RSV(P)

Respiratory syncytial virus (RSV) is a virus you may never have heard about, but you’ve probably had. It affects the upper airways with cold like symptoms, but it can cause a severe pneumonia, particularly in infants, older adults, and those with lung disease, or who are immunocompromised. By two years old almost all children have been infected. It causes roughly 2/3 of the number of hospitalizations and deaths as that cause by influenza (the flu). It tends to peak around the same time as influenza and COVID-19, constituting a triple threat.

There is a monoclonal antibody for infants and young children, but this year for the first time adults 60 and older can get a vaccine for RSV.

There are currently two vaccines approved, Abrysvo from Pfizer,and Arexvy from Glaxo Smith Kline’s (GSK). Abrysvo is also approved for women who are 32 to 36 weeks pregnant during September through January (to cover when RSV is typically active). Full disclosure – I was a primary research investigator for one of the Pfizer’s studies, but I make no money from sales of the product.

In one study with Arexvy and influenza vaccines there were two cases of acute disseminated encephalomyelitis (ADEM), and one case of Guillain-Barré syndrome, serious neurologic side effect seen with some other vaccines, and sometimes for no apparent reason. It’s not clear if it was due to the RSV vaccine component, the influenza component, the combination, or unrelated. There were 3 reported cases of Guillain-Barré in the Abrysvo studies.

Although there were few reported cases of Guillain-Barré in the RSV studies, given the severity of the side effect one needs to consider risk versus benefit. For those at high risk, I think the benefit outweighs the risk. It’s harder to know what to do for those who are approved to get the vaccine, but are otherwise at low risk, such as those in their 60’s who are generally healthy. Currently for those patients I’m not encouraging them to get vaccinated, and if they ask, I say they may want to consider skipping it this season. By next season we should have a much better idea of the true risk. If you’re 60-years-old or older, you should discuss with your physician/provider.

It’s not yet known how long the vaccine provides adequate protection, but probably for 2 years or longer. In fact when the companies realized the vaccines would last more than one year, they raised their prices as their original profit calculations assumed people would need yearly vaccinations.