CDC’s Early Flu Season Warning (2025): What It Means for American Households

In September 2025, the U.S. Centers for Disease Control and Prevention (CDC) issued an early warning about flu activity across the United States, urging households and communities to be vigilant as the 2025–2026 flu season approaches. This report examines the CDC’s observations from the most recent 48 hours, along with current flu activity, the trajectory compared to previous seasons, vaccination efforts, recommendations from public health officials, and practical steps individuals and families can take now. The information is presented to be accessible and reassuring, using plain English to ensure that all U.S. households can make informed, calm decisions regarding flu prevention and preparedness.

CDC’s Early Flu Season Warning: Context and Timing

Between September 6 and September 13, 2025, the CDC’s influenza surveillance systems continued to monitor flu activity throughout the country. The agency’s latest warning does not mean widespread severe illness is occurring everywhere, but rather that flu activity has begun to increase ahead of the usual fall and winter surges. At the national level, laboratory-confirmed flu cases remain relatively low, with only 0.4% of respiratory specimens testing positive for influenza in clinical laboratories during the week ending September 13, 2025 (CDC Week 37). However, the CDC’s message is proactive: flu cases often begin to rise in some communities before the rest of the country feels the impact, and early action can help prevent widespread severe illness, especially among high-risk groups.

This early warning is rooted in a complex mix of evidence—from reports of localized outbreaks and school absences to laboratory reports and the monitoring of emergency room visits. By providing this advance notice, the CDC is working to ensure that American families, schools, healthcare providers, and public health officials have the information and time necessary to prepare effectively.

Virologic Surveillance: Lab Positivity Trends

Clinical and Public Health Laboratory Data

The CDC gathers data from both clinical (hospital-based and community-based) and public health laboratories across the nation to assess flu activity. As of Week 37 (ending September 13, 2025):

Cumulative since September 29, 2024:

• Clinical: 4,076,717 specimens, 489,945 (12.0%) positive
• Influenza A remains dominant (≈89% of cases), with H1N1 and H3N2 types co-circulating
• Influenza B (Victoria lineage) is present but at much lower percentages

These laboratory findings confirm that while transmission is at low levels nationally, flu viruses are circulating, and the composition matches the dominant strains included in the 2025–2026 vaccines.

Explanation for Households

A low percentage of positive flu tests means that the number of people currently infected with the flu is low compared to the number being tested. However, because influenza spreads quickly, especially in schools and crowded community settings, small rises can lead to larger outbreaks over several weeks.

Geographic Spread and Regional Activity

Outpatient Illness and Emergency Department Visits

The CDC maps influenza-like illness (ILI) activity across the country using the percentage of patient visits to health providers for fever plus cough or sore throat, not necessarily confirmed flu. For the week ending September 13, 2025:

• National ILI percentage: 1.7% (slightly down from 1.8% the previous week)
• Age distribution for ILI visits:
  • Ages 0–4: 5.1%
  • Ages 5–24: 2.5%
  • Ages 25–49: 1.5%
  • Ages 50–64: 0.9%
  • Ages 65+: 0.7%
• Emergency Department visits for influenza diagnosis: 0.2%
  • Highest in children 0–4 years: 0.4%

Interpretation: The vast majority of the country is at a minimal or low level of flu activity, but some isolated areas are seeing higher levels. The highest rates of doctor visits for respiratory illness are seen in preschoolers and young children.

Regional and State-Level Summary Table

In Florida, for example, ED visit data shows no significant surge, with nearly all regions recording “no change” or “decreases” in percent of ED visits for flu compared to recent averages. Georgia reports “minimal” activity; Texas state data as of early September also shows no abnormal increase.

Timing and Severity Assessment: How This Season Compares

While laboratory and outpatient surveillance suggests low activity, the early warning is partly precautionary, given the pattern observed in the previous (2024–2025) season. That season was classified as “high severity” by the CDC, with elevated hospitalization and death rates—especially in children and older adults. Over 38,000 hospitalizations and 127.1 per 100,000 cumulative hospitalization rate were recorded, with peak activity in late January through February. Some regional outbreaks, especially in schools, led to widespread absences and temporary closures in numerous states this spring.

This year, the CDC is being vigilant, paying close attention to small increases in some regions since those could quickly escalate.

Severity Metrics Defined

• ILI (Influenza-like Illness) Rate: Percentage of outpatient visits for fever + cough/sore throat, not just lab-confirmed flu
• Lab Positivity: Percentage of positive flu specimens among those tested
• Hospitalization Rate: Number of laboratory-confirmed flu hospitalizations per 100,000 population
• Pediatric Mortality: Number of flu-associated deaths among children under 18
• Geographic Spread: Based on jurisdictional (state/metro) self-reports—none, sporadic, local, regional, widespread

These layers of data help CDC and state health departments decide if the season is typical, unusually early, or severe.

