Rheumatoid arthritis (RA) is an autoimmune condition that causes inflammation, swelling, and pain. It can also affect the immune system. As a result, people with RA are more susceptible to viral illnesses, such as influenza, or flu. They are also at greater risk of flu-related complications.

This information comes from the Arthritis Foundation (AF).

The viruses that cause flu are different from the viruses that cause colds. Unlike most colds, the flu can lead to serious illness.

For people with RA, the benefits of getting the flu vaccine often outweigh any potential risks.

In this article, we take a closer look at the flu vaccine and RA, including the vaccine’s benefits, effectiveness, and potential side effects. We also discuss other ways to protect against viral illnesses.

A woman with rheumatoid arthritis preparing to receive a flu vaccine. A medical professional is sterilizing the skin on her arm while holding a needle in the other hand.Share on Pinterest
Alfredo Hernandez Rios/Getty Images

Yes, people with RA can get the flu vaccine. The Centers for Disease Control and Prevention (CDC) recommend that everyone aged 6 months old or older receive an annual flu vaccination.

The rare exceptions to this include those with severe allergies to the vaccine or any of its ingredients. People can check the ingredients of the vaccine they will receive with a doctor or healthcare facility.

People with RA have weakened immune systems. As a result, they are at higher risk of getting the flu and developing flu-related complications.

Some of the potential complications of the flu include:

An older 2012 study involving over 80,000 participants found that people with RA developed flu more frequently than people without RA. Those who did develop flu had a 2.75-fold increase in complications compared with the control group.

However, evidence shows that the flu vaccine reduces the risk of severe illness. A 2018 study found lower rates of flu-related hospitalizations among people with RA who had received the flu vaccine, particularly among older adults.

It is important to get the flu vaccine each year, as the viruses that cause flu change over time. Scientists match the vaccine with the viruses that are circulating during each flu season, in order to give people the best protection.

The effectiveness of the flu vaccine varies depending on several factors, such as the types of viruses that are circulating at a given time and a person’s individual response to the vaccine.

The CDC conducts annual flu vaccine effectiveness studies. Current data show that during seasons when the vaccine is matched well to common flu viruses, it reduces the risk of contracting flu by 40–60%.

Generally, flu vaccines are more effective against influenza B and A(H1N1) than they are against influenza A(H3N2).

Even if a person contracts a flu virus after receiving the vaccine, the symptoms may be less severe.

A 2018 study showed that among hospitalized people who received the vaccine but who still developed flu, there were:

  • fewer deaths
  • fewer people in intensive care units (ICUs)
  • shorter ICU stays
  • shorter hospital stays

Research suggests that the flu vaccine typically does not cause RA flare-ups.

In an older 2006 study, there was no difference in the clinical picture of RA among people who received the flu vaccine and those who did not.

A 2019 study showed no significant connection between flu vaccination in people with RA and doctor consultations for symptoms of an RA flare-up.

However, contracting a viral infection, such as flu, can trigger a flare of RA symptoms, according to the AF. For this reason, it is typically better to prevent infections whenever possible.

People can develop temporary side effects from the flu vaccine. The most common include:

If a person has a phobia of needles or blood, the vaccination may also cause fainting. Healthcare professionals can help if this occurs.

Rarely, flu vaccines can cause serious allergic reactions. Symptoms of this typically develop between a few minutes and a few hours after vaccination and include:

If any of these symptoms develop, a person should immediately call 911 or the number of the nearest emergency department.

There is very little likelihood that people who have received the flu vaccine will develop Guillain-Barré syndrome.

The CDC estimates that, for every 1 million people who receive the flu vaccine, only 1 or 2 people may develop the syndrome. This is much lower than the number of people who will develop flu-related complications.

Typically, people taking RA medications can get the flu vaccine. However, research on how different kinds of RA drugs may interact with the vaccine is ongoing.

In an older 2006 study, neither immunosuppressive therapies at typical doses nor any kind of disease-modifying antirheumatic drugs (DMARDs) negatively affected the humoral response to the flu vaccine. This included methotrexate, infliximab, and etanercept.

However, a 2017 clinical trial found that temporarily discontinuing the DMARD methotrexate helps improve flu vaccine effectiveness.

People can speak with a rheumatologist about how their RA medication may affect the flu vaccine.

In addition to getting a flu vaccine, people can take other steps to reduce the risk of contracting a flu virus.

The CDC recommends:

  • avoiding close contact with people who have the flu
  • avoiding touching the eyes, nose, or mouth
  • regularly washing the hands with soap and water
  • using alcohol-based hand sanitizer when running water is not available
  • cleaning and disinfecting surfaces that people touch often, such as door handles and light switches
  • maintaining or developing healthy habits, such as getting enough sleep, eating a balanced diet, and managing stress

To prevent transmission to others, everyone should try to cover coughs and sneezes with the inside of the elbow and to stay at home if they start feeling sick.

People with RA are at greater risk of developing flu and flu-related complications. Getting a flu vaccine is a safe way to reduce the risk of flu in people, including those who take RA medications.

It is advisable for people with RA to discuss flu vaccination with a doctor to learn about its benefits and potential side effects.