The newest noteworthy omicron subvariant, called BA.2.75 (and unofficially nicknamed “Centaurus”), has already turned up in the Bay Area and in spots all over the globe. It appears to have a large number of mutations that could make it more infectious and help it evade prior immunity. Meanwhile, whatever happened to sterilizing surfaces? Here’s the lowdown on whether that matters anymore. Probably much more important is improving indoor air circulation, which a growing number of scientists are pushing to help battle the coronavirus.
New COVID variants mean ventilation is more important than ever
As coronavirus variants like BA.5 and BA.2.75 become more prevalent and more infectious, experts are repeatedly pointing to a transmission reduction strategy that has worked since the beginning of the pandemic — improved air circulation, especially indoors. But what does good ventilation actually look like? It’s about cleaning the air that’s there and getting fresh air in. Read more about how commercial and residential buildings are upgrading their HVAC systems to help fight against spreading the coronavirus — and other future airborne pathogens.
FDA authorizes fourth COVID vaccine, protein-based Novavax
The U.S. Food and Drug Administration on Wednesday granted an emergency use authorization to the Novavax vaccine for COVID, making it the fourth vaccine product now available to American adults. The vaccine, given in two doses delivered three weeks apart, is authorized for people 18 years and older. Studies found the vaccine about 90% effective across all age groups at preventing mild, moderate or severe illness; it was about 78% effective for adults 65 and older. Side effects were similar to other COVID vaccines and included injection site pain, fatigue, muscle aches and headaches. The vaccine works differently from the mRNA products that are most commonly used in the U.S. Novavax prompts antibody development using manufactured coronavirus spike proteins, combined with an adjuvant that boosts the immune response.
Walgreens COVID lab test-positive rate hits an all time high at 51.6%
More than half the laboratory PCR coronavirus tests taken at Walgreens stores in California are coming back positive, according to updated data from the retail chain. The state’s average COVID-19 positivity rate reached 51.6% this week, topping the previous peak of 43.5% recorded in January during the winter omicron surge. The positive test rate for the U.S. as a whole is 41.6% at the chain’s pharmacies, up from 32.7% the prior week. PCR tests are the gold standard for virus detection, because they are more sensitive than at-home rapid antigen tests and correctly identify more asymptomatic infections. They may also be better at identifying newer virus sub-variants such as BA.4 and BA.5, which are taking longer to appear in at-home rapid antigen tests. Many people who seek PCR tests at Walgreens may have already tested positive using a home kit and are seeking confirmation from a more reliable source.
Contra Costa County officials note “significant rise” in COVID cases
Highly contagious omicron subvariants are keeping COVID-19 case counts high in one of the Bay Area’s most populous counties, health officials said Tuesday. “We’ve seen a significant rise in transmission of COVD-19,” Anna Roth, the health director for Contra Costa County, told supervisors on Tuesday. The county is averaging 41 cases per 100,000 residents, a figure that has remained stubbornly high over the past two months. “This is due to the new variants BA.4 and BA.5,” she added, which are “much more contagious variants.” Hospitalizations and admissions to intensive care unit beds in the county are holding steady despite the high case tally, which may help offer a better overview of the pandemic since so many people now depend on rapid at-home tests with results that are not reported. As of Tuesday, there were 100 people hospitalized with COVID-19 in Contra Costa County, another figure that has changed little since dropping in April. “We still strongly recommend masking indoors,” she said. “It’s not an order. It’s a strong recommendation.”
California COVID hospitalizations projected to peak in late July
COVID hospitalizations statewide, which have been gradually increasing the last several weeks, appear poised to peak toward the end of July at roughly 4,000 to 4,500 people, California state epidemiologist Dr. Erica Pan said Tuesday, citing state modeling projections. Those are considered “manageable levels of COVID hospitalizations” and are considerably lower than hospitalization levels during previous surges, Pan said during a virtual update on COVID and monkeypox. “I’m really glad a lot of our tools, especially vaccines, are working,” she said. About half of hospitalizations may be incidental, meaning people were hospitalized with COVID, not for COVID — they went in for something else and tested positive while there. Such cases still require hospital infection control measures. Statewide, deaths continue to trend downward. “We have seen very low levels of deaths so vaccination and immunity is holding up in California,” Pan said.
Can the BA.2.75 COVID variant spreading in the Bay Area evade immunity?
The omicron coronavirus strain continues to spawn highly infectious subvariants, and the latest one gaining ground, known as BA.2.75, has already shown up in the Bay Area. While BA.5 is currently the dominant subvariant worldwide, BA.2.75 has turned up in at least a dozen countries since it was first detected in May in India, where it is driving a new surge. Here’s what we know so far about BA.2.75.
BA.4 and BA.5 can shrink reinfection window to 28 days, data show
The omicron subvariants BA.4 and BA.5 can substantially shorten the period of immunity between COVID-19 infections, according to new research from health officials in Australia. The nation’s health department said in a bulletin last week that the new strains are so immune-evasive that reinfections are occurring less than a month after recovery from a previous COVID-19 infection. “People who test positive to COVID-19 more than 28 days after ending isolation due to previous infection should be reported and managed as new cases,” the national health agency said. “I think this is a wake-up call for all of us,” Dr. George Rutherford, an infectious disease expert with UCSF said regarding the new data in an interview with KGO-TV. “This means your period of immunologic protection following infection is probably shorter. We previously thought it was around three to four months. It’s probably less.”
