Every infection provides a chance for the virus to mutate, and omicron has an edge over its predecessors: It spreads way faster despite emerging on a planet with a stronger patchwork of immunity from vaccines and prior illness.
“The faster omicron spreads, the more opportunities there are for mutation, potentially leading to more variants,” Leonardo Martinez, an infectious disease epidemiologist at Boston University, said.
Omicron is more likely than delta to reinfect individuals who previously had COVID-19 and to cause “breakthrough infections” in vaccinated people while also attacking the unvaccinated.
Along with keeping comparatively healthy people out of work and school, the ease with which the variant spreads increases the odds the virus will infect and linger inside people with weakened immune systems - giving it more time to develop potent mutations.
When new variants do develop, scientists said it’s still very difficult to know from genetic features which ones might take off.
“I have no doubt at all that these viruses are going to continue to mutate and we’re going to be dealing with this for a very long time,” she said.
For a virus that spreads exponentially, he said, “anything that curbs transmission can have a great effect.” Also, when vaccinated people get sick, Ray said their illness is usually milder and clears more quickly, leaving less time to spawn dangerous variants.
Experts say the virus won’t become endemic like the flu as long as global vaccination rates are so low.
Tedros said he’d like to see 70% of people in every country vaccinated by mid-year.
With so many unvaccinated people, he said, “the virus is still kind of in control of what’s going on.”