This FAQ section contains our questions related to COVID-19 Vaccine efficacy/effectiveness.
To navigate to a different section of the FAQs, or go back to the main page, click on any of the links below:
- Back to main COVID-19 Vaccination webpage
- FAQ section on Vaccine safety and components
- FAQ section on Vaccine coverage and eligibility
- FAQ section on Fertility, pregnancy and breastfeeding
- FAQ section on Practical queries around getting the vaccine
- FAQ section on Operational plans
The vaccines work by making a protein from the virus that is important for creating protection.
The protein works in the same way they do for other vaccines by stimulating the immune system to make antibodies and cells to fight the infection.
It’s much safer for your immune system to learn this through vaccination than by catching the diseases and treating them.
Once your immune system knows how to fight a disease, it can often protect you for many years.
The MHRA have said this vaccine is highly effective, but to get a high level of protection you need to come back for the second dose – this is really important.
To ensure as many people are vaccinated as quickly as possible, the Department for Health and Social Care now advise that the second dose of the vaccines should be scheduled up to 12 weeks apart.
Full protection only kicks in around a week or two after that second dose, which is why it’s also important that when you do get invited, you act on that and get yourself booked in as soon as possible. Even those who have received a vaccine still need to follow social distancing and other guidance.
We expect these vaccines to work for at least a year – if not longer. This will be constantly monitored. More evidence is needed to understand whether a seasonal vaccination or booster dose might be needed.
Yes, for both vaccines trial participants included a range of those from various ages, immune-compromised and those with underlying health conditions, and both found the effectiveness of the vaccine is high through all the groups.
Although the vaccine was not tested on those with very serious immunological conditions, the vaccine has been proven to be very effective and it is unlikely that the vaccine will have no effect at all on you if you have ones of these conditions.
There may be a very small number of people with very complex or severe immunological problems who can’t make any response at all – but the vaccine should not do any harm to these individuals. If you meet these criteria may want to discuss the vaccine further with your specialist doctor.
Further advice and information can be found here.
The UK Chief Medical Officers have agreed a longer timeframe between first and second doses so that more of you can get your first dose quickly, and because the evidence shows that one dose still offers a high level of protection after two weeks – 89% for the Pfizer/BioNTech vaccine and 74% for the Oxford/AstraZeneca vaccine.
This decision will allow the NHS to get the maximum benefit for the most people in the shortest possible time and will help save lives.
Getting both doses remains important so we would urge you to return for your second vaccine at the right time.
There is no evidence currently that the new strain will be resistant to the vaccines we have, so we are continuing to vaccinate people as normal. Scientists are looking now in detail at the characteristics of the virus in relation to the vaccines. Viruses, such as the winter flu virus, often branch into different strains but these small variations rarely render vaccines ineffective. This is being continually monitored.
The important point for any vaccine is whether the MHRA approves it for use – if it does then that means it is a worthwhile vaccine to have and you should have it if you are eligible.
The Pfizer/BioNTech vaccine trials were carried out in the United States, Europe, Turkey, South Africa, and South America. The Oxford/AstraZeneca vaccine trials were in the UK, Brazil and South Africa.