New COVID-19 Strain Emerging in the Bay Area
A recent report indicates that a new strain of COVID-19 is now responsible for most infections in the Bay Area, coinciding with the start of the school year. This information comes from research conducted at Stanford.
The XFG “Stratus” variant is particularly prevalent in parts of San Francisco, Sacramento, and San Jose. Findings from the Stanford WastewaterSCAN program, which analyzes COVID-19 levels through wastewater samples, show that this strain accounts for more than half of the variants detected in three out of four monitored locations.
Amanda Bidwell, the scientific program manager for WastewaterSCAN, noted that XFG has consistently been the leading variant since July 2025. The data from mid-August highlights its dominance, showing XFG constituted about 82% of the variants, while another variant, NB.1.8.1 (also known as Nimbus), was only around 5.2%.
Dr. Peter Chin-Hong, an infectious disease expert at UCSF, mentioned that Stratus resembles earlier COVID strains like Nimbus. In particular, it has been linked to severe throat symptoms described as a “razor-blade” sore throat. He pointed out that there seems to be an increase in sore throats, especially among older individuals who were not vaccinated last year.
Chin-Hong stated that Stratus presents a broader range of symptoms, including congestion and gastrointestinal issues, although the majority of cases remain mild. Importantly, this variant appears to be more contagious. He predicts that with the return of children to school, even minor sniffles may turn out to be COVID-19.
Dr. Eric Ball, a pediatrician based in Orange County, expressed concern over the timing of this new surge amid an unclear and complicated vaccine distribution process. He emphasized the confusion stemming from mixed messages from government bodies and insurance companies related to the vaccine guidelines.
On Wednesday, U.S. Health and Human Services Secretary Robert F. Kennedy Jr. announced that the FDA has approved updated COVID-19 vaccines with specific restrictions. Vaccines from Moderna are available for children as young as 6 months, while Pfizer is authorized for those 5 years and older, and Novavax is available for patients aged 12 and upward but only for high-risk individuals. Parents are advised to consult with their healthcare providers for eligibility, complicating the situation further.
Adults over 65 can receive the vaccines without any restrictions.
The CDC’s advisory panel is expected to convene soon to discuss recommendations for the updated COVID-19 vaccinations. This marks a shift from earlier policies; in a video released in May, Kennedy stated that the CDC would no longer advocate for COVID-19 vaccinations for healthy children or pregnant women. In contrast, the American College of Obstetricians and Gynecologists has recommended vaccination during pregnancy, and the American Academy of Pediatrics continues to advocate for immunizing infants over 6 months and children against COVID-19.
Dr. Ball raised concerns that children under 2 years old may face significant risks if they are not vaccinated, as they have the highest hospitalization rates among Americans, akin to the rates seen in individuals aged 65 and older. He noted that this age group is not included in the new guidelines.
Additionally, Ball highlighted concerns over a potentially unequal access system, which could widen existing disparities in healthcare. He referenced a federally funded program providing routine vaccinations for children on Medicaid, which typically adheres to CDC guidelines. Given that over half of kids in California rely on Medicaid for vaccinations, they might lose access this year, exacerbating socioeconomic inequalities.
Despite these challenges, both doctors encourage parents to seek advice from trusted health professionals regarding vaccinations. Ball reiterated that families wanting to vaccinate their children should have that option after discussions with their doctors.
Chin-Hong concluded by noting that while the vaccination rollout has been somewhat chaotic, the introduction of a new vaccine this year offers some reassurance, and those who need it most are likely to receive it.
