SAN FRANCISCO, Calif. (KRON) — The pandemic has crashed over the country like ocean waves. Cases surge and then recede. COVID researchers are taking lessons learned from the Delta variant to forecast if and when the next big wave will hit the Bay Area.
This summer a fourth wave swept through unvaccinated populations because of the highly infectious Delta variant. Without knowing COVID mutations like Delta could “breakthrough” vaccinations, hopes were high that the pandemic was finally coming to an end.
UC San Francisco infectious disease expert Dr. Peter Chin-Hong said Americans jumped into the summer with “wild abandon.”
Like ocean waves generated from distant storms, the COVID-19 virus and its mutations travel across oceans and borders.
“First identified in India in December 2020, Delta swept rapidly through that country and Great Britain before reaching the U.S., where it quickly surged. It is now the predominant SARS CoV-2 variant, accounting for more than 99% of COVID-19 cases and leading to an overwhelming increase in hospitalizations in some states,” Yale Medicine researchers wrote in a recently updated study.
The Delta variant proved once again the throwing caution to the wind comes with consequences and washed away chances of communities achieving “herd immunity.”
Chin-Hong said, “If we look back to what happened with Delta in the Bay Area, we actually saw it coming. It was happening in India. We were celebrating our vaccinates rates and they were not high enough for something new. We probably thought we were immune, but we weren’t.”
By October, case rates and hospitalizations dropped back down in the Bay Area. But the holidays are right around the corner.
Last holiday season was a disaster from a public health perspective. San Francisco had a huge spike in COVID case rates, hospitalizations, and deaths in December of 2020. Still, experts are cautiously optimistic that California will experience a period of calm lasting into the winter with case rates staying low.
Chin-Hong said the virus is unpredictable, and with travel restrictions from Europe easing, we have to remain flexible. There are thousands of different types of COVID circulating across the world.
One new COVID variant that health officials are currently monitoring closely is a sub-lineage of Delta named AY.4.2.
“In the U.K. it was zero of their cases just a few weeks ago, and now it’s seven percent. We don’t really know what it means. It doesn’t really look to have any scary mutations,” Chin-Hong said.
He added, “It’s something we have to watch particularly as travel from Europe opens back up to the U.S. What we see in other parts of the world may come here sooner rather than later.”
Vaccines remain the strongest defense against new COVID mutations from spreading into the next big wave.
Yale Medicine researchers wrote, “People who are not vaccinated are most at risk, and the highest spread of cases and severe outcomes are happening in places with low vaccination rates.”