The Flu Vaccine Top Ten List

Flu season is approaching again, and with it come the usual questions and
misinformation about flu vaccines.

1) Who should get the vaccine? – The short answer is everyone older than 6 months.
This especially includes pregnant women, since the flu is associated with excess pregnancy
complications and death; people with an immune system weakened by HIV, cancer, and
transplants; and health care workers who may give the flu to their patients.

2) Should anyone avoid the vaccine? – Someone who had Guillain-Barré syndrome
within 6 weeks of a prior flu shot should probably not get another vaccine.

3) When? – Now, ideally before the end of October. The shot takes about 2 weeks to kick
in, so you want to have it in time for the usual start of flu season about Thanksgiving. It’s never
too late. It’s also not too early: a shot now will still protect you next summer if you decide to
travel to Australia at the peak of their flu season (July).

4) What if I’m sick now with a cold (or whatever)? – Get the shot if even if you’re a little
sick, even with a fever. If you’re really sick you should wait, so you know if any problems are
related to the illness and not the flu shot.

5) Which vaccine? – There are several different forms of the vaccine, including a nasal
spray for younger people and a needleless injection gun. The standard inactivated vaccine,
which we give at the Clinic, is good for everyone. People over 65 should get the high dose
version. The needleless injector tends to leave a lot of bruises, and the nose spray is expensive.
The basic shot in the arm makes your arm a little sore but is still the standard.

6) What about egg allergies? – Most of the vaccines are prepared in chicken eggs (450
million eggs a year!) and contain very small amounts of egg proteins. Even in people with
documented egg allergies, the current recommendations are to give the same vaccines without
any special precautions. The rate of severe allergic reactions is about 1 in every 740,000

7) Does the vaccine prevent the flu? – Tough question. The answer is yes, but not
always. The vaccine reduces the chance of getting the flu by about 40%. That’s not great, but a
lot of people get the flu. In the US every year between 9 and 36 MILLION people get the flu,
140-710 thousand are hospitalized, and 12-56 thousand die. That’s about the same as the
number of traffic deaths in the US. Even a small change in those numbers adds up to a lot of

8) Why is the vaccine different every year? – The virus mutates constantly, and your
immune system doesn’t see this until you’re exposed to the new strain. The World Health
Organization monitors the strains that are active and chooses the 3 or four that they think are
most likely to be prevalent. This year 2 of the strains are the same as last year and 2 are new. It
takes about 6 months from the time the strains are chosen until the vaccine is produced
(remember the 450,000,000 chicken eggs) so sometimes the virus has mutated again even
before the vaccine can be made.

9) Can someone get the flu from the vaccine? – No, the vaccine has no active influenza.
End of story.

10) What about Covid-19? Influenza and Covid-19 are different diseases caused by
different viruses, and they are vaccinated separately. You certainly don’t want to get both, so
get the flu vaccine now and get the Covid-19 vaccine when you can (we don’t know yet when
that will be).