Outpatient and Hospital Surveillance Metrics: Summary and Definitions

ILI Surveillance/ILINet: Collects data on patients visiting outpatient clinics, urgent care, and primary care for “influenza-like illness,” not requiring laboratory confirmation. This means that spikes in ILI could be due to flu or other respiratory viruses, such as RSV or COVID-19, especially during early fall.

National Syndromic Surveillance System (NSSP): Monitors emergency room visits for flu diagnoses, providing early warnings for severe cases.

FluSurv-NET: Tracks laboratory-confirmed, hospitalized flu cases in selected counties covering ~9% of the U.S. population.

NHSN Hospitalization Surveillance: Provides nationwide hospital admission data for confirmed flu cases, including age and location data.

Pediatric Mortality Surveillance: Counts influenza-associated deaths among people under 18.

By cross-referencing these data, the CDC and officials can gauge if trends in outpatient visits are translating into severe cases.

School Absenteeism and Closures

During the previous flu season, several states, notably Texas, Ohio, Oklahoma, Georgia, Virginia, and Tennessee, reported temporary school closures due to surges in student and staff illnesses. At the peak, over 10 states had at least some schools suspending in-person classes for one or more days; schools in Texas and Ohio reported absentee rates as high as 30–40% during the worst weeks. These closures were primarily short-term (1–3 days) and used as a tool for deep cleaning and to break transmission chains.

Recent weeks show a return to “normal” attendance levels. As of the most recent CDC and state health department updates (Week 37, September 2025), there have been no notable new school closures, and school absenteeism related to respiratory illness has decreased in all major reporting states.

The CDC and school health officials recommend prompt reporting of any clusters of illness and urge schools to follow absenteeism, hygiene, and cleaning guidelines to minimize potential outbreaks.

Hospital Preparedness and Capacity

Hospital systems in the U.S. have implemented updated pandemic and influenza surge plans, with specific attention to:

• Regular reviews of infectious disease surge policies, including surge tent planning and alternate treatment areas for pediatric and critical care patients
• Preserving personal protective equipment (PPE), antivirals, ventilators, and vaccination distribution capability
• Training staff for cross-coverage and monitoring for staff illness
• Robust infection control (screening of visitors, patient cohorting, signage, hand hygiene stations)
• Pre-registration and tracking of staff vaccination
• Coordination with local health authorities for messaging and outbreak response plans

CDC recommends all healthcare entities maintain readiness for rapid identification of severe cases, especially in high-risk populations such as those ≥65 years, young children, pregnant women, and those with underlying health conditions.

National Flu Vaccination Coverage and Supply

2025–2026 Vaccine Guidelines and ACIP Recommendations

The CDC’s Advisory Committee on Immunization Practices (ACIP) continues to recommend annual seasonal flu vaccination for everyone 6 months and older, with rare exceptions. This universal policy is supported by substantial evidence that vaccination reduces not only flu infection risk but also the likelihood of hospitalization and severe complications.

Key Updates for the 2025–2026 Season:

• Vaccine Types: All available flu vaccines are now trivalent (protecting against two influenza A types and one B Victoria lineage). Both injectable and nasal spray (FluMist) forms are available.
• Vaccine Formulations: Only single-dose, thimerosal-free formulations are recommended for children, pregnant women, and all adults, in alignment with new ACIP votes and CDC guidance.
• Vaccination Timing: Ideal period to get vaccinated is September or October. Early vaccination (July/August) is not generally preferred, except for those with restrictive scheduling, but vaccination can continue as long as flu activity is circulating and vaccine remains available.
• Older Adults (≥65): Preferential use of high-dose, adjuvanted, or recombinant vaccines due to better protection in this age group.
• Pregnancy: Vaccination is safe and recommended in any trimester; live nasal spray not recommended during pregnancy.
• Egg Allergy: Any appropriate vaccine may be used, no special precautions needed.

Most of the U.S. vaccine supply for this season is thimerosal-free and over 150 million doses are projected to be available.

Vaccination Rates

The CDC’s FluVaxView Dashboard provides weekly updates on distribution and coverage:

• Adults (as of April 2025): 46.7% (similar to last season’s 47.4%)
• Children (6 months–17 years): 49.2% (down from prior season’s 53.4%)
• Pregnant Women: 38.0% (flat from previous year)
• Adults 65+: 48.3% of Medicare fee-for-service beneficiaries
• State Variation: Jurisdictions report a wide range (from 10%–46%) depending on region and outreach efforts

Vaccination rates have not rebounded to their pre-pandemic highs, especially in children and certain minority groups.

Early Data on Hospitalizations and Pediatric Impact

Hospitalization Surveillance

• FluSurv-NET recorded 932 laboratory-confirmed flu hospitalizations in Week 37 (nationally 0.3 per 100,000), the vast majority among ages 65+ (0.8 per 100,000), with very low rates in all other age groups.
• For the 2024–2025 season, cumulative hospitalization was at historic highs (up to 127.1 per 100,000), described as the most severe since the 2009 H1N1 pandemic.

