While RSV typically causes mild, cold-like symptoms, it can lead to serious and even fatal illness, especially in infants and
older adults.
RSV vaccination can help prevent dire outcomes. Read on to learn more about the vaccine, including who should get it and side effects.
For decades, scientists had been searching for a vaccine that could fend off RSV and reduce the chance of extreme illness. A breakthrough finally came in 2013 when researchers identified a protein in RSV dubbed pre-fusion (F) or preF for short, which allows the virus to attach to human cells.
With this knowledge, scientists were able to develop a vaccine that produces antibodies against preF, blocking the virus from entering cells.
Currently, there are three RSV vaccine options. All are formulated to protect against two subtypes of the virus, A and B.
- Arexvy In May 2023, Arexvy, from GSK, became the first vaccine approved by the U.S. Food and Drug Administration (FDA) to fight RSV, using an inactivated preF protein combined with an adjuvant (an ingredient that helps create a stronger immune response).
- Abrysvo Abrysvo, from Pfizer, also received FDA approval in May 2023. Abrysvo does not use an adjuvant, but unlike Arexvy it contains the preF protein from both RSV A and B.
- mRESVIA While Arexvy and Abrysvo utilize a traditional vaccination method similar to the kind used for the flu shot, mRESVIA, from Moderna, relies on mRNA, a technology like the kind used for the company’s COVID-19 shot. Vaccines made with mRNA teach a person’s own cells how to make a protein to trigger an immune response against a particular virus. The FDA approved the vaccine in May 2024.
The Centers for Disease Control and Prevention (CDC) recommends the RSV vaccine for the following groups.
Adults 75 Years Old and Up Because immunity to all viruses wanes in old age, the elderly are more likely to be hospitalized or die from complications of RSV.
Adults 50 to 74 With Underlying Medical Conditions or Other Special Concerns Issues that can raise the risk of severe illness include:
- Chronic lung or respiratory disease (such as chronic obstructive pulmonary disease, emphysema, asthma, or cystic fibrosis)
- Chronic cardiovascular disease (such as heart failure, coronary artery disease, or congenital heart disease)
- End-stage renal (kidney) disease or dependence on hemodialysis or other renal replacement therapy
- Diabetes complicated by chronic kidney disease, neuropathy, retinopathy, or other end-organ damage, or requiring treatment with insulin or sodium-glucose cotransporter-2 (SGLT2) inhibitor
- Neurological or neuromuscular conditions causing impaired airway clearance or respiratory muscle weakness such as post-stroke dysphagia (difficulty swallowing), amyotrophic lateral sclerosis (ASL; Lou Gehrig's disease), or muscular dystrophy
- Chronic liver disease
- Chronic hematologic (blood) conditions (such as sickle cell disease)
- Severe obesity
- Moderate or severe immune compromise
- Residence in a nursing home or other long-term facility
The CDC advises eligible older adults to receive whichever brand of RSV vaccine is available, and doesn’t recommend one type over another.
Pregnant People (to Protect Their Newborns) The FDA has approved only one maternal RSV vaccine, Abrysvo. The pregnant person’s immune system creates antibodies that get shared with the fetus,
protecting a baby during the first six months of life when the risk of an infection becoming severe is highest.
Note that other options for babies and some young children are the preventive treatments called
Beyfortus (nirsevimab) and Enflonsia (clesrovimab). These medications, a type called a monoclonal antibody, provide immediate protection against RSV and last at least five months.
For eligible older adults, the CDC recommends vaccination in late summer or early fall, before respiratory virus season kicks in.
Right now, public health officials regard RSV as a one-time lifetime shot and not an annual vaccine, although that recommendation may change as researchers learn more about how long protection lasts.
For pregnant people, the CDC urges vaccination between gestational weeks 32 and 36 when this period occurs between September and January, so babies born during RSV season will have protection.
A person should not receive the vaccine if they’ve ever had a severe allergic reaction (such as
anaphylaxis) to any component.
The effectiveness of the RSV vaccine depends on the age of the recipient and the type of vaccine.
The CDC says that studies of the real-world effectiveness of Arexvy during the 2023–2024 respiratory virus season showed the vaccine to be about 77 percent effective in preventing RSV-associated emergency room visits and 83 percent effective in preventing RSV-associated hospitalizations in adults 60 and older.
Abrysvo was found to be about 79 percent effective in preventing RSV-associated emergency room visits and 73 percent effective in preventing RSV-related hospitalizations in adults 60 and older.
In a study of pregnant individuals who received Abrysvo, newborns had nearly an 82 percent reduced risk of severe lower respiratory tract infection within 90 days after birth if their mother had been vaccinated. The risk was about 69 percent lower within 180 days after birth.
Because mRESVIA is so new, research data is more limited. A clinical trial of participants ages 60 and older, however, found that the efficacy of a single dose of mResvia against symptomatic RSV was about 80 percent during the first four months following vaccination and about 56 percent during the first 12 months after vaccination.
The FDA has deemed RSV vaccination to be both safe and effective after an evaluation of data from clinical trials.
But the CDC notes that a small number of trial participants developed serious neurological conditions, including Guillain-Barré syndrome (GBS), after receiving Arexvy or Abrysvo. GBS is a rare condition in which the immune system attacks the nerves, causing symptoms such as weakness.
The federal Vaccine Adverse Event Reporting System recorded about 10.6 million adults ages 60 years and older receiving a recommended RSV vaccine between August 4, 2023 and March 30, 2024. The data included 11 reports of GBS in those who received Arexvy and 17 cases of GBS among those who received Abrysvo.
In rare instances, a person may experience an extreme allergic reaction (anaphylaxis) to vaccination, causing hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, or weakness.
In a survey of those reporting adverse reactions to the RSV vaccine between May 3, 2023 and April 14, 2024, more than 92 percent of 2,193 who had received Arexvy and about 89 percent of 919 who received Abrysvo said these events were non-serious. A total of seven noted having an allergic reaction with two describing the reaction as anaphylaxis.
While the risk is low, some people who received the RSV vaccine during pregnancy reported preterm birth and high blood pressure, including a dangerous form called preeclampsia. In clinical trials, 1.8 percent of vaccinated pregnant people developed preeclampsia compared to 1.4 percent of pregnant people who received a placebo during 24 through 36 weeks’ gestation.
A total of 4.2 percent of infants were born preterm in the vaccine group versus 3.7 percent in the placebo group. It is unclear whether these differences are related to the RSV vaccine or if they occurred for unrelated reasons.
Side effects from the RSV vaccine are usually temporary and mild. They may include:
- Pain, redness, and swelling at the injection site
- Fatigue
- Fever
- Headache
- Nausea
- Diarrhea
- Muscle or joint pain
The vaccine does not contain a whole virus or a live virus, so it cannot cause illness or make you contagious.
The cost of the RSV vaccine depends on your health insurance plan. Medicare Part D (prescription drug coverage) covers the RSV shot. In 2024, the out-of-pocket cost for an RSV vaccine ranged from $175 to $395, according to the CDC.
RSV vaccination is available at most doctors’ offices and pharmacies. Vaccinations may also be available through your
local health department.
The Takeaway
- RSV vaccines can prevent severe respiratory illness in infants (through a vaccination of the mother), people ages 75 and older, and those ages 50 to 74 with certain underlying conditions.
- There are three RSV vaccine brands. The CDC does not recommend one over the other for older people, although Abrysvo is the only approved maternal vaccine.
- The FDA has deemed all these vaccines to be safe and effective based on data from clinical trials.
