As vaccines against respiratory syncytial virus, or RSV, become available for a second year this fall, health experts are not recommending the shot for as many people this time around.
The virus is just one pillar of the ongoing “tripledemic,” compounding with annual flu cases and seasonal spikes of COVID-19 cases after a rise in cases over the summer.
About one quarter of American adults over the age of 60 have been vaccinated against RSV, according to an Aug. 6 report from the Centers for Disease Control and Prevention.
Another vaccine against RSV has been approved by the FDA, and studies of all three shots available to older Americans have revealed some side effects that have health experts concerned.
Here is what you need to know. What shots are FDA approved?
Three different vaccines for older adults are now approved by the Food and Drug Administration, including one approved this past May.
GSK’s vaccine Arexvy and Pfizer’s vaccine Abrysvo were available last season, according to the CDC. On May 31, a third shot developed by Moderna, mResvia, was also approved.
Studies presented to the CDC’s Advisory Committee on Immunization Practices Work Group for RSV found a 78.7% efficacy of a single dose “preventing symptomatic, laboratory-confirmed (RSV) with two or more lower respiratory symptoms,” according to the report, and an 80.9% efficacy in preventing RSV with three or more lower respiratory symptoms.
The vaccines from GSK and Pfizer were found to have efficacy ranges from 75% to 82% during the first RSV season last fall, according to the report, in adults older than 60. This included adults with immunocompromising conditions.
What are potential side effects?
Studies presented to the CDC ACIP Work Group for RSV found both vaccines from fall 2023 may result in a slightly elevated risk of Guillain-Barré syndrome, a rare but serious condition.
Guillain-Barré syndrome is a condition where the body’s own immune system starts to attack nerves, causing weakness and numbness, or in extreme cases paralysis and death, according to the Mayo Clinic. The exact cause of the syndrome is still unknown, but Guillain-Barré patients typically have an infection about 6 weeks before symptom onset, including respiratory and gastrointestinal infections, or COVID-19 and Zika. Evidence gathered so far cannot conclusively prove a link between the vaccines and Guillain-Barré syndrome, but the CDC said a connection could not be ruled out.
In trials of the new vaccine, Moderna’s mResvia, there were not any cases of Guillain-Barré syndrome, but there was an elevated risk of “reactogenicity events,” or what health officials would consider “normal” side effects of a vaccine, like soreness, fatigue, redness at the shot site, or fever and headache.
There was also a slightly elevated risk of neurological and heart inflammation, according to the report.
Do I need an RSV vaccine?
With the potential side effects in mind, the CDC said in some cases the risk of a severe negative side effect outweighs the benefit of receiving the RSV vaccine, and it has updated its recommendations for 2024.
A single dose of any of the FDA-approved shots is still recommended for adults over the age of 75, the CDC said. This includes those who received a shot last year.
However, adults aged 60 to 74 should only receive an RSV vaccine this fall if they are at an elevated risk of RSV. Factors that can raise your risk of RSV include if you are immunocompromised, have a chronic medical condition or live in a nursing home, the CDC said.
If you are between 60 and 74 and received a shot last year, you should not get another RSV vaccine this year.
The three shots approved for older adults is not the same as the vaccine approved for pregnant people.
The Pfizer vaccine Abrysvo is the only RSV vaccine approved by the FDA for those who are pregnant, according to the CDC. The shot should be given during weeks 32 through 36 of pregnancy. In the United States, the shot should be given between the months of September through January.
To prevent RSV in infants, the shot can either be given during pregnancy, or an RSV monoclonal antibody can be given to the infant after birth, though a child does not need both.
What are symptoms of RSV? Respiratory syncytial virus is an upper respiratory virus that causes symptoms like a runny nose, decreased appetite, coughing, sneezing, fever or wheezing when breathing, according to the CDC. The virus spreads through water droplets, according to the CDC, when a sick person coughs or sneezes on someone else, but the virus can survive for short periods of time on commonly touched surfaces like doorknobs or countertops.
The virus has peaks during the fall and winter when other viruses like the flu and COVID-19 are also spreading, so it can sometimes be difficult to differentiate between the three illnesses.
While most people develop cold-like symptoms and recover with over-the-counter medications, RSV can be severe or deadly among older adults and infants, emphasizing the importance of vaccination among those populations.
Can I get the vaccine with a COVID booster, flu shot? You are able to get the flu shot, COVID-19 booster and RSV vaccine at the same time, and no waiting period is required between shots, the CDC says.
All shots have the possibility of side effects as the vaccine begins to work in your body, and these may be compounded when all shots are given at the same time, but it will not impact their efficacy.
As always Stay Safe, Stay Healthy and Be Careful out there.
James A Vito, D.M.D.