Overview - AstraZeneca COVID-19 vaccine

Vaccines are the best way to prevent infectious diseases. They teach your immune system (your body's natural defences) how to protect you from a specific virus.

The official name of AstraZeneca's COVID-19 vaccine is 'Vaxzevria'. But most people call it 'AstraZeneca'.


You will need 2 doses of the AstraZeneca COVID-19 vaccine.

You should get your second dose 4 to 12 weeks after your first dose.


Vaccines teach your immune system how to protect you from diseases.

You will have the best protection 15 days after your second dose of the vaccine.

Read more about immunity after the AstraZeneca COVID-19 vaccine


The AstraZeneca COVID-19 vaccine was developed in line with international standards of safety.

It has been tested with thousands of people as part of clinical trials.

Read more about the safety of the AstraZeneca COVID-19 vaccine

Side effects

Like all medicines, vaccines can cause side effects. Most of these are mild to moderate and short-term.

Not everyone gets side effects.

Read more about side effects after the AstraZeneca COVID-19 vaccine

Which vaccine is best

All COVID-19 vaccines give you good protection from severe illness from COVID-19 when you are fully vaccinated. The HSE only uses a vaccine if it meets the required standards of safety and effectiveness.

Pfizer/BioNTech or Moderna are the recommended vaccines for people under the age of 50. This is because of the very rare risk of unusual blood clots with low platelets in people under 50 who get the AstraZeneca or Janssen vaccines.

If you are pregnant

If you have not been given a vaccine yet, you will be offered a different COVID-19 vaccine to the AstraZeneca vaccine.

If you have already had your first dose of the AstraZeneca vaccine, you should still get your second dose.

You will be at greater risk of severe illness if you do not get your second dose.
Being fully vaccinated will reduce the chance of you becoming very unwell.

Read more about COVID-19 vaccines in pregnancy

If you are breastfeeding

There is no known reason to avoid the vaccine if you are breastfeeding.

Read more about COVID-19 vaccines if you are breastfeeding

This content was fact checked by vaccine experts working in Ireland.

Last updated: 5 August 2021 at 4:15pm

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