Are Flu Vaccine Side Effects More Likely for People With Asthma?

You've probably heard that the flu shot is recommended if you have asthma. But, are people with asthma more likely to experience flu vaccine side effects?

A patient receiving a vaccination

Asthma and Flu Vaccines

In general, people with asthma should get the flu vaccine, unless there is a reason not to, such as a history of Guillain Barre syndrome. For many years, there was also concern that people with egg allergies should not get the flu shot, but that no longer is the case. Talk with your healthcare provider, though, if you are still concerned.

So, why do so many people with asthma (roughly half) skip their annual flu shots? One reason is the concern that the flu shot could cause a worsening of asthma. Another is that people may not think they are at risk. Given the statistics, however, there is a good chance of contracting flu. Each year in the United States, there are between 9.2 and 35.6 million cases of influenza, 140,000 to 710,000 hospitalizations, and 12,000 to 56,000 deaths.

Some people are afraid to get the flu shot if a family member is immunosuppressed or on chemotherapy. But, this is not a problem with the injectable flu shot (the live attenuated flu vaccine, such as FluMist or Fluenz, should be avoided.) Conversely, failing to get a flu shot can put your loved ones at risk and vice versa.

So, we're left with two questions for discussion:

  1. How bad is it if you catch the flu when you have asthma?
  2. Are people with asthma more likely to have side effects from the vaccine?

Asthma and Influenza

People with asthma are no more likely to get the flu than people without asthma, but they are more likely to experience complications. Influenza can work both to trigger asthma symptoms in the first place and to worsen asthma symptoms you are already dealing with.

Catching the flu when you have asthma also raises your risk of pneumonia, especially if you are a child or older adult. Influenza is clearly more dangerous if you have asthma, but is the vaccine more of a problem as well?

Asthma Exacerbations: A Flu Vaccine Side Effect?

We have known that the inactivated flu vaccine—just one of the flu shots—does not increase asthma exacerbations in the two weeks following vaccination. At one time, it was even thought that the live attenuated nasal spray vaccine (FluMist or Fluenz) might be associated with wheezing. (The package insert warns against giving the vaccine to young children with asthma or anyone with recent episodes of wheezing.) More recent studies, however, seem to suggest that neither the flu shot or FluMist increase the risk of asthma exacerbations.

In one 2017 study following almost 400,000 flu immunizations given to children age two and older, the risk of asthma exacerbation was not increased for children who received either the inactivated influenza vaccine or the live attenuated influenza vaccine.

Another 2017 study that evaluated a population base of 6.3 million people came to a similar conclusion. It was found that while the live attenuated flu vaccine was used less than one percent of the time—and primarily for those with mild persistent asthma or intermittent asthma—it did not appear to increase the risk of asthma exacerbations. Based on this study, there was no increase in any type of respiratory adverse events for those receiving the live vaccine.

Despite these studies, some healthcare providers recommend that children and adults with asthma receive the flu shot vaccine rather than the nasal spray vaccine. The shot (specifically Flu-Zone High dose or the traditional flu shot rather than the intradermal shot) appears to be more effective than the nasal spray for those with serious medical conditions or the elderly.

Potential Side Effects

While some people with asthma will report mild symptoms, such as a sore throat, cough, and hoarseness after getting a flu vaccination, the virus in the inactivated vaccine is killed, so it can't give anyone the flu.

In contrast, the nasal spray flu vaccine is a live, though attenuated, virus. Even with the live, weakened form of the virus in FluMist, the virus is scientifically unable to cause the flu.

Moreover, just as with all medical treatments, there are potential side effects of the flu vaccine. Some of the minor flu vaccine side effects include:

  • Pain at the injection site
  • Fever
  • Malaise (just feeling poorly overall)
  • Myalgias (muscle aches)
  • Headache

Generally, these side effects occur within several hours to a few days after the vaccine and will resolve on their own.

Anaphylaxis (a serious allergic reaction) is a rare, but a life-threatening reaction that may occur after receiving a flu vaccination. While it occurs in only one out of one million vaccinations, you will need to see an allergist if this occurs or if you develop any worsening of your asthma after getting vaccinated.

Since anaphylaxis in response to the flu shot is very uncommon, we aren't certain whether it is more common in people with asthma. If you have any symptoms of anaphylaxis, such as shortness of breath, swelling of your mouth, tongue, or neck, wheezing, lightheadedness, or a feeling of impending doom, seek medical attention immediately.

A Word From Verywell

The flu vaccine is recommended for everyone with asthma who does not have a contraindication. Contracting the flu can be very dangerous for people with asthma, increasing the risk of pneumonia, hospitalization, or even death.

The flu vaccine itself, however, does not appear to be any more dangerous for people with asthma than those without the condition, though some healthcare providers recommend getting the flu shot rather than the nasal spray vaccine. Making sure family and friends of a person with asthma are vaccinated is helpful as well.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Chang K-H, Lyu R-K, Lin W-T, Huang Y-T, Lin H-S, Chang S-H. Gulllain-Barre Syndrome After Trivalent Influenza Vaccination in AdultsFrontiers in Neurology. 2019;10. doi:10.3389/fneur.2019.00768

  2. Asciak R, Balzan M, Buttigieg J. Predictors of seasonal influenza vaccination in chronic asthmaMultidisciplinary Respiratory Medicine. 2013;8(1). doi:10.1186/2049-6958-8-68

  3. Veerapandian R, Snyder JD, Samarasinghe AE. Influenza in Asthmatics: For Better or for Worse?Front Immunol. 2018;9:1843. doi:10.3389/fimmu.2018.01843

  4. Vasileiou E, Sheikh A, Butler C. Effectiveness of Influenza Vaccines in Asthma: A Systematic Review and Meta-AnalysisClin Infect Dis. 2017;65(8):1388–1395. doi:10.1093/cid/cix524

  5. Ray GT, Lewis N, Goddard K. Asthma exacerbations among asthmatic children receiving live attenuated versus inactivated influenza vaccinesVaccine. 2017;35(20):2668–2675. doi:10.1016/j.vaccine.2017.03.082

  6. Duffy J, Lewis M, Harrington T. Live attenuated influenza vaccine use and safety in children and adults with asthmaAnn Allergy Asthma Immunol. 2017;118(4):439–444. doi:10.1016/j.anai.2017.01.030

  7. Greenhawt MJ. Influenza vaccination in asthmatic patientsJournal of Allergy and Clinical Immunology. 2014;133(4). doi:10.1016/j.jaci.2014.02.009

Additional Reading

By Pat Bass, MD
Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians.