Image of Rochelle Walensky, M.D.
CDC Director Rochelle Walensky, M.D.; Image credit: Massachusetts General Hospital

The omicron coronavirus variant appears to be reinfecting people at three times the rate of the delta and beta variants in South Africa, where it is now the dominant strain, according to reports from that country. But Americans should remain focused on the delta variant for now, says the director of the Centers for Disease Control and Prevention.

Omicron has been detected across more than one-third of U.S. states, and scientists are hurrying to answer questions of how infectious and deadly it might be to Americans. But for now at least, delta remains the dominant strain stateside, causing 99.9% of current cases, Rochelle Walensky told CNN Friday.

“[W]e know what we need to do against delta, and that is get vaccinated, get boosted if you’re eligible and continue all of those prevention measures including masking. And those are very likely to work against the omicron variant,” Walensky said.

In the meantime, COVID-19 vaccine makers have contingency plans in place to fight omicron and other new variants if needed. This includes making a combination vaccine that would protect against both the original version of SARS-CoV-2 and the new variant. Their plans also include development of a variant-specific booster dose, the White House’s infectious disease expert Anthony Fauci, M.D., told reporters at a White House briefing.

“They are now assuming they may have to do that and are being prepared for that,” Fauci said, as reported by Reuters.

However, data from the National Institutes of Health suggest that the vaccines currently in use, along with the available booster shots, will still be protective, he added. 

“Although we haven’t proven it yet, there’s every reason to believe that if you get vaccinated and boosted that you would have at least some degree of cross protection, very likely against severe disease, even against the omicron variant,” Fauci said.

A recent study from the United Kingdom has shown that the current mRNA vaccines — Moderna’s and Pfizer-BioNTech’s — have the biggest impact on antibody levels when given as boosters shots.

“A third dose will be effective for many of the vaccines we’ve tested and in many different combinations,” said study lead Saul Faust, Ph.D., an immunologist at the University of Southampton, U.K., according to Reuters.