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The bay area omicron wave is underway. Here’s what to expect in the coming weeks

The omicron outbreak has started in the Bay Area, but this fifth wave of COVID is unlikely to unfold like any of the previous – and now very familiar – roller coaster models of the 2-year pandemic.

Health experts predict a staggering rise in cases in the days and weeks to come, likely far exceeding the summer swells in the Delta and possibly last winter as well. Cases will likely increase and collapse faster than previous waves, perhaps within weeks rather than months.

While many more people are expected to get sick, including those who are vaccinated and boosted, their symptoms are expected to be mostly mild and the pressure on local hospitals is not expected to be as intense as it was a year ago.

Still, health officials are bracing for a deluge of demand for testing and treatment for COVID. And they are bracing for a potentially alarming number of people all feeling sick at the same time – a scenario that could cause brief but problematic interruptions to services, from health care and education to transportation and transportation. grocery store.

“People have to recognize that with omicron we will see a lot more transmission in our community. There will be a lot more infections, ”said Dr. Matt Willis, Marin County health official.

Willis recorded what could be the region’s first major omicron outbreak a week ago: more than half of the roughly 60 people who attended a holiday party later tested positive for the coronavirus, although everyone has been vaccinated and many of them have been stimulated. None suffered from serious illness.

But this event, he said, probably foreshadowed the weeks to come. “We are deeply in the transition from the delta to the omicron,” said Willis.

Less than three weeks after the first case of omicron was identified in the United States – in a San Francisco resident on December 1 – the highly infectious variant was dominant nationwide.

Nationwide, coronavirus cases have already passed the peak of the delta surge, even before an expected increase due to Christmas and other holiday gatherings. In other countries where omicron has overtaken the United States, cases have quickly eclipsed all previous waves of the pandemic.

Parts of the United States are already inundated. People have reported queuing for two or three hours for coronavirus tests in some towns on the east coast where cases are increasing faster than at any time during the pandemic. In the Bay Area, home test kits were nearly impossible to find in stores before the holidays, and counties were reporting a growing demand for lab tests.

Cases were rapidly doubling in San Francisco a few days before Christmas. Health officials in the region have said they expect the holiday meetings to further accelerate the meteoric spread of omicron.

Experts said it was encouraging that South Africa, the first country to be flooded by omicron in mid-November, is already seeing a drop in the number of cases, suggesting its latest wave is s fades almost as quickly as it started.

The key question from a public health perspective is whether an explosion of cases will manifest itself in hospitalizations and deaths.

“We always expected the cases to increase in the winter,” said Dr Nicholas Moss, Alameda County health official. But he and his colleagues were counting on delta this winter and a scenario similar to the summer outbreak – increasing cases but not necessarily an alarming jump in hospitalizations. “Omicron is going to spread so widely that it will do a very good job of reaching vulnerable people,” Moss said.

Evidence increasingly suggests that omicron causes less severe disease than delta or other variants of the coronavirus, possibly due to widespread immunity from vaccination or previous infection. Studies in South Africa and the UK report 40-70% fewer hospitalizations with omicron compared to delta. Another potential bulwark against hospitalizations: U.S. officials have cleared two new pills to treat early COVIDs and prevent serious illness, though it’s unclear how widely these treatments will be available during the omicron outbreak.

Communities with high vaccination rates – including the Bay Area, where in many counties more than 80% of residents are vaccinated – will likely see only a small fraction of those infected become seriously ill.

But health officials have repeatedly warned that even if a much lower proportion of those infected end up seriously ill and hospitalized, a massive increase in cases could still result in enough patients with severe COVID to overwhelm health systems.

“Because it’s so infectious, even though omicron is half the severity of delta, we could end up with our hospitals overloaded,” said Dr Maya Petersen, UC Berkeley epidemiologist who modeled them. illnesses in California during the pandemic.

Boosters will be essential, officials said. Data from around the world shows that two doses of the Pfizer and Moderna vaccines may not offer much protection against serious illnesses caused by omicron, and even a booster won’t prevent many people from getting sick with mild symptoms. Studies show that vaccine protection against symptomatic illnesses caused by omicron drops to 5% just six months after a second dose, but rises to around 50% with a booster.

Notably, a third shot appears to boost protection against serious illness and hospitalization of omicron to over 90%. The problem is, not many people get a boost, even in the Bay Area. In particular, some healthcare workers suffered their first round of shooting almost a year ago, meaning their protection has likely declined significantly.

Last week, Gov. Gavin Newsom announced that all California health workers will need to be reminded by February 1. Some infectious disease experts have called for redefining “fully vaccinated” as three doses of Pfizer or Moderna vaccines or two doses of vaccines. Johnson & Johnson.

In California, about 40% of people eligible for the boosters – which include anyone who has received the Johnson & Johnson vaccine and those who are at least six months away from their second dose of Pfizer or Moderna vaccines – have received them.

Rates are a bit higher in parts of the Bay Area, including San Francisco, where about 53% of eligible people received boosters. But even that is not enough, say health officials.

In San Francisco, if the booster intake does not accelerate over the next few weeks, hospitalizations for COVID could approach or even exceed last winter’s peaks, even though omicron typically causes less severe illness than delta, according to a model developed by Petersen. If the use of the booster doubles over the next few weeks, the outlook is much brighter – hospitalizations could be less than half of last winter.

Just before Christmas, 37 people were hospitalized with COVID in San Francisco. Hospitalizations peaked in the city’s pandemic last winter, with 259 patients on January 12.

“With each passing day and more people being boosted, you are in better shape,” said Petersen, noting that the boosters may start to take effect a few days after firing.

Even if hospitalizations increase a bit in the coming weeks, the Bay Area is very likely to withstand the omicron surge without too much stress on local health systems.

But the rest of California is a bit of a concern, especially the parts of the Central Valley that have lower vaccination and booster rates. And if the entire state is slammed by omicron at the same time, overwhelmed health systems in one region can put pressure on neighboring communities.

Hospitals in Stockton, Modesto or Fresno that lack intensive care beds may need to transfer patients to the Bay Area – a situation that has occurred in previous increases. Petersen’s COVID model predicts that San Joaquin County hospitals will likely reach or exceed last winter’s peaks, even if booster usage increases dramatically there.

And there are other questions about omicron that could influence how this push unfolds. The highly mutated variant is still so new that much remains unclear about its effects, especially in the longer term, infectious disease experts have said.

Critical variables include the ease with which omicron spreads among children, especially after they return to school after the holidays. A few large universities have said they will delay returning to in-person classes after the holidays in light of the spread of omicron, but in California, public schools are expected to resume classes as usual in early January.

It is also unclear how vulnerable vaccinated and stimulated people might be to a lengthy COVID if they were infected with omicron. And it remains to be seen how long the boosters provide protection – Israel has already started giving fourth injections to some of its vulnerable populations.

“We need to let the data evolve and have a much better idea of ​​how it’s going, not just globally and in the United States, but locally where we have high vaccination rates,” said Dr George Rutherford, an infectious disease of UCSF. expert. “Right now, the advice is valid: you don’t want to get infected with this virus. “

Erin Allday is a writer for the San Francisco Chronicle. Email: [email protected] Twitter: @erinallday