Every drug that calms an overactive immune system also, to some degree, calms the part of it that fights infection. The size of that effect is smaller than most people fear, and it is entirely manageable — but only if you know what to do in advance rather than working it out during a fever.
How much extra risk
For most people on methotrexate or a similar drug, the increase in serious infection is small. Biologic treatments carry a somewhat greater increase, varying by drug. Steroids, particularly at higher doses and over longer periods, contribute more than people expect and more than the biologic in many cases.
Set against that, uncontrolled inflammatory disease itself raises infection risk. Untreated disease is not the safer option.
Vaccines you should have
Inactivated vaccines are safe on immunosuppressive treatment. They may produce a slightly weaker response, which is a reason to have them, not to skip them.
- Influenza, annually
- Pneumococcal, according to current national guidance
- COVID-19, as advised
- Hepatitis B, where there is a risk factor
- Shingles, using the non-live recombinant vaccine, which is suitable for people who are immunosuppressed
Ideally these are given before immunosuppression starts, or at least two weeks before, since the response is better. In practice, most are given during treatment and that is perfectly reasonable.
Vaccines to avoid
Live vaccines are generally avoided while on significant immunosuppression, because a weakened live organism can occasionally cause disease in someone whose immune system is suppressed. These include the older live shingles vaccine, yellow fever, oral typhoid, and MMR.
If you are planning travel that requires a live vaccine, raise it several weeks ahead. There is often a workable route, but it needs planning.
Household members can have live vaccines normally. There are a small number of sensible precautions after a child's rotavirus vaccine, which the clinic can explain.
Screening before treatment starts
Before biologic treatment, screening for tuberculosis and hepatitis B and C is standard. In India this matters particularly: latent tuberculosis is common, and biologic treatment can reactivate it. Screening is a chest X-ray and a blood test, and where latent infection is found, treatment for it is given before or alongside the biologic. This is not a formality and it is not optional.
Holding a dose
Hold your methotrexate or biologic dose while you have a significant infection or are taking antibiotics for one, and restart once it has resolved. This does not apply to a mild cold without fever.
Do not hold steroids. That is the opposite of what is needed during illness, and the dose may need to be temporarily increased instead.
If you are unsure whether an infection counts, ring the clinic. It is a two-minute conversation.
What should not be waited out
- Fever, particularly above 38 degrees, or a fever with shaking chills
- Breathlessness, or a cough producing coloured sputum
- A cough lasting more than three weeks, weight loss, or drenching night sweats — these need tuberculosis excluded
- A rapidly spreading area of hot, red skin
- A hot, swollen, exquisitely painful joint, which can be joint infection and needs assessing the same day
- Confusion, or being unable to keep fluids down
Steroids in particular blunt the usual signals, so an infection can be well advanced before it feels serious. When in doubt, be seen.
Practical measures that help
Keep vaccinations current. Attend for your monitoring blood tests. Practise good food and water hygiene, which matters more when travelling. Treat dental infections promptly. And carry a note of your medicines, so that any doctor treating you in an emergency knows what you are on.
None of this needs to dominate your life. It is a short list of sensible habits and one clear rule: a fever on immunosuppressive treatment is worth a phone call, not a wait-and-see.
This article is general information and does not replace a consultation.