This holiday, a collision of omicron and delta looms
The change of expert opinion was sudden. Researchers at Harvard Medical School now say the omicron variant, not delta, is likely fueling the current surge in COVID-19 cases in the northeastern U.S. That’s cause for alarm, because they still don’t know much about the variant, and it’s unclear how well vaccines will protect people. Harvard’s labs are optimized for speed, but omicron is spreading faster than they can track it.
“I think we are in the omicron surge,” Bronwyn MacInnis, director of pathogen genomic surveillance at the Broad Institute of MIT and Harvard, said at a press event Tuesday afternoon. “There’s no system on the planet that could keep up with the pace of this doubling time.”
Though the Centers for Disease Control and Prevention had reported just a few days earlier that omicron probably made up just 3 percent of U.S. infections, she said that’s probably a big underestimate as cases grow by the day. In New York City, the percentage that are from omicron was estimated at 13 percent as of Wednesday.
“We know it’s the most transmissible variant of SARS-CoV-2 we’ve ever seen before, and the most immune-evasive variant of SARS-CoV0-2,” said Jake Lemieux, an infectious disease specialist at Harvard Medical School and Mass General Hospital who is also involved in tracking variants.
Omicron appears to be doubling around every four days. “It’s spread around the globe in under two weeks,” Lemieux said. “It’s a likelihood it will come to your holiday gathering.”
Total COVID-19 cases are surging through the Northeast corridor from Philadelphia to New York City through much of New England — an area that’s well above the national average in vaccination rates. New York state just imposed new mask mandates, and New York City is making vaccines mandatory for children as young as 5 at restaurants and entertainment venues.
At Cornell University, in-person classes were shut down after 900 students tested positive, many with omicron. There were no cases of severe disease, but there was concern that students might infect more vulnerable relatives during the holidays. In a worst-case scenario, cases would rise so fast that even if only a small percentage of infected people got seriously ill in the coming few weeks, their numbers would exceed what hospitals are equipped to handle.
The situation is changing by the hour. The morning before Tuesday’s Harvard Medical School briefing on omicron, I’d heard a very different briefing by Harvard’s T.H. Chan School of Public Health, where the scientists were working under the prevailing assumption we were experiencing a wave of delta. And with delta, those who get the booster shots are unlikely to wind up in the hospital, let alone the ICU. Even without boosters, vaccines will offer some protection against it.
In a delta surge, even the severely immunocompromised wouldn’t have had to be alone over the holidays — though they might have wanted to avoid large gatherings and instead meet in smaller groups with family and friends who agreed to take a rapid test beforehand. The important point is that proven pandemic-fighting tools are available that didn’t exist a year ago.
We might get lucky and find omicron doesn’t lead to widespread severe sickness and death. Scientists have done laboratory studies showing the standard two-dose mRNA vaccines are unlikely to offer much protection against omicron infection, though they might protect against serious disease. And those same experiments suggested that people who get a booster will get about 70 percent or 75 percent protection against symptomatic infection.
But the Harvard Medical School scientists are alarmed at what’s happened since Thanksgiving, when the variant first came to people’s attention. “This is unfolding all around the world in parallel,” Lemieux said.
The good news is that this current situation of fear and confusion won’t likely last long.
In a recent study of Pfizer’s Paxlovid, the most promising of the new antiviral drugs, taking the pill within three days of the onset of symptoms cut the risk of hospitalization by 89 percent for the most high-risk patients. That drug could get Food and Drug Administration approval by the end of the month. By then, much of the fog of omicron confusion will likely have lifted.
But between now and then are many holiday celebrations. One Harvard researcher suggested making them safer by holding them outside and making everyone wear masks. That might be unrealistic since it’s cold out and it’s hard to socialize in a mask, and people usually expect to eat and drink at parties, which can’t be done while masked.
A short period of extra precautions shouldn’t be a big deal, especially for the traditionally more compliant and concerned blue states. But Joseph Allen, the Harvard School of Public Health professor who talked about safe holiday gatherings under delta, has been warning for months that public health officials have brought on pandemic fatigue by pushing an inappropriate level of high alert during the many months when cases were not surging.
Vaccinated people should have been able to enjoy a nearly normal, low-risk summer and early fall. Now the fear is that the public’s reserve of trust and patience has been spent.