San Antonio Health Flu Season 2026-27
Why Flu Is Hitting San Antonio Weeks Early This Year — and Why a Shot Now Still Beats Thanksgiving Exposure
A mutated H1N1 strain is pushing flu activity up across Texas far sooner than last year. Here is what state and federal data show, who is most at risk and the timing that matters for your family.
By The Texas Health DeskFact-checked against Texas DSHS surveillance reports, CDC FluView and local health reportingUpdated November 13, 2026Scope San Antonio, Bexar County and Texas, 2026-27 flu season
In most years, San Antonio families can treat flu as a January problem. Bexar County usually sees its highest flu rates in January and February, local health officials have said, and last winter’s surge did not take off until December. This fall is different. Pediatricians and urgent care clinics across Texas are reporting more children with flu each day, and doctors say the season started noticeably earlier than last year.
The data back them up. Texas hospital labs reported that 9.43% of flu tests came back positive in the week ending October 17, 2026, according to the Texas Department of State Health Services. A year earlier, in late October 2025, the figure was 1.85%. Nationally, the CDC says early-season activity “is currently higher than typically observed at this time of year.” With Thanksgiving gatherings two weeks away, the timing of a flu shot now carries real weight.
What We Know
- Texas flu test positivity was 9.43% in mid-October, up from 1.85% at a similar point last year.
- H1N1 accounts for 97.7% of subtyped influenza A viruses nationally, the CDC reports.
- Texas was among seven states with moderate to high flu activity as of October 31.
- Texas hospitals report a sharp rise in children with flu and RSV.
What Is Still Unclear
- Exact current Bexar County positivity, which Metro Health and local hospitals update separately.
- Whether an early start means a more severe season.
- How well this year’s vaccine matches the mutated H1N1 strain.
- When the San Antonio season will peak.
Texas Is Running Well Ahead of Last Year
State surveillance shows how quickly the picture changed. In the DSHS report for the week of October 11 to 17, 2026, hospital labs tested 3,414 specimens and 322 were positive for flu, or 9.43%, up from 8.84% the week before. Season to date, 9.09% of tests were positive. Influenza A made up 97.83% of positives, and every subtyped influenza A sample was H1N1. No H3N2 was found.
Texas Flu Test Positivity: This Fall Versus Last Fall
The DSHS report listed Public Health Region 8, which covers San Antonio and surrounding South Texas counties, among six regions reporting increased flu activity. By the end of October, the CDC listed Texas among seven states with moderate to high activity, alongside California, Florida, Louisiana, Oregon, South Carolina and Washington, NBC reported.
Why a Low Clinic Number Can Be Misleading
One measure still looked calm in mid-October. Influenza-like illness, the share of outpatient visits for fever plus cough or sore throat, was 2.43% in Texas, below the state’s 4.65% baseline, and the statewide activity level was rated “minimal.” By the week ending October 31, the CDC’s FluView showed Texas outpatient flu-like illness at 3.7%, rated moderate and rising, according to a summary by Local Health Signal. Lab positivity usually moves first; clinic visits catch up as more people get sick.
Texas Flu-Like Illness Versus the Baseline
The Strain Behind the Early Start
Last winter was dominated by H3N2 subclade K, which drove a severe season across Texas and the country. This fall, a different virus has taken over. The CDC reports that 97.7% of subtyped influenza A viruses at public health labs are H1N1, the strain behind the 2009 swine flu pandemic. The version spreading now belongs to subclade D.3.1.1 and carries a mutation called G155E, first identified in Seattle in September, according to a bioRxiv preprint cited by NBC.
That mutation sits at a spot important for antibody recognition, said Johns Hopkins virologist Andrew Pekosz. “A mismatch is not a black-or-white situation,” he said. “We may have less immunity, not no immunity.” The CDC says it is too early to judge vaccine effectiveness or severity. Historically, H1N1 has hit children and younger adults hard, which may help explain the rise in pediatric visits.
