|  | Conditions Treatments | Infectious Diseases

Reactions to the Flu Vaccine

In the United States, Novartis produces the leading injectable form of influenza vaccine, Fluvirin, while MedImmune produces the only approved intranasal form, FluMist. Most people vaccinated with either form have their resistance to flu raised and experience few or very mild side effects. Neither flu shots or nasal sprays come without risks, however, so patients need to inform themselves about what to expect when getting vaccinated.

  1. Immunity

    • No flu vaccine provides complete protection against infection because the types of influenza viruses that circulate from year to year change. The vaccine formulations also change each year to keep pace with mutations, and when a good match occurs between circulating strains and the strains in vaccine, protection can reach as high as 90 percent. Even in years of poor matches, the immunity rate among people who receive flu vaccines is around 70 percent.

    Flu Shot Side Effects

    • People may feel some soreness around the injection site after getting a flu shot. The skin around the needle stick may also turn red for a brief time, and patients may develop a low-grade fever.

    Flu Shot Contraindications

    • Children younger than 6 months of age should not receive flu shots. Also, anyone with an active illness that produces a fever should wait until she has fully recovered from that illness before receiving a flu shot. Having developed Guillain-Barré within a month and a half of having received an earlier flu shot disqualifies someone from receiving another one in the future.

    Nasal Vaccination Side Effects

    • The most common side effects among people who have received the double sprays of FluMist vaccine have been a runny nose, a slight fever, nasal congestion and sore throat. Some patients have also experienced headaches, coughs, muscle aches and wheezing.

    Nasal Vaccination Contraindications

    • Egg, gentamicin and gelatin allergies bar people from receiving FluMist. Also, children who are taking aspirin or who are younger than 2 years of age must receive flu shots rather than the intranasal vaccine. Health care providers must decide whether the benefits of administering FluMist to people with asthma, people who have had Guillain-Barré, people with weakened immune systems or people heart disease or diabetes outweighs the risks.

Infectious Diseases - Related Articles