Seasonal influenza activity is beginning to increase earlier than many recent U.S. seasons, with the latest federal surveillance showing 2.5% of clinical laboratory tests positive for influenza and influenza A accounting for nearly 95% of detected viruses. The Centers for Disease Control and Prevention’s FluView report for the week ending October 1 recorded 1,021 positive specimens among 40,709 tested in clinical laboratories, with the highest activity concentrated in parts of the Southeast and south-central United States.

The national numbers remain far below those typically seen at the peak of a severe influenza season, but their timing is drawing attention. Influenza circulation was heavily disrupted during the first years of the COVID-19 pandemic, and public-health officials have warned that lower recent exposure, uneven vaccination and simultaneous circulation of SARS-CoV-2 and other respiratory viruses could create a demanding winter for hospitals and outpatient practices.

Influenza A is driving the early signal

Among positive clinical specimens reported to CDC, 94.9% were influenza A and 5.1% influenza B. Public-health laboratories that performed subtype testing found both A(H3N2) and A(H1N1)pdm09 viruses, with H3N2 representing the majority of the small number of subtyped influenza A samples in the latest week.

H3N2-predominant seasons can place substantial pressure on older adults, although the distribution of circulating strains can change as the season develops. CDC’s surveillance system combines clinical laboratories, public-health laboratories, outpatient illness reporting, hospitalization networks and mortality data, making week-to-week trends more important than any single count.

A separate CDC respiratory-virus surveillance report published October 7 underscores why officials are watching pediatric respiratory disease closely. The agency documented changes in circulation of influenza and other respiratory viruses among children during the pandemic period, showing how sharply normal seasonal patterns can shift when population behavior and immunity change.

Vaccination recommendations are already in place

CDC’s 2022–2023 influenza vaccination recommendations call for annual vaccination of everyone 6 months and older who does not have a contraindication. For adults 65 and older, the guidance expresses a preference for higher-dose, adjuvanted or recombinant vaccines when available, based on evidence that they may provide better protection in an age group at high risk of severe disease.

The American Academy of Pediatrics has issued parallel recommendations for children, urging vaccination for all children and adolescents beginning at 6 months of age. The group also recommends prompt antiviral treatment for children hospitalized with influenza, those with severe or progressive illness and those with underlying conditions that increase the risk of complications.

The pediatric guidance notes a practical challenge: childhood influenza vaccination coverage lagged during the 2021–2022 season. That leaves vaccination campaigns with less margin for delay if influenza accelerates before the traditional late-fall and winter peak.

This season’s vaccine was selected months ago

The strains included in the U.S. vaccine are chosen through an international and domestic review process that begins well before the season. The World Health Organization’s Northern Hemisphere recommendation in February identified the virus components for the 2022–2023 vaccine, incorporating global virologic and antigenic surveillance.

In March, the Food and Drug Administration convened its Vaccines and Related Biological Products Advisory Committee to review U.S. strain selection. The FDA meeting record includes surveillance presentations, candidate-vaccine-strain materials and the committee’s recommendation for the formulation used by manufacturers for this season.

That process cannot predict the exact intensity or timing of the coming season. Its purpose is to match vaccine antigens as closely as possible to viruses expected to circulate while allowing manufacturers enough time to produce and distribute hundreds of millions of doses.

An early increase, not yet a national surge

The current data should be interpreted with precision. A 2.5% positivity rate is evidence of increasing circulation, not evidence that the United States has already reached a winter influenza peak. The most important question is whether successive surveillance reports show sustained increases in outpatient illness, test positivity and hospitalizations across more regions.

The Academy’s accompanying technical report emphasizes that influenza burden can vary widely from year to year and that vaccination and timely antiviral treatment remain the principal tools for reducing severe outcomes. Those recommendations take on greater urgency when activity begins earlier because fewer people may have completed vaccination before community transmission rises.

For hospitals, physicians and public-health agencies, the early October signal is therefore less about forecasting a specific peak than about preparation. Influenza A is already dominant among detected viruses, activity is increasing in several regions and the country is entering its first autumn in several years without many of the broad community mitigation measures that suppressed respiratory-virus transmission. The next several weeks of surveillance will show whether the early rise remains regional or develops into a broader national wave.