National Flu Indicators, One Week Apart
Clinical lab test positivity, %
Outpatient flu-like illness, %
Hospital admissions per 100,000
Share of emergency visits for flu, %
An Early Start Is Not Automatically a Worse Season
Experts quoted by NBC stressed that early activity does not by itself predict severity. What it does mean is a longer window for transmission, and more overlap with the holiday travel season. The CDC’s forecast for the week ending November 21 projects 6,900 to 30,100 flu hospital admissions nationally, a wide range that reflects uncertainty about how fast the virus will spread.
Who Faces the Highest Risk
Older adults are being hospitalized at the highest rate. In the week ending October 31, the national flu hospital admission rate for adults 65 and older was 7.9 per 100,000, more than three times the overall rate of 2.5, according to CDC data reported by Medical Daily. Young children were close behind adults 50 to 64.
Flu Hospital Admissions by Age, Week Ending Oct. 31
Children deserve special attention this year. Texas Children’s Hospital pediatrician Dr. Natalie Tarrant told Spectrum News the season “definitely started earlier” than last year, and that last season “was worse than the average year for flu.” The CDC counted 199 pediatric flu deaths in the 2025-26 season, and the first pediatric death of 2026-27 was linked to H1N1. Infants younger than 6 months cannot be vaccinated, so they rely on the people around them.
| Who | Risk level | Flu shot | If symptoms start | Get urgent care if |
|---|---|---|---|---|
| Infants under 6 months | High | Too young; vaccinate caregivers and pregnant parent | Call pediatrician right away | Trouble breathing, poor feeding, fewer wet diapers |
| Children 6 months to 4 years | High | Yes; first-timers under 9 need 2 doses 4 weeks apart | Call doctor; antivirals often advised | Fast breathing, bluish lips, fever of 100.4 or higher with lethargy |
| Adults 65 and older | Highest admission rate | Yes; higher-dose options available | Contact doctor within 48 hours | Chest pain, confusion, shortness of breath |
| Pregnant people | Elevated | Yes; also protects newborn | Call provider promptly | Breathing trouble, high fever |
| Asthma, diabetes, heart disease, obesity | Elevated | Yes | Ask about antivirals within 48 hours | Worsening chronic symptoms |
| Healthy teens and adults | Lower | Yes, recommended for all 6 months and older | Rest, fluids, stay home | Symptoms improve then return worse |
Vaccine recommendations and the two-dose rule for young children come from CDC and DSHS guidance; the warning signs listed reflect standard CDC guidance and comments from Cook Children’s Dr. Suzanne Whitworth, who told Spectrum News to “see a doctor if there is any difficulty breathing” and noted that fever in healthy children means 100.4 degrees or higher rectally.
Your Plan for the Next Two Weeks
- Get the flu shot this weekDSHS recommends everyone 6 months and older get vaccinated as soon as possible. Most insurance covers it at no cost at pharmacies and clinics.
- Check young children’s dose countChildren under 9 getting their first flu vaccine need two doses about four weeks apart.
- Know your high-risk contactsGrandparents, infants and anyone with chronic illness at holiday gatherings benefit most from your vaccination.
- Act fast on symptomsCall a doctor within 48 hours for antivirals, especially for high-risk family members.
- Stay home while contagiousDSHS says people are most contagious in the first three days and can return after 24 hours fever-free with improving symptoms.
- Skip the ER for mild casesDSHS says emergency rooms are not needed for mild symptoms; save them for breathing trouble or other warning signs.
Where to Get Vaccinated in San Antonio
San Antonio Metro Health’s immunization clinic at 210 N. Mel Waiters Way offers flu shots by appointment, and University Health has offered walk-in flu shots at several locations in past seasons. Most insurance plans cover flu shots at no cost at pharmacies, primary care offices and clinics. Low- or no-cost options include the Texas Vaccines for Children and Adult Safety Net programs. Check with Metro Health or your provider for current hours and pop-up clinic dates.
