Is the COVID-19 vaccine safe for people with Crohn’s or Colitis?
As with many vaccines, it is possible you may get some side effects after the COVID-19 vaccine. The most common ones include:
- A sore arm where you had the vaccine
- Feeling tired
- Headaches
- Muscle aches
These effects are usually mild and go away within a few days. People with Crohn’s and Colitis have similar side effects to the rest of the population, and these are usually mild. This is the case no matter what treatments you may be taking.
COVID-19 vaccines are not live vaccines (they do not contain any live virus). This means there’s no risk of it causing infection with COVID-19.
There is no evidence that having the COVID-19 vaccine will cause a flare-up in your Crohn’s or Colitis. A few people have reported having a flare-up soon after having the vaccine. But these numbers are similar to people who have not been vaccinated.
If you feel you have had a side effect from the COVID-19 vaccine, you can report it via the MHRA Yellow Card reporting site. Speak to your IBD team too if you’re concerned.
Does having Crohn’s or Colitis affect how well the vaccine works?
Having Crohn's or Colitis does not make the vaccine any less effective. If you’re on a 5-ASA medicine or no medicine at all, the vaccine should work as well as for someone without Crohn's or Colitis. However, being on certain immunosuppressant medicines may make the vaccine work less well.
Vaccines work by ‘tricking’ your immune system into launching an attack against a virus before you have been exposed to it. If you are then exposed to the virus later on, your body is already prepared and protects you from getting ill. If you are taking immunosuppressant medicines, your immune system might not respond as well to the vaccine as other people’s.
Evidence from major studies such as CLARITY and VIP shows that people taking anti-TNF medicines, such as infliximab, or the JAK inhibitor medicine tofacitinib have a reduced response to the COVID vaccine. This can mean:
- They produce fewer antibodies (proteins produced by your immune system in response to an infection)
- There is a reduced T-cell response (these are types of cells that fight infection in your immune system)
- They have a greater number of ‘breakthrough infections’ (infection with COVID-19 after vaccination)
- Their protection after vaccination reduces faster over time
We can’t be sure yet whether other immunosuppressants have a similar effect. But there are promising results that azathioprine, ustekinumab and vedolizumab did not reduce vaccine response in studies.
If you were taking immunosuppressant medicines when you had your first (primary) COVID-19 vaccines, you should have been offered an extra (third) dose. This extra dose should help to improve your protection.
Having a reduced response to the vaccines does not mean you should stop your treatment before getting vaccinated. Stopping treatment can lead to a flare of your Crohn's or Colitis, which puts you at greater risk from serious complications of COVID-19.
Even if the COVID-19 vaccine works slightly less well for you, it will still offer greater protection than not having the vaccine. You may also be eligible for vaccine boosters. These help to improve your immune response against current strains (‘variants’) of COVID-19.
Seasonal Covid-19 booster vaccines
COVID-19 vaccines are normally given seasonally. If your NHS record suggests you may be eligible for a seasonal COVID-19 vaccine, the NHS will contact you with information on when and where you can get your booster.
Depending on where you live in the UK, you can get information about current COVID-19 booster programmes, including who is eligible, from the following places.
Latest seasonal update - Spring 2025
Fewer people are eligible for the spring COVID-19 booster than previous boosters. The spring booster will only be offered to people who are:
- Immunosuppressed and aged over 6 months
- Aged 75 years and over
- Living in a care home for older adults
Reviewing current guidelines
The COVID-19 variants in circulation are under constant review. If a new, more infectious, or serious variant were to emerge, people at higher risk may be offered additional boosters.