Pediatric Deaths

• Pediatric flu deaths for the season to date: 280, the highest non-pandemic total since tracking began in 2004. Of those with a known vaccination status, 90% were not fully vaccinated.
• Most severe outcomes occur in children with underlying conditions or those not yet vaccinated.

School Absenteeism

• While absences spiked in winter and early spring (in line with local school closures during outbreaks), recent reports as of September 2025 show absenteeism due to flu or ILI has normalized, with no widespread closures in any region.

Recommendations from Public Health Officials

Vaccination

• Get vaccinated: Everyone age 6 months and up should receive a flu vaccine as soon as it is available and before local flu activity rises. Vaccines are available at physician offices, pharmacies, clinics, and community pop-ups. Many sites will vaccinate without insurance at no- or low-cost; the Vaccines for Children Program covers eligible minors.

General Prevention

• Stay home when sick: Limit exposure to others if you have fever or symptoms; return only after at least 24 hours fever-free without medications.
• Practice good hand hygiene: Wash hands frequently and avoid touching your face.
• Cover coughs and sneezes: Use a tissue or elbow to limit droplet spread.
• Clean surfaces: Frequently wipe down shared surfaces, especially if someone in the home is ill.
• Masking: Consider masks in crowded or poorly ventilated indoor settings, especially during community surges or if you are at higher risk.
• Maintain distance: Stay clear of those actively sick if possible, and avoid attending large indoor gatherings if flu is rampant locally.

For Households

• Stock up on fever- and pain-reducing medications (acetaminophen, ibuprofen); consult your healthcare provider for dosing, especially for children.
• Maintain a supply of thermometers, tissues, hand sanitizer, and disinfectant wipes.
• Identify who will help with children’s or elderly family members’ care if you become sick.
• Know where the nearest urgent care or hospital is, including which facilities offer pediatric care.

For High-Risk Individuals

• Early antiviral treatment is recommended if you or your family members with high-risk conditions (including those pregnant, over 65, or with chronic illness) develop flu symptoms—seek medical advice promptly.
• Consider discussing with your provider if you need extra supplies (inhalers, nebulizer treatments for those with respiratory conditions).

School and Workplace

• Know your school or employer’s sickness, absentee, and closure policies.
• Encourage routine cleaning of commonly touched objects in classrooms and offices.
• Stay home if experiencing fever or clear flu-like symptoms.
• Schools should notify local health departments of outbreaks and follow CDC cleaning/disinfection protocols.

ACIP 2025–26 Vaccine Guidelines: Key Points

FluVaxView Vaccination Dashboard

The CDC’s FluVaxView Dashboard provides the most current, detailed information on national and regional coverage and can be accessed online. Data is updated weekly throughout flu season and helps both health officials and the public track progress towards vaccination goals.

State Health Department Alerts and Regional Responses

Many state and local health departments—including Texas, Florida, Georgia, and others—are providing weekly status updates summarizing lab test positivity, outpatient ILI visits, hospitalizations, and deaths related to influenza. These alerts support coordinated local responses in areas experiencing changes in flu activity.

Households are encouraged to follow regional health department websites or social media for localized messages, including vaccination events, school or facility closures, and other actionable alerts.

Household Preparation: Step-By-Step Summary

1. Get your flu shot at the earliest opportunity.
2. Monitor the health of household members, especially children, older adults, and those with medical conditions.
3. Prepare a basic sick-day kit with necessary medication, fluids, and hygiene supplies.
4. Review and discuss the family plan if someone becomes ill, including how to quarantine within the home if needed.
5. Stay updated with guidance from your local health department and school district.
6. Return children to school or adults to work only after being fever-free for at least 24 hours and with improving symptoms.
7. Seek medical care promptly for high fever, difficulty breathing, dehydration, or if symptoms rapidly worsen—especially in those at higher risk.

Key Takeaways for the 2025–2026 Flu Season

• Flu activity in early September 2025 is low, but a rise is anticipated in the coming weeks.
• Vaccination is the best defense: All people 6 months and older, with rare exceptions, should be vaccinated as soon as possible.
• Monitor symptoms and use common-sense hygiene and distancing, especially as local activity rises.
• Follow local alerts and CDC recommendations. Prompt action, especially in high-risk groups and during localized outbreaks, saves lives.
• Seasonal flu preparation is a community effort—participation by every household and workplace helps limit the spread and impact of annual influenza.

The CDC and state health departments will continue to provide weekly updates as the situation evolves. Households and organizations that stay informed, get vaccinated, and practice healthy habits will be best prepared to protect themselves and their communities throughout the 2025–2026 flu season.