How This Season Has Unfolded
- Late Aug. 2026Flu infections begin rising nationally, earlier than usual.
- September 2026Mutated H1N1 subclade D.3.1.1 identified in Seattle.
- Oct. 1, 2026DSHS urges all Texans 6 months and older to get flu shots.
- Week ending Oct. 10First U.S. pediatric flu death of the season, linked to H1N1.
- Oct. 11 to 17Texas flu test positivity reaches 9.43%.
- Week ending Oct. 31U.S. flu admissions rise 38% to 8,396; Texas in moderate to high group.
- Nov. 5, 2026Flu growing or likely growing in 42 states.
- Nov. 10, 2026Texas hospitals report a sharp rise in children with flu and RSV.
- Nov. 21, 2026CDC forecast window: 6,900 to 30,100 weekly admissions.
- Jan. to Feb. 2027Bexar County’s usual flu peak, per local officials.
Looking Back at Last Winter
Last season offers a reminder of how fast flu can move in Bexar County. More than 10% of flu tests at San Antonio-area providers were positive by November 29, 2025, up from below 1% at the start of that month, the San Antonio Report reported. In the week ending December 27, 2025, about 11% of emergency department visits in the county were flu-related, compared with just under 6% a year earlier, Axios reported. This year’s curve appears to be starting sooner.
RSV and COVID Are Circulating Too
Flu is not the only respiratory virus in play. In the same mid-October DSHS report, 3.55% of RSV tests and 2.99% of COVID-19 tests were positive statewide. Spectrum News reported Texas hospitals are seeing a rise in children with RSV as well as flu. Testing helps doctors decide on treatment, since flu antivirals do not work against RSV or COVID.
- Flu shotEveryone 6 months and older
- Protection buildsAbout 2 weeks
- Kids under 9, first time2 doses, 4 weeks apart
- AntiviralsBest within 48 hours
- Most contagiousFirst 3 days
- Back to normal24 hours fever-free
Frequently Asked Questions
Is flu season early in San Antonio this year?
Yes. Texas flu test positivity reached 9.43% in mid-October 2026, compared with 1.85% in late October 2025, and doctors report flu season started earlier than last year.
What flu strain is going around in Texas?
Mostly influenza A H1N1. A mutated version, subclade D.3.1.1, is driving the early rise nationally.
Is it too late to get a flu shot?
No. DSHS recommends getting vaccinated as soon as possible. Protection takes about two weeks to build.
Does this year’s flu vaccine work against the new H1N1 strain?
It is too early to know how well it matches, the CDC says. Experts say a partial mismatch still provides some protection and can reduce severity.
Where can I get a flu shot in San Antonio?
Metro Health’s immunization clinic at 210 N. Mel Waiters Way offers shots by appointment, and pharmacies, clinics and doctor’s offices offer them widely, usually at no cost with insurance.
When should I take my child to the doctor for the flu?
Seek care right away for any difficulty breathing, and call a doctor for high fever, dehydration or a child who is not acting right.
How long is the flu contagious?
People are most contagious in the first three days of illness. DSHS says return to normal activities after 24 hours without fever and improving symptoms.
When does flu season usually peak in San Antonio?
Bexar County typically sees its highest flu rates in January and February, though this season started earlier than usual.
The Short Version
Flu is rising early in San Antonio and across Texas, driven by a mutated H1N1 strain. Texas flu test positivity reached 9.43% in mid-October, about five times the level at a similar point last year, and Texas is among seven states with moderate to high activity. Adults 65 and older have the highest hospitalization rate, and Texas hospitals are seeing more children with flu. A shot takes about two weeks to work, so get one now. Call a doctor within 48 hours of symptoms for high-risk family members.
Omisha is a health writer passionate about turning complex medical research into clear, actionable content readers can trust. She covers everything from nutrition and mental wellness to chronic disease management, always grounding her work in credible science and real-world relevance. When she's not writing, she's usually reading up on the latest health studies or exploring new wellness trends to write about next.
