Vaccines likely don’t work against Omicron, but cheer up: there’s still no sign it’s as deadly as Delta, which is still spreading, too.

(First published Dec. 3 in “What in the World“) As Omicron spreads across the United States, including New York, U.S. President Joe Biden launched a new plan to fight Omicron that will create hundreds of new immunization sites (despite no evidence vaccines work on Omicron) and create an impossible window for international arrivals to get a PCR test before flying to the U.S.

Authorities are emphasizing the importance of getting vaccinated, or, if you’re already vaccinated, getting a booster shot. Germany is punctuating this advice by enacting new restrictions that require proof of vaccination to enter a restaurant or bar.

That’s all well and good. After all, Omicron is still an upstart relative to Delta, which is still surging across Europe and the U.S. The World Health Organization is therefore urging countries to keep pushing vaccines, since vaccines do reduce the risk from Delta and earlier strains.

But there’s still no definitive evidence vaccines work against Omicron. There is, however, plenty of anecdotal evidence they don’t. Many positive Omicron cases being reported involve fully vaccinated individuals. And many people in South Africa who already had Covid are coming down with Omicron, suggesting that antibodies against Covid Classic aren’t effective against Omicron. Another sign that vaccine-induced antibodies and infection-induced antibodies probably don’t work on Omicron is the fact that Omicron has already displaced Delta in South Africa.

The science seems stacked against us with Omicron—each mutation of the virus helps disguise it from antibodies generated to fight its relatives. Eventually they render it unrecognizable. That’s why flu vaccines change every year to match the latest flavor of that virus. The wisest course, if you’re in a community where Omicron has been transmitted locally, is to assume that we’re up against a new pathogen and two pandemics: Delta and Omicron. In the former battle, vaccinated people have some protection against severe illness; against Omnicron, they don’t.

The WHO is also objecting to border closures, saying they don’t help despite ample evidence they absolutely do. The destinations with the lowest infection rates are still those with the strictest border controls, particularly China and Hong Kong. Closing the border and enforcing a quarantine ensures the local population is subject only to its own efforts to reduce transmission, and not victims to some other jurisdictions failure or unwillingness to do their part (hello, U.S. and U.K.!).

The wild card here is that we still don’t know whether or not Omicron causes illness as severe as Delta. There’s still no reports of deaths from Omicron, though that certainly doesn’t mean it hasn’t happened or that it won’t. But the fact that the new stain has been circulating for at least two weeks without causing a surge in Omnicron-related deaths may be cause for at least a glimmer of optimism.