Covid-19 Vaccines and Immunity – What you need to know
As the Covid-19 vaccination programme in Cork and Ireland is being rolled out, we thought that it would be useful to take a look at how Covid-19 vaccines and immunity work to protect us from coronavirus. In this article, you can find out all you need to know about Covid-19 vaccines and immunity.
To see the latest national figures on the vaccination programme in Ireland visit the GeoHive dashboard (opens in new tab).
‘Most people will be protected from coronavirus after they’ve received both doses of a Covid-19 vaccine’ – HSE (Health Services Executive).
How do Covid-19 vaccines and immunity work to protect us?
Vaccines work by teaching our immune systems to protect us from viruses and diseases. It’s a lot safer for our immune systems to learn how to protect us against Covid-19 through the vaccination process than by catching the virus.
At this stage, scientists are not exactly sure how long immunity developed with vaccinations will last. However, many clinical trials are taking place around the world to establish how long we can expect immunity to last after having a vaccine.
How long does it take for Covid-19 vaccines to work?
Pfizer / BioNTech
- Estimated time for it to work: 4 to 5 weeks.
- Recipients should get the second dose of the Pfizer vaccine 3 to 4 weeks after the first dose. After the second dose, it takes 7 days for the vaccine to work.
Find out more about – Pfizer vaccine.
AstraZeneca
- Estimated time for it to work: 3 weeks. Time until best protection: 17 weeks.
- After receiving the first dose of the AstraZeneca vaccine, it takes 3 weeks for it to start to work. It’s expected that you will get your second dose 12 weeks after the first dose. The best protection is gained 15 days after receiving the second dose.
Find out more about – AstraZeneca vaccine.
Moderna
- Estimated time for it to work: 6 weeks.
- It takes 14 days from receiving the second dose for the Moderna vaccine to work. You should receive your second dose 4 weeks after the first dose.
What protection do Covid-19 vaccines and immunity provide?
Most people will be protected from coronavirus after they’ve received both doses of a Covid-19 vaccine.
Although there is a small chance that you may still contract Covid-19 after having a vaccine, being vaccinated can reduce serious symptoms. Clinical trials have shown that being vaccinated significantly reduces the chance of being hospitalised with severe Covid-19. Increasingly, new evidence is showing that vaccines can also reduce the spread of coronavirus.
The Health Service Executive (HSE), Department of Health and World Health Organisation recommend that you get your Covid-19 as soon as it’s offered to you.
It’s important to reiterate that, even after being vaccinated, we should continue to follow public health advice to stop the spread of Covid. For example, by continuing to follow social distancing, wear a face covering and washing hands frequently.
Find out more about – how to protect yourself and others from Covid-19.
What if you’ve got a weakened immune system already?
Covid-19 vaccines and immunity may not work as well for you if you have a weakened immune system and/or you take immunosuppressive medicines. However, there is no additional risk involved in getting the vaccine.
Find out more about – Covid-19 and weakened immune systems.
How have the Covid-19 vaccines been tested?
Pfizer/BioNTech COVID-19 vaccine
The Pfizer/BioNTech vaccine has been tested on people aged 16 upwards. The Pfizer vaccine protected 95% of people from getting Covid-19 in clinical trials. Testing also showed that the vaccine works well for adults of any age.
Find out more about – Pfizer vaccine.
AstraZeneca
The AstraZeneca vaccine has been tested on people aged 18 upwards. During clinical trials, the vaccine protected 60% of people from getting Covid-19 and 100% of people from being hospitalised with severe illness.
Trials are continuing to confirm how well the AstraZeneca vaccine works with people aged over 70. Until those results are in, the AstraZeneca vaccine will not be given to those over 70 in Ireland.
New evidence from England shows the AstraZeneca vaccine provides:
- protection of 76% after the first dose, which lasts up to 12 weeks.
- protection increases to 82% when the second dose is given, after 12 weeks.
New evidence from Scotland shows:
- the risk of being admitted to hospital with severe COVID-19 is reduced by 94%, 4 to 5 weeks after 1 dose of the AstraZeneca vaccine.
Find out more about – AstraZeneca vaccine.
Moderna Covid-19 Vaccine
The Moderna vaccine has been tested on people 16 years old and upwards. This vaccine protected 94% of people from getting Covid-19 in clinical trials. Testing shows that the vaccine works well for adults of any age.