How Maternal RSV Vaccination and Infant Immunization Are Protecting Babies in the 2025–2026 Season

Bottom line for families: In the 2025–2026 RSV season, most babies in the United States can be protected in one of two ways—either through a vaccine given during pregnancy or a preventive antibody shot given directly to the infant. Together, these strategies are reducing the number of babies hospitalized with severe RSV.

Respiratory syncytial virus (RSV) is a common virus that infects nearly all children by age 2. For most, it causes cold-like symptoms. But in infants—especially those under 6 months—it can lead to bronchiolitis (inflammation of the small airways), pneumonia, and hospitalization.

This season, pediatricians and obstetricians are using a coordinated, two-part prevention plan recommended by the Centers for Disease Control and Prevention (CDC) and supported by the American Academy of Pediatrics (AAP). Here’s what families should know.

The Two Main Options: Vaccine During Pregnancy or Antibody for Baby

1. Maternal RSV vaccination during pregnancy

The RSV vaccine Abrysvo, approved by the U.S. Food and Drug Administration (FDA), is recommended by CDC for pregnant people between 32 and 36 weeks of gestation, during RSV season (generally fall through early spring in most of the U.S.).

The goal is to help the pregnant person’s immune system make antibodies against RSV. Those antibodies cross the placenta and protect the baby during the first months of life—when the risk of severe RSV is highest.

According to CDC clinical guidance for the 2025–2026 season, most infants do not need nirsevimab if their mother received RSV vaccination during pregnancy at the recommended time window.

2. Nirsevimab for infants

Nirsevimab (brand name Beyfortus) is not a vaccine. It is a long-acting monoclonal antibody approved by the FDA to provide direct protection against RSV in infants and some young children.

It is recommended for:

Infants younger than 8 months entering their first RSV season if the mother did not receive RSV vaccine during pregnancy
Some high-risk children 8–19 months old entering their second RSV season (such as those with certain chronic lung or heart conditions)

Unlike traditional vaccines, nirsevimab does not train the baby’s immune system. Instead, it provides ready-made antibodies that circulate for several months, covering a single RSV season.

What Early Real-World Data Show

Initial clinical trials showed strong protection from both approaches. Now, real-world data are helping confirm how they perform outside controlled studies.

Recent reports published in the CDC’s Morbidity and Mortality Weekly Report (MMWR) during the 2024–2025 season found that:

Maternal RSV vaccination reduced the risk of RSV-related hospitalization in young infants during their first months of life.
Nirsevimab significantly reduced RSV-associated hospitalizations among infants receiving the antibody.

These analyses were observational, meaning researchers compared outcomes among vaccinated or immunized infants versus those who were not, rather than conducting randomized trials during the season. Observational studies can be influenced by factors such as healthcare access or underlying health differences. However, the findings have been consistent with earlier randomized clinical trial results reviewed by the FDA.

Public health officials report that these strategies are helping prevent surges in pediatric hospitalizations that were common in previous RSV seasons.

How Families Decide Which Option Applies

In most cases, families will not need both.

If a pregnant person receives RSV vaccination at 32–36 weeks during RSV season, the baby generally does not need nirsevimab.
If the mother was not vaccinated—or if the baby is born outside the recommended vaccination window—the infant should receive nirsevimab before or at the start of RSV season.

There are exceptions. Some high-risk infants may still qualify for nirsevimab even if maternal vaccination occurred. Pediatricians follow CDC and AAP guidance to determine eligibility.

What If a Baby Is Born Outside RSV Season?

RSV season typically runs from fall through early spring, but timing varies by region.

If a baby is born in spring or summer, protection may be planned for the upcoming RSV season in the fall. Pediatricians review birth timing, maternal vaccination history, and local RSV activity to decide when to administer nirsevimab.

Safety Monitoring and What’s Known So Far

The FDA approved maternal RSV vaccination and nirsevimab after reviewing randomized clinical trial data showing protection against severe RSV disease.

Common side effects of maternal RSV vaccination include injection-site reactions, fatigue, and headache. Nirsevimab may cause mild injection-site reactions or rash. Severe allergic reactions are rare but possible with any biologic product.

Safety monitoring continues through federal systems such as the Vaccine Adverse Event Reporting System (VAERS) and other surveillance networks. As with all new immunization strategies, ongoing monitoring helps identify rare events that might not appear in clinical trials.

Insurance Coverage and Access in 2025–2026

Under federal vaccine policy:

Most private insurance plans must cover CDC-recommended vaccines without cost-sharing.
Maternal RSV vaccination is generally covered under preventive services benefits.
Nirsevimab is included under the Vaccines for Children (VFC) program for eligible infants.
Medicaid programs cover ACIP-recommended immunizations for children, though rollout logistics can vary by state.

Analyses from KFF note that early implementation challenges in previous seasons have improved as supply chains stabilized and coverage guidance became clearer. Families who encounter billing issues should contact their insurer or state Medicaid office for clarification.

Who Is at Highest Risk for Severe RSV?

Even with prevention tools available, certain babies remain at higher risk:

Premature infants
Infants under 6 months
Babies with chronic lung disease or congenital heart disease
Infants with weakened immune systems

Parents should seek medical care urgently if a baby has:

Fast or labored breathing
Chest retractions (skin pulling in between ribs)
Poor feeding
Blue lips or fingernails
Unusual lethargy

What This Means for Families in 2025–2026

For the first time, RSV prevention in infants is no longer limited to high-risk babies. Most newborns can now be protected through one of two coordinated approaches.

That does not eliminate RSV entirely. Babies may still get infected, and no preventive measure offers perfect protection. But reducing the risk of severe disease and hospitalization in the most vulnerable months of life is a significant public health step.

If you are pregnant or expecting a baby this year, talk with your obstetrician or pediatrician about:

Your due date relative to RSV season
Whether maternal vaccination is recommended
Whether your newborn will need nirsevimab
Insurance coverage and scheduling

For many families this season, RSV protection is built into routine prenatal and newborn care. That coordination between obstetricians, pediatricians, insurers, and public health agencies is what is helping reduce hospitalizations across the country.

As always, recommendations may evolve as new data emerge. Following guidance from CDC and your child’s healthcare provider remains the most reliable way to make decisions for your family.

Sources

This article is for general informational purposes only and is not medical advice. Research findings can be early, limited, or subject to change as new evidence emerges. For personal guidance, diagnosis, or treatment, consult a licensed clinician. For current outbreak or public health guidance, follow your local health department, the CDC, or another relevant public health authority.