A patient due a glaucoma surgery was asked to use a steroid eye drop (maxidex) continuously until the day of the procedure. The patient has had her two Pfizer/BioNTech jabs and was due a Pfizer/BioNTech booster in some few days. The woman was worried after reading a leaflet on vaccine that patients on steroids may not be suitable for that jab. The patients wanted to know whether she should opt for the AstraZeneca or Modena jab instead.
So, the questions are, can taking steroid in any form be a contraindication for having the Pfizer/BioNTech jab or any of the other recommended jabs? Secondly, what route of steroid administration is most likely to affect the efficacy of the jabs?
The information of concern is a leaflet on the UK government website (and possibly other countries too) under “Warnings and Precautions”
“You have a weakened immune system, because of a disease such as HIV infection or a medicine such as corticosteroid that affects your immune system”
So, the patient was right to be concerned and to seek an alternative vaccine (which would probably have similar warnings).
How could steroid affect the vaccine?
Steroids are powerful anti-inflammatory drugs that work to dampen immune response towards perceived external or internal enemies to the body. One example is the drug dexamethasone, which is the only licensed drug for treating covid19. It has been proven to reduce death in more severe covid19 cases. It is not an antiviral drug, so it does not kill or inactivate the virus, however, its effectiveness is mainly due to interfering with the aggressive immune response to the virus, which sadly in some cases lead to extensive inflammation, tissue damage and subsequent organ failures.
Steroids comes in different types and forms and can be consumed through different routes. Each route offers a unique pharmacokinetic process and would determine their efficacy or otherwise.
The quantity of steroid in one drop of an eye drop (the space on the eye is too small to contain more than one or two drops) may be too small to have any systemic effect, which in this case is the lowering of the immunity to elicit robust immune response to the vaccine.
This would be indifferent whether the patient had AstraZeneca or Modena vaccine.