Flu Shot Questions and Answers

With some common misconceptions floating around on the internet and elsewhere, Dr. David Baum, Senior Vice President of Medical Services for Thompson Health, provides answers to some common questions about flu shots.

Can I get the flu from the flu vaccine?

No. There are two types of influenza vaccines:

• Dead virus from cultures done in eggs. These cause an immunological reaction, so when a live influenza virus is encountered, the body fights that virus, rapidly minimizing its effect on a vaccine-protected individual.
• Live vaccines in which a weaker influenza virus is nasally injected. This type of vaccine affects only the nasal passages, creating a limited response to a virus that is encountered.  This vaccine is used predominantly in younger individuals.

If that’s true, then why don’t some people feel well after getting the shot?

The vaccine may cause some local reaction at the site of injection, general malaise or even a low-grade fever for about 24 to 48 hours. This may be due to prior protection from immunizations or past exposure to the natural live virus.

It is not recommended to treat these mild reactions with acetaminophen (neither ibuprofen nor aspirin) since some studies indicate less response on the part of the immune system when individuals have used these medications to treat these symptoms.

Flu is not that serious, right?

Wrong. Yearly, seasonal influenza kills about 35,000 to 40,000 Americans. It also leads to several admissions to hospitals, especially among the elderly, who are more susceptible to developing a secondary bacterial pneumonia.

But I'm healthy -- why do I need to worry about getting the flu?
Influenza can affect a healthy individual and cause that person to be ill for several days, unable to go to work. During that time period, the individual is also highly contagious, thus potentially infecting less healthy individuals who can then develop more serious medical problems. The very young and the very old are particularly affected by this transmission.

Isn't it too late to get a flu shot anyway?

Influenza usually attacks in late fall or early winter, the exception being 2009 with the Novel H1N1 influenza which appeared in late summer and early fall. Influenza takes anywhere from three to six weeks to develop adequate immunity from vaccination. So it is not too late to be vaccinated! Note that there are three different strains of influenza in each vaccine (two type A influenza and one type B), thus rendering more protection.

I heard I should demand a mercury-free flu vaccine?
Thimerosal, a compound that contains mercury, is used as to preserve the vaccine when it is in a multi-dose vial. Based on the number of studies indicating that thimerosal is not associated with neurodevelopmental disorders such as autism, the vast majority of physicians believe that a vaccine from a multi-dose vial is entirely safe.

New York State Public Health Law does prohibit administration of vaccines containing more than trace amounts of thimerosal to children under the age of 3 and women who are pregnant. When single-dose vials are not available to individuals who have a concern about thimerosal but who do not fall into either of those categories, the nasal vaccine mentioned above is an option.

The most important thing is that you get vaccinated.