FDA laboratory worker injects an influenza virus into an egg,
where it will grow before being harvested.Food
and Drug Administration
- The most common kind of flu shot is grown in
- For years, clinicians were coached to ask if patients
were allergic to eggs before administering a shot.
- But a wealth of studies confirm that the egg-based flu
vaccine is safe even for those allergic to eggs.
For years, immunologists were cautious about giving the flu shot
to folks with egg allergies. Because most flu vaccines are grown
in eggs, they have trace amounts of egg protein in them.
“Are you allergic to eggs?” used to be a common question
clinicians would ask before administering the shot.
But no more.
Allergist Matthew Greenhawt of the American College of
Allergy, Asthma and Immunology (ACAAI) authored
new guidelines that came out Tuesday.
“Children with egg allergy of any severity can receive
influenza vaccine without any special precautions,” he told
Business Insider in an email. (It’s safe for adults too.)
But Greenhawt said his “advice is not new per se,”
since evidence has shown for years that the flu shot poses no
greater risk to those with egg allergies. The ACAAI
estimates that up to 2% of American kids have an egg allergy,
though most will outgrow it by age 16.
wealth of studies have shown that the vaccine is safe
even for patients with severe allergies to egg. In
2016, the CDC
said the shot was fine for people who break out in
hives, experience severe facial swelling (angioedema), or need a
dose of epinephrine when exposed to eggs. The American
Academy of Allergy Asthma and Immunology also says
“no special precautions are required for the
administration of influenza vaccine to egg-allergic patients no
matter how severe the egg allergy.”
Now there’s even more consensus among governmental
organizations in the US and Canada that all types of flu vaccine,
including the flu mist, are safe for almost everyone.
What to know about this year’s flu shot
Drugmakers have been making the majority of flu shots in
eggs for more than 70 years.
There are some non-egg-based shots, but they’re newer and
rarer. A recombinant vaccine, which mixes “wild” virus proteins
with insect cells, was approved by the Food and Drug
Administration in 2013. A cell-grown flu vaccine was approved in
Normally, the flu vaccine is 40-60% effective. This year’s
shot has been updated with new H1N1 parts, so it’s more effective
against circulating strains of that virus. But because a mutation
happened while the vaccine was being grown in eggs this year,
it’s proving less effective against one of the more
virulent strains circulating: H3N2.
experts say that could make this US flu season a little
rougher and the vaccine could be a bit less effective than
usual. But you should still get the shot to help protect against
all other circulating strains. (Doctors are not recommending the
flu mist for the 2017-2018 flu season, because it’s been less
effective in recent years.)
Flu season is expected to peak between late December and
March 2018, and is already circulating widely in the southeastern
The weekly influenza
surveillance report for December 4-9, 2017 shows “influenza like
illness” spreading across the southeastern US.Centers for Disease
Control and Prevention
In rare cases, people can have an allergic reaction to the
flu vaccine, but that type of vaccine-inducedanaphylaxis is extremely rare — it happens to about one in
every one million vaccine recipients, regardless of other