The highly contagious Delta is now the dominant variant of coronavirus in both California and throughout the United States, affecting areas with low vaccination rates, especially harsh ones, and raises concerns about what comes next in a pandemic that has progressed well. over a year.
The news came Thursday when Pfizer reported new evidence that its COVID vaccine was less effective after six months and said it plans to ask the U.S. Federal Drug Administration to approve a booster shot.
In California, the Delta variant accounted for nearly 43% of cases analyzed by the state in June ahead of the 30.6% of cases linked to the next most common strain, the UK or Alpha variant, according to the California Department of Public Health. In May, Delta accounted for only 5.8% of analyzed cases in California.
Across the United States as a whole, according to the Centers for Disease Control and Prevention, the Delta variant now accounts for 51
“We see these varieties compete with each other for survival,” said John Swartzberg, an infectious disease expert and professor emeritus at UC Berkeley. “Internecine warfare, and Delta clearly survives.”
Health experts have warned that the strain, which was originally found in India, is more contagious than others and is likely to increase the chance of hospitalization. And while the vaccines have proven to be extremely effective in preventing hospitalization and serious illness, even when it comes to Delta, the strain appears to be somewhat more vaccine-resistant than its predecessors.
New data from Israel showed the effectiveness of Pfizer’s two-dose vaccine in humans vaccinated in January or February dipped to 64% to prevent infection and symptomatic disease.
But the unvaccinated are really at risk, officials warned Thursday at a White House briefing.
“Nearly all COVID-19 admissions and deaths in the United States now occur among unvaccinated individuals,” said Jeff Zients, COVID-19 Response Coordinator at the White House.
Sixty percent of Californians 12 years and older are now fully vaccinated, with a further 9.4% partially vaccinated. A study published Thursday in Nature showed that while people who are fully vaccinated are well protected, people with only one dose are still at risk.
This risk varies from place to place. Across the bay, vaccination rates are high and the number of new cases remains low, meaning that even people who have not yet been vaccinated – such as young children – are at a lower risk because most people around them are inoculated.
“I feel like I’m sitting on this island right now, which is probably the best place to sit in the world,” Swartzberg said of the Bay Area. “In communities that have lower vaccination rates like Central Valley or Northern California, those are the areas that will still have more problems with Delta.”
But vulnerable populations in the Bay Area are not immune. An outbreak of the Delta variant in a homeless shelter in Santa Rosa has infected at least 27 residents in shelters, with dozens of tests still outstanding. The city said in a statement that the majority had not been vaccinated.
A recent outbreak of the virus at the state capital of Sacramento among nine people, including four who were fully vaccinated, combined with growing concern about the Delta variant, prompted officials to order all lawmakers and staff to wear masks regardless of their vaccination status. In late June, public health workers in the Los Angeles County Delta cited the variant when they even asked vaccinated people to continue wearing masks in restaurants, grocery stores and other indoor locations.
To continue spreading, viruses are constantly mutating, and California now tracks six “variants of interest” and four more worrying “variants of concern.”
The state’s first known dominant variant – B.1.427 and B.1.429 strains known as Epsilon – was first detected in California. It was taken over in March by the more portable Alpha variant (B.1.1.7) from the UK, which made room for Delta (B.1.617.2) last month.
“Delta will eventually be replaced with something else if we do not do something different,” Swartzberg said. “This is the record that keeps playing over and over again, and the only way to stop this is to get enough people vaccinated so the virus can’t find people to multiply in.”
Yet infectious experts say it is important not to panic and be aware of new cases. While fully vaccinated people may become infected, only a few will be symptomatic and a small fraction will require some form of professional medical attention.
“Let’s be very clear,” Monica Gandhi, an infectious disease doctor at UCSF, told Twitter recently, “Delta is not spreading like wildfire across the United States. This strain is spreading in severely unvaccinated regions without natural immunity.”
California is even likely on or approaching flock immunity – an inaccurate marker – among some population sectors, especially among the elderly who were among the first to have access to the vaccines.
According to an analysis by George Lemp, an epidemiologist and former director of the HIV / AIDS research program at the University of California Office of the President, new cases have been reported daily in California among people aged 80 and over, more than tripling during the three years. weeks from 10 – 30 June compared to the end of May and the beginning of June. Most new cases are among people under the age of 35 who are less likely to be vaccinated than seniors.
“These trends show that we are now in herd immunity among people 65 and older in California,” Lemp said, “given the high vaccination rates and the significant cases and deaths observed among these age groups.”