The New York Times’ Well blog recently answered a reader question about the risks associated with flu vaccines.
There are two types of flu vaccine: a shot and a nasal spray and each type has small, but different, risks the Times explains.
The shot form contains a killed version of the virus so it cannot give the recipient the flu. But since it is grown in eggs, it can cause an allergic reaction in people with egg allergies, according to the Times. The shot—and the flu—have been linked to Guillain-Barre syndrome, a rare nerve disorder. Dr. Shira Doron, an infectious disease physician and epidemiologist at Tufts Medical Center in Boston, says that anyone who has developed Guillain-Barre disorder within six months of a previous flu vaccine should discuss this with a health care provider before getting a flu shot.
After getting a flu shot, the vaccinated individual may have a sore arm and a low-grade fever for a few days, the Times reports.
The second form of flu vaccine is a nasal spray, FluMist. The spray does contain live virus, meaning there is a small chance that it could cause flu infection in a person with a compromised immune system. Doctors therefore do not recommend the nasal spray for anyone with a weakened immune system, including pregnant women, children younger than 2, those undergoing cancer treatment, or frail older people. Anyone who lives with an immunocompromised person could theoretically pass on the virus and such individuals would be advised to get the shot instead of the nasal spray, Dr. Doron told the Times. People with asthma or recent wheezing should also avoid FluMist, which could worsen airway issues. Children taking aspirin should avoid the spray as well, because aspirin use and flu have been linked to Reye’s syndrome, a rare but sometimes fatal swelling of the liver and brain.
Though years of research have shown no connection between thimerosal, a mercury-based preservative in vaccines, and autism, some parents remain concerned about this possibility. Dr. Doron told the Times that multi-dose vials of flu vaccine contain a small amount of thimerosal. For that reason, she said, Tufts purchases only single-dose vials, which do not have thimerosal, “just so that we never have to have that conversation.”
Dr. Doron noted that the risks of flu “are much higher than the risks of the flu vaccine.” Between 1976 and 2006, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people, according to the Centers for Disease Control and Prevention (CDC).
Flu vaccination also helps protect other people in a person’s life, including babies who are too young to be vaccinated, people whose bodies do not generate sufficient antibodies in response to the vaccine, and those with compromised immune systems who cannot be vaccinated. A flu shot is “for yourself and it’s for everybody else,” Dr. Doron said.