Background

There has been considerable confusion in the media, and also in some health professional circles, about which people cannot have COVID-19 vaccines. In New Zealand, only the Pfizer/BioNTech messenger RNA (mRNA) vaccine is currently available, but two adenoviral vector vaccines (Janssen and Astra Zeneca) have been approved by Medsafe. Some confusion may have arisen because vaccines which include a live but weakened virus - like measles, mumps, rubella (MMR) and the shingles vaccine (containing the varicella-zoster virus) - cannot be given to people with very compromised immune systems.

The Pfizer/BioNTech COVID-19 vaccine does not contain any virus and it is impossible to catch COVID-19 from it. This means that like other inactivated vaccines, almost everyone can have at least one dose of this vaccine. This includes people who are pregnant or breastfeeding, have medical conditions, or are receiving treatments that weaken the immune system such as certain immunodeficiencies, cancer, HIV and some autoimmune diseases.

So, is there anyone who cannot have the Pfizer/BioNTech COVID-19 vaccine?

The Pfizer/BioNTech COVID-19 vaccine has an excellent safety profile and there are only a handful of eligible people (fewer than 100) in Aotearoa who cannot receive it at all. The list of reasons why the Pfizer/BioNTech COVID-19 vaccine may not be suitable is short:

Before the first dose:

• History of severe allergic reaction (anaphylaxis) to an ingredient of the vaccine. This is very rare, and only applies to previous anaphylaxis to a stabiliser in the vaccine called polyethylene glycol (PEG). However, this is often unclear as problems with PEG most commonly occur after having it by mouth and there may not be any problem with having it in a vaccine. Cases like this require expert assessment by an immunology specialist.

After problems with the first dose:

• People who had a severe allergic reaction (anaphylaxis) after the first dose – this typically occurs within 15 minutes of receiving it and is the main reason for waiting after vaccination. Even when suspected anaphylaxis has occurred after the first dose, increasing experience now shows that many people can be revaccinated safely in a specialist immunology clinic setting.

• Those who had myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the lining around the heart) after their first dose of this vaccine. Myocarditis or pericarditis after the vaccine is rare. Diagnosis requires special tests and often assessment by a heart specialist.

• Very occasionally, some people have strong reactions after their first dose that are more severe and/or last for longer than anticipated. It is important that these adverse reactions are reported to CARM so that Medsafe can continue to monitor vaccine safety. In these cases, a postponement of the second dose or a longer spacing between doses may be advised.

What about those with other allergies?

• Some people develop delayed allergic type symptoms, such as hives and other skin rashes. These people can be revaccinated.
• People with a history of allergy to foods and venom can be vaccinated.
• People with a history of severe immediate allergic response (anaphylaxis) to another vaccine or multiple drugs can receive this vaccine but are asked to wait to be observed for a little longer after vaccination.

Find more information on severe allergic reactions after immunisation, and the contents of Comirnaty (Pfizer/BioNTech) here.

An IMAC fact sheet for health professionals on this topic is also available.

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