• Ronnie Shalev, MD

Flu Shot and Why It’s So Important

The flu vaccine is the most effective way to prevent a flu infection.

There are several types of flu vaccines:

  • Trivalent- has three strains of the influenza virus

  • Quadrivalent-has four strains of the influenza virus

  • Egg-free version- geared for patients with egg allergies

After a flu vaccination, it takes 2 weeks to develop antibodies to the influenza virus. Plan on getting vaccinated by the end of October, but it's never too late!

The influenza virus changes rapidly, so a new version of the flu vaccine is developed twice a year. The efficacy of the flu shot varies yearly and varies by individual. The flu vaccine is 50-60% effective and depends upon the influenza strains circulating and the influenza strains that are vaccinated against.

I oftentimes hear from patients that they don’t get the flu shot because “whenever I get the flu shot I end up getting the flu”. Well, it is possible to get the flu after the flu vaccine, especially if you haven’t developed antibodies to the flu yet. However, the symptoms those patients are likely talking about are the mild side effects from the flu vaccine itself, which include soreness, headaches, fever, nausea, and muscle aches. It’s also possible that they got infected with an influenza strain that was not part of the flu vaccine. However, if a patient gets vaccinated and ends up getting the flu, then typically their symptoms are milder than usual, and they will have less complications related to the flu.

In conclusion, get your flu shot. The most it will do is prevent you from getting the flu, and the least it will do is prevent you from developing a deadly complication related to the flu.