Image by Arek Socha from Pixabay 

November 12, 2024 - By Lorna Fernandes - As fall arrives, so does respiratory syncytial virus or RSV season. This year, there are more options for those most susceptible to RSV, including a new vaccine and updated RSV vaccine guidance for seniors.

Carina Marquez, MD, associate professor of Medicine in the Division of HIV, Infectious Diseases, and Global Medicine at Zuckerberg San Francisco General, Peter Chin-Hong, MD, professor in the UCSF Health Division of Infectious Diseases and Theodore Ruel, MD, chief of the Division of Pediatric Infectious Diseases and Global Health at UCSF Benioff Children’s Hospitals, explain what we need to know about the RSV virus and vaccine.

What is RSV?

RSV is a virus that can cause lung and respiratory tract infections such as bronchiolitis and pneumonia. Most RSV infections clear up by themselves in a couple of weeks, but, for some people at high risk, it can cause serious illness leading to hospitalization or death.

Who is most vulnerable to RSV?

• Premature infants, newborns and babies – especially those younger than 8 months.
• Children younger than 2 years with chronic lung disease or congenital heart disease.
• Children with neuromuscular disorders, including those who have difficulty swallowing.
• Children of Native American descent.
• Adults over 75.
• Adults 60-74 with chronic medical conditions such as diabetes, heart or lung disease.
• Anyone with a weakened immune system.

How do people contract RSV?

RSV spreads much like the common cold via droplets of saliva released into the air when sick people cough or sneeze. These droplets carry the virus, spreading it when they come in contact with our eyes, noses or mouths.

What are RSV’s symptoms?

RSV symptoms are like those of a cold: congestion, fever, cough, wheezing and a sore throat. In young babies, RSV’s only signs may be difficulty breathing, irritability and decreased activity. Older adults and babies younger than 6 months may need to be hospitalized if they have trouble breathing, become dehydrated or their symptoms worsen.

What vaccines are available to protect against RSV?

There are now three vaccines available for adults and one for those who are pregnant. This summer, the FDA approved Moderna’s mRESVIA RSV vaccine for adults. Last year, the FDA approved Abrysvo (Pfizer) and Arexvy (GSK) to protect seniors from serious illness, and approved Abrysvo for pregnant women in their third trimester during the RSV season, to help safeguard newborns from the virus for up to 6 months. All three are single-shot vaccines.

Who should get vaccinated for RSV?

This summer, the CDC altered its recommended guidance to 75 years for all seniors who have not yet been vaccinated. It still recommends that seniors 60 to 74 get vaccinated if they are immune compromised or have chronic medical conditions and have not yet been vaccinated.

Pregnant women in their last trimester should talk to their health care provider about whether the vaccination is right for them.

How often should adults get the vaccine?

The RSV vaccine isn’t needed annually like the flu vaccine, but only once.

What should I know about RSV prevention for infants?

There is no vaccine approved for babies at this time, but there are ways to prevent them from getting very sick:

• Asking people sick with a cough and runny nose to wash their hands and avoid close contact with infants.
• Vaccinating pregnant women with Abrysvo in their third trimester to stimulate their immune system to make antibodies against RSV. The antibodies pass to the fetus, protecting babies for the first 6 months of life.
• Mothers who are not vaccinated can immunize vulnerable infants with Nirsevimab (Beyfortus), an anti-RSV antibody, that can prevent serious RSV in babies. Ask your doctor if your baby should get it.

How long will the new RSV vaccine protect seniors and infants from RSV?

For adults, RSV vaccines show continued protection even two years after immunization. Based on this, the CDC recommends only one dose of the RSV vaccine for seniors right now, but this may change in the future.

In infants, we know that the vaccine given to those who are pregnant protects babies for their first 6 months of life – when they are most at risk for the virus. Beyfortus, the new monoclonal antibody injection, similarly reduces the risk of RSV in infants for about five months – or one RSV season.

Does the new RSV vaccine have any side effects?

In adults, the most frequently reported side effects have been soreness at the injection site, muscle pain, fatigue, headache and joint pain. In the combined clinical trials of the vaccine, 20 out of more than 38,000 people who received the shot reported an abnormal heart rate about two weeks after vaccination. Eight people out of a similar number of folks in the trials who did not take the vaccine said the same. In addition, six people developed rare neurological complications.

Scientists are still figuring out if these irregular heartbeats or neurological complications were linked to the vaccine, but if you have concerns talk to your doctor. What is clear is that the benefit of being protected against RSV for many people far outweighs this possible risk because we don’t have good therapies once people get seriously ill with RSV.

Can I take the RSV vaccine alongside flu or COVID-19 shots?

Yes, it is safe to get all three vaccines at the same time. However, it is up to the individual to assess if they will have a reaction to the vaccinations based on their previous history of vaccines. There is no minimum waiting time between doses.
Source: UCSF