robust immune response. The technology is highly adaptable and means that additional vaccines, directed against new genetic targets on the virus, such as Omicron, will take weeks rather than years.
Whether a vaccine targeted directly against Omicron will be necessary, however, depends on the results of studies that pit existing vaccine-induced antibodies and immune cells against the variant in a lab. If the current protection from vaccines continues to control Omicron, then it will be even more critical for people to get a booster shot of the existing authorized or approved vaccines. That additional dose will enhance protection and likely keep people who are infected with Omicron from getting severely ill with COVID-19.
If, on the other hand, the studies show that the existing vaccine protection against Omicron is weak, public health officials and vaccine makers will have to decide two things: first, whether people need to be re-vaccinated against Omicron with two doses of a a new, variant-specific mRNA vaccine; or if a booster with an Omicron-targeted dose will be enough.
Vaccine makers using other technology, such as Johnson&Johnson-Janssen and AstraZeneca, are also testing how their shots fare against Omicron. Their vaccines introduce snippets of genetic material in the form of DNA to the body, so cells can then produce viral proteins that the immune system targets. AstraZeneca launched studies in Botswana and Eswatini, two of the nations where Omicron cases have been reported.
The latest variant isn’t a surprise to vaccine and public health experts, who warn that other variants like it are inevitable if vaccination rates remain low around the world. Viruses mutate when they copy their genetic material to duplicate themselves—basically, when they infect someone. The more infections and the more copying the virus squeezes in, the more opportunities it has to generate mutations and variants like Omicron. Vaccines dampen the virus’ ability to replicate, so creating some vaccine-based defense by getting good vaccine coverage in as much of the population as possible is the best weapon against any new, potentially more contagious and dangerous variants.