Despite the emergence of numerous variants and relaxed restrictions, some infectious disease experts at Stanford remain optimistic that the ongoing vaccine rollout will be enough to fend off a fourth COVID-19 surge in California. Others, though, are taking a more cautious stance because case numbers in California are still relatively high and the efficacy of vaccines is unknown against some variants.

“The news is overall good,” said Jake Scott, an infectious disease specialist at Stanford Medicine. “But I’ve always seen the variants as a warning sign from Mother Nature basically telling us, hey, you still need to take this seriously.”

His views are in line, for the most part, with other experts like chief medical advisor to the President, Anthony Fauci, and Scott Gottlieb, former Food and Drug Administration (FDA) commissioner. They believe that while Europe’s current surge should serve as a warning sign, and public health measures like masking and social distancing should still be observed, the United States is in a different position because of a more successful vaccination campaign. There is, however, always a risk of another surge, particularly if states roll back public health restrictions, which some have started doing. 

A positive sign when it comes to a fourth wave, experts say, is a decline in cases in the state of California. Despite the emergence of multiple variants, California’s seven-day average for new cases is just under 3,200, well below the peak of around 44,000 in mid-December and early January. The 7-day average of COVID-19 patients in hospitals is also down substantially: the current average is around 3,800, down from over 22,600 at its peak.

Philip Grant, an infectious diseases assistant professor and the principal investigator of Stanford’s Johnson & Johnson’s vaccine clinical trial site, said he believes less activity and increased immunity, partially due to the vaccine, have contributed to the dramatic decrease in cases. 

But if cases have leveled off, a fourth surge could still be in the cards. Dean Winslow and Catherine Blish, both infectious diseases professors, took a less optimistic approach. Winslow acknowledged that though cases and hospitalizations have fallen, “many of us are concerned that the curve appears to have leveled off in the past week,” as case numbers are flattening in the 3,000 range.

“It is impossible to predict [another surge] because it depends on human behavior, our ability to deliver vaccines, and possibly the emergence of new variants,” Blish wrote in a statement to The Daily.

There are multiple factors that could affect case numbers going forward, experts said. While the vaccine rollout is accelerating in the state, new variants and loosened restrictions could put positive pressure on the curve.

As of Tuesday, 21% of California had received at least one vaccine shot and 10.1% of the state is fully vaccinated, according to the New York Times vaccine tracker. Increased distribution of the one-shot Johnson & Johnson vaccine, which was approved by the FDA for emergency use on Feb. 27, may also speed up vaccination rates, according to Grant.

Vaccines could help keep prioritized groups out of the hospital or from developing severe disease, which could mitigate the impacts of an uptick in cases. One of the largest impacts of the vaccines thus far has been on nursing home residents, according to Scott.

“This is far and away the longest stretch I’ve gone in the hospital without seeing a nursing home resident admitted for COVID-19, which is incredible,” he said.

Older adults are at a higher risk for developing severe cases of COVID-19 and requiring hospitalization, as 80% of virus deaths in the U.S. have been in adults 65 and older. Vaccinating nursing home residents and older adults will blunt the number of hospitalizations and deaths, making it less likely that hospitals will be overrun — the main concern with surges — in the event of a fourth wave.

However, now that many nursing home residents have been vaccinated, Blish and Scott highlighted the need to start targeting other high-risk groups like essential workers.

“Now I’m seeing a ton of patients who are Latinx, oftentimes in their 40s, 50s, 60s,” Scott said. “These are essential workers who don’t have the privilege of being able to social distance. And some of them have very severe illnesses … I can’t emphasize enough how important it is to really prioritize vaccination for these people who are being hospitalized.”

Essential workers like grocery store employees, correctional institute workers and food production and processing employees have been hit hard by the virus because many of them work in close proximity without adequate testing and now vaccine resources. Close working and living quarters are breeding grounds for the virus, so until those people are vaccinated, the risk of contracting and spreading the virus among themselves and the community remains high. 

But variants could threaten the progress made by the state’s vaccination campaign. The three variants that are causing the most concern are the U.K variant (B.1.1.7), the South Africa variant (B.1.351) and the Brazil variant (P.1). All three variants have been found in California and may be more transmissible, deadly or resistant to vaccines.

However, Grant and Scott said it is normal to see numerous variants and do not see their presence harming the progress of fighting against COVID-19.

Grant said the number of cases that had been identified in Santa Clara County caused by the British and South African variants was low enough that “I don’t see how that would get to a point where we’d have another surge.”

“The good news is that our three currently available vaccines, while perhaps not quite as effective against some of these new variants, appear to provide at least partial protection, especially against severe disease,” Winslow added.

While the Moderna and Pfizer vaccines both showed efficacies around 95% in preventing infection after two doses, neither has been tested with any of the three variants that have emerged. Johnson & Johnson’s vaccine, however, was in clinical trial stages as variants emerged and has been tested in South Africa under the B.1.351 variant. Regardless of test location, the company’s vaccine proved to be 85% effective at preventing severe disease. 

Winslow also wrote that vaccine companies are currently working on a version of the vaccine that is modified specifically for the variants. They “will likely be released later this year and will be given as a single-shot ‘booster’ to individuals who have been immunized,” according to Winslow.

A recent lab study showed that the Pfizer and Moderna vaccines may be up to 10% less effective against the South African variant, but their usage of mRNA technology provides hope that they can be tweaked to provide more protection against the variants.

“One great thing about the mRNA vaccine technology in general is that it’s adaptable, it’s nimble, so the vaccines can hopefully be quickly modified to account for these various mutations,” Scott added.

And while vaccines may need to be modified, Grant said he predicts that the pace of vaccination will be able to keep up with the spread of variants. 

In terms of whether another surge is expected, Scott said he is optimistic that there are enough defenses against the virus, with the vaccines being at the forefront. Although case numbers may level off for a while, he predicts that there will not be any more large surges. 

“I’m especially confident in the Bay Area in particular — the Bay Area did a phenomenal job last spring at flattening the curve,” he said. “I think that as long as we continue to stay the course, and don’t let our guard down too much, I think that we’ll get through this without another big surge.”