Learning from New York’s omicron variant surge
Studies have shown that omicron is better able to evade vaccine immunity than previous strains, and health officials across the country are urging booster shots, which appear to reduce transmission and prevent severe illness.
On Tuesday, New York state’s case rate was 87 cases per 100,000. It tripled in less then a month and now is more than four times California’s case rate of 19.6. New York City, in particular, is seeing a surge in cases, though case rates are high statewide.
Hospitalizations are also inching up in New York with 20 hospitalizations per 100,000, doubling in a month and compared with 8.7 in California.
That’s still far lower than the 46 per 100,000 hospitalization rate New York logged in January 2021, and nowhere close to what it saw in April 2020. So far hospitals are not yet being overwhelmed as they were at the outset of the pandemic and say they feel equipped for the omicron surge. The main concern is staffing shortages and the potential for more breakthrough infections in staffers.
UCSF infectious disease expert Dr. Peter Chin-Hong said “lots of traffic” from travel, combined with “density and crowding” and many people congregating indoors in the winter weather, has made New York “ripe for transmission.” He added that omicron was likely already spreading in New York long before the travel ban from southern African countries.
The rapid upswing in cases has come at a difficult time for New York City, which is usually flooded with visitors to celebrate the holiday season and ring in the New Year. Positive tests cropping up among Broadway show crew and cast members and restaurant employees have forced cancellations and closures, and the New Year’s Eve celebration in Times Square is up in the air. The state’s top health official, who is vaccinated and boosted, tested positive for the virus.
But New York Gov. Kathy Hochul said on Monday that it is not the same as March or December 2020, and there won’t be a shutdown because of the tools available now, including vaccinations and boosters.
New York City Mayor Bill de Blasio said on Monday that they expect a “really fast upsurge” that will last a few weeks, and so far cases have appeared to be mild.
Early surge signs in California
California officials have been watching the unfolding situation in New York and bracing for a similar crisis. California has a similar rate of first vaccine doses administered as New York but is slightly behind it on the percentage of people who are fully vaccinated.
Even in the state’s most highly vaccinated pockets, like the Bay Area, infection cases are now clearly on the rise.
The case rate in San Francisco doubled over five days last week, putting the city on a steeper trajectory than the summer delta wave. “This looks just like the South African curve, it looks just like the New York curve,” said Dr. Grant Colfax, director of the San Francisco Department of Public Health.
“We’re watching New York really carefully. They are probably a week or two in the surge ahead of us,” Colfax said.
“It’s just as in March 2020, when we were watching very carefully what was unfolding in Italy and predicting we were just two weeks behind,” said Dr. Sara Cody, Santa Clara County health officer. “We’re watching how quickly omicron rips through the population, even a highly vaccinated population.”
There are signs that if a big surge does come, it will play out quickly.
Chin-Hong said data showing cases doubling every two to three days could mean “it will have infected everyone that it will infect in short order, and there will be no more susceptible hosts.”
“That is why surges end eventually,” he explained. “That will likely be the case in the Bay Area and California as well. We may have to fasten our seat belts, but the ride should be over in a matter of weeks. This should not be a prolonged surge.”
What could be different here
One difference to how omicron spreads here could simply be that New York’s surge has sent out a warning signal, allowing time for preparation.
“We can be proactive rather than reactive, as in the U.K. and in New York,” Chin-Hong said. “It’s like preparing for the storm by getting the food and flashlights ready, rather than fixing the roof when the hurricane is here. But this variant moves so quickly we won’t have much time.”
UCSF infectious disease expert George Rutherford said California’s preemptive statewide indoor mask mandate, reinstated after a moderate rise in cases, also may help.
And California is a large, diverse state with different transmission patterns and vaccine rates throughout the state, so omicron’s impact will really depend on where you live, he said.
Marin County Public Health Officer Dr. Matt Willis emphasized that there also are “reassuring hints” in the data coming out of New York. “While their case rates are surging, so far hospitals are not overwhelmed.”