This article is intended to provide information about the RSV vaccine in adults and factors to consider when thinking about getting the vaccine. For your specific situation, I recommend you consult with a trusted clinician to arrive at a decision tailored to your medical needs.
What is RSV?
RSV stand for Respiratory Syncitial Virus. It is an RNA virus belonging to the Pneumoviridiae family of viruses and one of the pathogens that cause the common cold between October and May in the Northern hemisphere. Most people who contract RSV experience mild cold symptoms: sore throat, runny nose, cough, and congestion. These are signs of infection in the upper respiratory tract (nose, mouth, and throat). In certain cases, the virus can migrate to the lower respiratory tract (the trachea or windpipe and lungs) and cause a more serious infection up to and including pneumonia. Some studies show that RSV can cause death in up to 8% of people 50 and older who are hospitalized with RSV infection. The CDC notes that RSV causes 6,000 to 10,000 deaths per year in people 65 years and older and an order of magnitude more hospitalizations (60,000 to 160,000 per year) in that age group. People who suffer from medical conditions like lung disease (i.e. asthma and COPD), heart disease (i.e. congestive heart failure, coronary artery disease), neurological disorders, kidney disease, diabetes, chronic liver disease, blood disorder, and a suppressed immune system have a higher risk of complications with RSV infection.
How is RSV Transmitted?
RSV is transmitted from transferring secretions containing the virus to the nose, mouth, or eyes. The virus can live on surfaces for several hours, which is why it is important to clean shared surfaces and clean your hands before touching your mouth, eyes, and nose. The incubation period for RSV is generally four to six days.
The Vaccines
There are two new vaccines approved for prevention of RSV in adults 60 and older: Abrysvo made by Pfizer and Arexvy made by GSK. Both vaccines are administered as a single dose. Both vaccines are recombinant vaccines. A recombinant vaccine is made by engineering an organism, usually bacteria, to produce a protein found in the vaccine’s target pathogen (RSV in this case). This protein is purified and packaged in a vaccine. When injected, it triggers the immune system to produce antibodies against the target pathogen. The main difference between the vaccines is that Arexvy (the GSK vaccine) contains a substance called and adjuvant (AS01E in this case) that primes the immune system to generate antibodies.
Efficacy of the Vaccines
Abrysvo (the Pfizer vaccine) was tested in around 37,000 study participants 60 and older in 7 different countries. A single dose of the vaccine was studied across two RSV seasons. During the first RSV season, it was found to prevent lower respiratory tract disease in 88.9% of study participants who received the vaccine. During the second season, this protection dropped to 78.6%. The combined efficacy of the vaccine across the two seasons was 84.4%.
Arexvy (the GSK vaccine) was tested in around 25,000 study participants in 17 different countries. A single dose of the vaccine was studied across two RSV seasons. During the first RSV season, it was found to prevent lower respiratory tract disease in 82.6% of study participants who received the vaccine. During the second season, this protection dropped to 56.1%. The combined efficacy of the vaccine across the two seasons was 74.5%
Side Effects of the Vaccines
With Abrysvo (the Pfizer vaccine), the most common side effects among people who received the vaccine were fatigue (16%), headache (13%), and pain at the injection site (11%). Reactions severe enough to impair normal activities occurred in 1% of people who received the vaccine. Three people who received the vaccine reported serious inflammatory neurological conditions including Guillain-Barré syndrome. People who received the vaccine also reported more instances of atrial fibrillation (a form of abnormal heartbeat).
With Arexvy (the GSK vaccine), the most common side effects among people who received the vaccine were pain at injection site (61%), fatigue (34%), muscle pain (29%), and headache (27%). Reactions severe enough to impair normal activities occurred in 4% of vaccine recipients. Three people who received the vaccine reported serious inflammatory neurological conditions including Guillain-Barré syndrome and encephalomyelitis (inflammation in brain tissue). People who received the vaccine also reported more instances of atrial fibrillation (a form of abnormal heartbeat).