Information for patients with Immune Thrombocytopenia (ITP) scheduled for Covid-19 vaccination. (Published 27th January 2022 but still current as of October 2022)
I have ITP. Can I receive the Covid-19 vaccine?
Yes. ITP is not a contra-indication to the Covid-19 vaccine.
Is it correct that thrombocytopenia can develop following Covid-19 vaccine?
In one study, it was estimated that approximately one new case of ITP occurred for every 100,000 doses of first AstraZeneca vaccine. The association was not observed with first Pfizer vaccine. Furthermore, there is no indication yet that thrombocytopenia following Covid-19 vaccine is any more common than after Covid-19 infection itself.
Another rare complication observed following the AstraZeneca vaccine was vaccine-induced immune thrombotic thrombocytopenia (VITT). This condition leads to blood clotting and low platelets, typically presenting 5-30 days post-vaccine. ITP was not identified as a risk factor for VITT, and VITT was almost exclusively reported after adenoviral vectors (AstraZeneca, Johnson & Johnson), rather than the mRNA vaccines (Pfizer, Moderna) now being offered in the UK.
If I have ITP, could my platelet count fall after the Covid-19 vaccine?
Some people with ITP will have a significant fall in platelet count after the vaccine (studies suggest about 1 in 15). In most cases, this will either resolve without treatment or respond to standard treatment. This effect does not appear to be specific to one particular type of Covid-19 vaccine and no other risk factors have been identified.
I am receiving immune suppression for my ITP, should I still have the vaccine?
Yes. The vaccine may give you less protection if your immune system is weakened by treatments such as rituximab, steroids or mycophenolate. For this reason, a 3rd Covid-19 vaccine has been offered, at least 8 weeks after the second, to those on such treatments, and subsequently a booster (4th) vaccine, from 3 months after the 3rd dose.
Can I prepare for my vaccine?
Yes. It is now recommended that your platelet count is checked 2-5 days after vaccination. Once you know your vaccination date, book a full blood count (FBC) check through your haematology department or GP. An additional FBC may be required if the platelet count is falling or bleeding symptoms develop. If you choose not to check the platelet count at 2-5 days, observe for unusual or increased bruising or bleeding and have your platelet count checked if this occurs.
If your platelet count is likely to be less than 50, ask for a thin needle (23 or 25 gauge) and press firmly at the injection site for 2 minutes without rubbing to reduce the chance of a bruised muscle.
My ITP presented or relapsed after Covid-19 vaccine. Can I have further Covid-19 vaccines?
The risk of a further platelet count drop appears higher in these circumstances, but the platelet count still does not fall in the majority of cases. You can have further Covid-19 vaccines, however discuss your individual circumstances with your haematologist first, and your post-vaccine platelet count should be monitored.
Patient information on behalf of the UK ITP Forum. Version 1 (27th January 2022). Authors: Drs Q Hill, V McDonald, N Cooper, S Pavord.