Winter Virus Season 2026: RSV Protection Expands as Health Officials Expect Peaks Near Last Year's Level

Health officials across the Northern Hemisphere are preparing for the 2026–27 winter respiratory virus season, with the United States Centers for Disease Control and Prevention (CDC) expecting hospital peaks from COVID-19, influenza and RSV to land near last season's level even as early flu activity climbs — and with RSV prevention expanding worldwide through new vaccine options for pregnant women, infants and older adults.

What Happened

In its October 16, 2026 outlook, the CDC reported that COVID-19 activity remained elevated in some regions of the United States but was declining nationally, that RSV activity was very low, and that rhinoviruses and enteroviruses — common causes of colds — were elevated. The agency's central message was reassuring in tone but practical in substance: this winter will likely look familiar, and the steps that helped last season still apply.

The outlook arrived in the same month that RSV prevention took several visible steps forward around the world. In September 2026, the World Health Organization (WHO) prequalified a multi-dose presentation of the RSVpreF vaccine Abrysvo, adding to the single-dose presentation it had prequalified in March 2025. Prequalification is a key gateway: it signals that a vaccine meets WHO standards for quality, safety and efficacy, and it opens the door for countries and procurement agencies to introduce it in national immunisation programmes.

Illustration: A nurse offers a flu vaccine to an older adult at a vaccination clinic as the winter vaccination season gets under way.

National campaigns are putting the new tools to work. Mexico opened its Campaña Nacional de Vacunación on October 12, 2026, running through April 2, 2027, with a goal of delivering 50 million doses against influenza, COVID-19 and pneumococcus. This season the programme adds an RSV vaccine for pregnant people at 32–36 weeks of gestation, designed to transfer early protection to infants in their first months of life. In Canada, the province of Nova Scotia announced that, beginning October 25, infants born on or after May 1, 2026 who are under eight months of age can receive RSV immunisation, with high-risk children under two also eligible, in a programme running until May 8, 2027.

Background

Respiratory syncytial virus, better known as RSV, is a common virus that usually causes mild, cold-like symptoms but can turn serious for the very young and the very old. Infants can struggle to breathe and feed, while older adults with heart, lung or immune conditions face a higher risk of hospitalisation. For decades, prevention relied mainly on hygiene and supportive care, because no vaccine existed. That changed only in recent years, as the first RSV vaccines and long-acting antibody products reached the market.

The CDC's current RSV guidance reflects that shift. Adults aged 75 and older, and adults aged 50–74 who are at increased risk, are recommended to receive a single dose of an age-appropriate RSV vaccine. Infants under eight months can be protected through maternal vaccination during pregnancy or through a long-acting antibody shot. For influenza, the CDC recommends annual vaccination for everyone aged six months and older, ideally in September or October — and notes that flu vaccines prevented an estimated 180,000 hospitalisations in the 2024–2025 season alone.

The vaccine lineup itself keeps evolving. In August 2026, the U.S. Food and Drug Administration approved Moderna's mRNA flu vaccine, mFlusiva, for adults aged 50 and older — the first mRNA-based influenza vaccine to reach that milestone.

Illustration: A pregnant woman receives an RSV vaccine, a step that can pass early protection to her baby in its first months of life.

Why It Matters

The winter respiratory season is one of the most predictable pressures on health systems every year, and predictability is useful: hospitals can staff wards, families can plan, and vaccination campaigns can be timed to when they do the most good. The CDC's outlook — peaks near last season's level — is not a promise of a mild winter, but it does suggest the season is unlikely to be dramatically worse than the one health systems just handled.

The RSV expansion matters most for the two groups the virus hits hardest. For babies, protection in the first months of life can mean the difference between a mild illness at home and a hospital stay. For older adults, a single RSV dose adds to a seasonal toolkit that already includes flu and COVID-19 vaccines.

What Happens Next

Health officials say the best window for vaccination is September and October, and they urge people to get vaccinated by the end of October — while stressing that a later dose still provides important protection. The CDC says it will update its outlook if any virus shifts course and posts new respiratory data every Friday, so the picture will sharpen as the season progresses.

Families with an infant, an older parent or someone with a chronic condition at home may want a plan now: where to get tested, how to reach a doctor after hours, and what warning signs should trigger urgent care. The CDC lists trouble breathing, persistent chest pain or pressure, and confusion as reasons to seek care promptly.

Illustration: Hospital staff review preparations for the winter respiratory virus season, which officials expect to resemble last year's.

For most people, the season's advice remains refreshingly ordinary: get the recommended vaccines, rest and stay hydrated when ill, and seek care early for severe symptoms. The new RSV options simply extend that ordinary protection to the youngest and oldest among us.

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FAQ

When is the best time to get a flu vaccine?

Health authorities recommend September or October, ideally before flu activity peaks. Vaccination later in the season still provides important protection, so a missed October appointment is not a reason to skip the shot entirely.

Who should get an RSV vaccine?

According to CDC guidance, adults aged 75 and older and adults aged 50–74 at increased risk should receive a single dose. Infants under eight months can be protected through maternal vaccination during pregnancy or a long-acting antibody shot.

What is new about RSV prevention in 2026?

WHO prequalified a multi-dose presentation of the RSVpreF vaccine Abrysvo in September 2026, and countries including Mexico have added RSV vaccination for pregnant people to their national winter campaigns, while regions such as Nova Scotia have opened RSV immunisation for eligible infants.

How bad is this winter's respiratory season expected to be?

The CDC's October 2026 outlook expects hospital peaks from COVID-19, flu and RSV to be near last season's level, with early flu activity climbing and RSV activity very low at the time of the update. The agency says it will revise the outlook if any virus shifts course.

When should I seek urgent care for a respiratory illness?

Seek care promptly for trouble breathing, persistent chest pain or pressure, confusion, difficulty staying awake, or a fever or cough that improves and then returns or worsens. For infants, fast or laboured breathing, bluish lips, or not drinking enough fluids are warning signs.

Sources

• U.S. Centers for Disease Control and Prevention, respiratory virus activity update and winter outlook, October 16, 2026 (as reported by Health Journal Online)
• World Health Organization, prequalification of multi-dose RSVpreF vaccine Abrysvo, September 2026 (as reported by Health Journalists Network Uganda)
• Secretaría de Salud, Mexico, Campaña Nacional de Vacunación 2026–2027, opened October 12, 2026 (as reported by Particle News)
• Government of Nova Scotia, vaccines available as respiratory illness season approaches, October 8, 2026
• Minnesota Academy of Family Physicians, respiratory vaccine guidance for family physicians, 2026–27 season