Why do some people think that getting a flu vaccine can cause them to get RSV?
The usual suspects…
Do Flu Vaccines Cause RSV?
Like the flu, RSV or respiratory syncytial virus, causes infections during cold and flu season.
Unlike the flu, we don’t yet have an RSV vaccine, but that hasn’t stopped anti-vax folks from trying to link them together.
Of course it is silly think that a flu shot could cause a child to develop RSV.
For one thing, you can just look at who gets RSV, especially severe RSV infections.
“The average seasonal RSV hospitalization rate in this study was 5.2 per 1000 children who were <24 months old, but the rate varied by season as much as fourfold. Nevertheless, 1-month-old infants consistently were most likely to be hospitalized, almost twice as often as the next 2 most at-risk groups: infants <1 month old and infants 2 months old. These youngest infants accounted for an important proportion of all children admitted with RSV infection in the first 2 years of life: 11% were infants <1 month old, 44% were ≤2 months old, and only 36% were >5 months old.”
Hall et al on Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age
While anyone can get RSV, even adults, it is infants who are under 6 months old that typically are at the greatest risk to have severe infections. And of course, these kids are too young to even have a flu vaccine!
The other reason?
RSV season not only starts before flu season, but often before the time when we are even giving flu vaccines!
Anyway, the whole idea that “RSV is an adverse reaction from flu vaccine” comes from the misuse of a study, Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine, that doesn’t even mention RSV.
“Being protected against influenza, TIV recipients may lack temporary non-specific immunity that protected against other respiratory viruses.”
Cowling et al on Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine
And it is very important to keep in mind that it was a small study about interference caused by non-specific immunity.
Another larger study that did include RSV, “Influenza vaccination is not associated with detection of noninfluenza respiratory viruses in seasonal studies of influenza vaccine effectiveness,” found that “influenza vaccination was not associated with detection of noninfluenza respiratory viruses.”
What to Know About Flu Vaccines Causing RSV
The bottom line is that flu vaccines do not cause RSV and do not increase your risk of getting RSV.
More on Flu Vaccine Side Effects
- Can Flu Shots Cause the Flu?
- What Are the Side Effects of the Flu Vaccine?
- I’m Not Anti-Vaccine, I Just Don’t Believe in Flu Shots
- Treating Hard to Control RSV
- Does Your Child Need an RSV Test?
- Do My Kids Need the RSV Vaccine?
- Study – Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age
- Study – Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine
- Flu vaccine study does not show it causes 5.5X more respiratory infections
- Study – Influenza vaccination is not associated with detection of noninfluenza respiratory viruses in seasonal studies of influenza vaccine effectiveness
- One Flu Into the Cuckoo’s Nest*