Over the past month, hospitalizations jumped by nearly 81%, rising from a daily average of 186 admissions to 336, according to state health department data published Friday. The state’s test positivity rate is also up to 13.2% from 6.3% in July. Wastewater samples from Bay Area sewer sheds show the concentration of SARS-CoV-2 virus more than doubling in the same span, underscoring a steady upward trajectory.
The role of new variants
A handful of new COVID-19 variants that have recently emerged may be partially responsible for the current uptick.
The subvariant EG.5 now makes up the largest share of genomic samples nationwide, driving 20.6% of infections over the past two weeks, followed closely by FL.1.5.1 at 13.3%. In California, EG.5 was sequenced in 22.8% of cases, while XBB.1.9.2 was detected in 19%, according to the most recent data on variants.
“Similar to all variants that have arisen, there is some extra degree of immune evasiveness because of a slight difference in genotype,” said Scott Roberts, a Yale Medicine infectious diseases specialist, in a recent briefing.
While only a handful of cases have been logged globally, health officials are also closely monitoring the highly mutated BA.2.86 coronavirus variant in particular because it is believed to have 35 mutations to its spike protein.
“It’s actually shown a pretty insane amount of change all at once,” Katelyn Jetelina, an epidemiologist who consults with the CDC, told NPR. “This is as big of an evolutionary jump as the Wuhan strain to omicron.”
A risk assessment report issued by the CDC acknowledges that BA.2.86 might lead to infections in vaccinated individuals. The severity of the disease it causes and the efficacy of the new booster in combatting it remains uncertain.
Caution on boosters
Despite these escalating figures, officials from the Centers for Disease Control suggest waiting to get a booster. An updated shot, tailored to combat newer variants of the virus currently in circulation, is expected next month.
“If you do get the current COVID-19 vaccine now, or in early September, it could delay your ability to get this updated vaccine that’s coming out in the middle of September,” CDC Director Dr. Mandy Cohen said Friday.
The agency’s guidance recommends a minimum two-month gap between COVID-19 boosters to manage the risk of rare side effects and enhance immune response.
CDC advisers are slated to discuss the rollout of the redesigned COVID-19 shots, aimed at protecting against the XBB.1.5 variant dominant earlier this year, in a meeting scheduled for Sept. 12.
So far, vaccine manufacturers Pfizer, Moderna and Novavax have said that their updated vaccines will be effective in reducing the chances of infection and severe illness against newer strains of the virus common in 2023.
“The new booster this fall won’t be the last,” Roberts said. “COVID-19 will probably be similar to the flu, where the strain mutates slightly every year, and we develop a vaccine before we know exactly which variants will be circulating several months out. It’s always an educated guess based on what’s around at the time.”
Hospitalizations and deaths swell nationwide
The local metrics align with a broader nationwide swell. COVID hospitalizations escalated by 87% in the month ending Aug. 18, with over 2,152 daily admissions, according to the most recent data from the CDC. Deaths attributed to COVID-19 rose 70% compared to the previous month.
The impact on children has been particularly noteworthy, with a spike in emergency room visits throughout the U.S. COVID rates in children ages 11 and under rose to 3.24% through August 25, and adolescents aged 12 to 15 years reached 2.94%, surpassing all other age groups.
“These summer COVID-19 spikes have occurred for the past three years, most likely because more people are traveling,” said Roberts.
The CDC projects that the increase in COVID-19 hospitalizations will persist through the fall. Currently, over 10 million Americans live in communities categorized as “medium” COVID-19 risk levels, warranting masking and other precautions for the most vulnerable individuals.
Mitigation measures unlikely
Though these figures remain significantly lower than previous peaks, their rapid acceleration has caused some familiar disruptions.
Several hospitals, including Kaiser Permanente Santa Rosa Medical Center in the Bay Area, and schools nationwide — particularly in the South — have reinstated mask requirements and other measures to curb the transmission of new infections.
However, this resurgence is highly unlikely to lead to widespread mask mandates or other government-imposed restrictions. Public health authorities now advocate for individuals to assess their own risks as COVID-19 becomes an endemic virus.
“Eliminating it is not possible,” Leana Wen, a professor of public health at George Washington University, told the Associated Press. “And so having measures that are aimed at a societal level, containment is not practical and won’t achieve the aim that we initially thought was possible in early 2020.”
Reach Aidin Vaziri: [email protected]
