Other preliminary research has found that the latest subvariants are more pathogenic and can potentially evade even the immune protection that comes from a previous Omicron infection.

The big picture: Clinical trials are underway to study tweaked versions of the Pfizer and Moderna vaccines, and the FDA has said it will decide this summer whether to recommend these updated versions for use later this year.

A leading option is to target multiple variants, including Omicron, with the same vaccine. But the Omicron version that’s around in a few months may be significantly different than the strain the vaccine was designed to target.

Between the lines: Although the vaccine manufacturers have said they can quickly adapt to produce new vaccine versions, collecting data on those vaccines’ effectiveness through real-world clinical trials takes time.