A newly dominant strain of COVID-19, called “Stratus COVID-19 Variant ,” is fueling a surge in infections across the Bay Area and straining healthcare providers as schools reopen, according to Stanford University researchers. Doctors warn the highly transmissible variant is increasing patient visits and hospitalizations, while questions remain about how vaccines will be distributed to those who need them most.

Stratus COVID-19 Variant Becomes the Predominant Strain

The XFG “Stratus COVID-19 Variant ” strain has overtaken other variants in San Francisco, Sacramento, and San Jose, wastewater monitoring data shows. The Stanford WastewaterSCAN program, which tracks COVID-19 through sewage samples, reported that Stratus COVID-19 Variant now accounts for more than 80% of infections in some sites, far outpacing other variants.

“We have routinely seen XFG as the predominant variant since July 2025,” said Amanda Bidwell, scientific program manager for WastewaterSCAN.

Dr. Peter Chin-Hong, infectious disease expert at UCSF, explained that the strain is spreading efficiently and showing slightly broader symptoms than past lineages. “There’s a little bit more sore throats with some people,” he said. “Particularly in those who are older, who didn’t get vaccinated last year.” Other reported symptoms include congestion and gastrointestinal issues, though most cases remain mild.

Still, Chin-Hong emphasized that the strain’s contagiousness is concerning. “It’s more transmissible, so we expect a lot of people will get it. Particularly with kids going back to school, a sniffle is likely going to be COVID.”

Pressure on Healthcare Providers

The Stratus COVID-19 Variant wave is arriving at a difficult time for healthcare systems already balancing summer illness trends and the return of in-person classes. Clinics and hospitals are reporting rising patient volumes, especially among children and older adults.

Dr. Eric Ball, a pediatrician in Orange County, said providers are already feeling the strain. “We’re seeing more kids coming in with COVID-like symptoms just as school is starting,” he said. “The challenge is distinguishing Stratus from other seasonal viruses while ensuring families get the care and advice they need.”

Hospitalization numbers remain below previous pandemic peaks, but doctors caution that younger children and seniors are more likely to require care. “Kids from 6 months old to 2 years old continue to be among the most vulnerable,” Ball noted. “Their hospitalization rates are comparable to those of people over 65.”

Vaccination Access and Concerns

Updated vaccines tailored to newer variants are becoming available, but access remains a challenge for families. Providers say rollout details are causing confusion, particularly around who is eligible and how the vaccines will be distributed.

Ball warned that limited access could exacerbate existing inequities. “In California, over 50% of kids are on Medicaid, and they often receive their vaccines through federally funded programs,” he said. “If updated COVID-19 vaccines are not included in routine programs, many children might be left out. We already see disparities in healthcare, and this could make them worse.”

Doctors are urging families to consult directly with pediatricians and primary care providers for guidance. “Any family who wants to vaccinate their child after conversations with their doctor should have the opportunity,” Ball said.

Outlook for the Fall

While the spread of Stratus COVID-19 Variant raises concerns, experts say there is reassurance in the tools now available. Testing remains widely accessible, and vaccines designed to address recent variants are expected to provide protection against severe illness.

“We will have a new vaccine this year, and the people who need it the most are going to get it,” Chin-Hong said.

Healthcare providers agree that vigilance will be essential as schools resume and the fall respiratory season approaches. Families are encouraged to monitor symptoms, seek medical advice when necessary, and stay up to date on vaccinations.

Also Read :- XFG ‘Stratus’: The Rising COVID Variant Being Closely Watched by WHO