Why is AstraZeneca not used as a Covid booster - and can you have a Pfizer booster after an AstraZeneca jab?

With news of the Omicron variant, the rollout of the Covid Booster jab is being ramped up across the UK.

But the Oxford AstraZeneca, which was the most used vaccine for first and second jabs throughout the UK, will not be used for boosters.

Here’s why AstraZeneca is not used for booster vaccines and what this means for anyone who had the AstraZeneca vaccine.

What are Covid booster jabs?

Covid Booster jabs help to add an extra layer of protection against Covid.

With the rise of new variants including Delta and Omicron, there is concern they may slightly diminish the effect of vaccinations.

In Northern Ireland you are eligible for a booster jab three months after having your second Covid vaccination if you are over the age of 18.

The booster vaccine is currently being rolled out in aged phases, similar to the Covid vaccine.

Why is AstraZeneca not used for booster vaccines?

AstraZeneca was administered to millions across the UK, but it will not be used as a booster jab.

This is because according to the JCVI AstraZeneca is not an mRNA vaccine – unlike Pfizer and Moderna.

The AstraZeneca jab does not use mRNA technology and is instead made up of an adenovirus vector.

Adenovirus vectors work by using a version of the virus that is slightly different from the one targeted to create an immune response so we create antibodies that will then give us protection.

Whereas mRNA vaccines, trigger our bodies to make the SARS-CoV-2 spike protein and then break it down through a response from our immune system.

Even though the AstraZeneca is not suitable for a booster, it is still incredibly effective as a first and second vaccine, with a 63% rate of protection.

Can I have a Pfizer or Moderna booster jab if I received AstraZeneca vaccines?

Yes, you are able to have a Pfizer or Moderna booster jab if your first and second vaccines were AstraZeneca.

The JCVI have recommended a ‘mix-and-match’ approach to the booster roll-out, this means that you do not have to have the same vaccine as your first two jabs.

If your first two vaccines were AstraZeneca it is safe and effective to get a booster jab of either Pfizer or Moderna.

You can find out more about the Covid booster jab on the NHS website here.

More from the News Letter:

Northern Ireland booster jabs: How many people in Northern Ireland have had their Covid booster?

Covid Vaccine Passport NI: How they work, what are the rules and how to get a Covid Vaccine Passport