Covid-19 vaccine: everything you need to know

Coronavirus frequently asked questions

Updated 3 February 2021

How does the Covid vaccine work?

The Covid-19 vaccine works in the same way all vaccines do, by sending a signal to our immune system to create the antibodies that will fight the virus.

Up to 3 million lives are saved by vaccines worldwide per year, and thanks to vaccine roll-outs in the past, diseases like smallpox, polio and tetanus no longer exist or are very rare.

If enough people are vaccinated, viruses are prevented from spreading to people who can't have vaccines. For example, people who are ill or have a weakened immune system. This is called ‘herd immunity’.


What are the Covid-19 vaccines?

Two Covid vaccines have been rolled out in the UK: the Oxford/AstraZeneca vaccine, also known as the Oxford Vaccine or AstraZeneca vaccine, and the Pfizer/BioNTech vaccine, also known as the Pfizer vaccine or BioNTech vaccine. Both were created at an impressive speed due to large funding, resources and researchers.

The Oxford/AstraZeneca vaccine was tested on over 11,000 people and the Pfizer/BioNTech vaccine on 43,500 before being approved for public use. While they were developed far quicker than the average 8-10 years required for previous vaccines, both vaccines have met the strict standards of safety, quality and effectiveness set out by the independent Medicines and Healthcare products Regulatory.

Learn the difference between the AstraZeneca vaccine and the Pfizer vaccine.


What's in the Covid vaccines? (vaccine ingredients)

The Covid-19 vaccines do not contain chimpanzee cells, foetal tissues, animal products or eggs. Both the Pfizer/BioNTech vaccine and Oxford/AstraZeneca vaccine are suitable for vegans and vegetarians. 


What's in the Pfizer/BioNTech vaccine?

The Pfizer vaccine is an mRNA vaccine (messenger RNA), delivered in two doses. The active ingredient (highly purified single-stranded, 5’-capped messenger RNA ) sends instructions to the body’s cells to make specific viral proteins that can be recognised by the immune system to fight the Covid-19 virus. The Pfizer vaccine does not contain any live virus.

See the full Pfizer covid vaccine ingredients here.


What's in the Oxford/AstraZeneca vaccine?

The AstraZeneca vaccine is delivered in two doses, and contains a harmless, modified form of a different virus (an Adenovirus) as its active ingredient. An example of an adenovirus-based vaccine includes one type of BCG vaccine used against tuberculosis. The Oxford/AstraZeneca vaccine does not contain any ingredients that can cause Covid-19.

See the full AstraZeneca covid vaccine ingredients here.


What are the Covid vaccine side effects?

The most common Covid vaccine side effects include:

  • Slight pain in the arm at the site of injection.
  • Tenderness in the arm which usually lasts 1-2 days.
  • Some people will experience tiredness, headaches, general aches and mild flu like symptoms.

There is no evidence that the Covid-19 vaccine affects fertility or will change your DNA.

The Covid-19 vaccine has met the strictest safety standards and been declared safe for distribution, but will continue to be monitored by scientists who will report any rare or long-term side effects as and when they appear. 

For updates on Covid-19 side effects, see what to expect after your Covid-19 vaccine.


Which vaccine will I get?

Which vaccine you get will depend on availability, but you will only receive a vaccine that has been officially approved. The only vaccines currently available in the UK are Pfizer/BioNTech and Oxford/AstraZeneca. 


Is the vaccine permitted in my religious community?

Many religious communities openly support the Covid-19 vaccine, including The Muslim Council of Britain, who confirmed that all approved Covid-19 vaccines are safe to take, with all versions approved by The British Islamic Medical Association.


How does the vaccination process work?

Right now, the NHS is offering the Covid-19 vaccine to people who are most at risk from coronavirus. You'll get a letter, phone call, email or text inviting you for a vaccination appointment when it's your turn to have the vaccine.

When you do, you’ll need to have two doses of the vaccine and go to two appointments.

Read the experiences of different people who’ve had the Covid-19 vaccination here.

It’s important to remember the following:

  • You don’t need to contact the NHS to ask for the vaccine. You’ll be contacted when it’s your turn.
  • When the NHS does contact you, please attend your booked appointments.
  • It’s so important to continue to follow all the guidance to control the spread of the virus and save lives.

If you’re wondering ‘when will I be vaccinated?’, this handy calculator might help give you an idea.

Read more about Covid vaccination appointments

Find out how many people have had the Covid-19 vaccination, and learn more about mass vaccination centres


Do I need a vaccine, if I've already had Covid?

If you’ve had the illness, your body creates antibodies to fight off future infections. However, the jury is still out on exactly how long these antibodies last. Vaccination is the best way of protecting yourself and others against the virus in the long term.

How is the British Red Cross involved in vaccinations?

The British Red Cross has been supporting vaccination programmes for generations. Our volunteers and staff are helping at some of the first GP surgeries to roll out the vaccine.

We're also assisting with Covid-19 testing and flu vaccinations around the country. Lots of people turn up alone or feel nervous. We'll be welcoming them, explaining the process, and giving extra support to anyone who needs it in the safest possible way.

Read more in our Stories blog.

We are hugely grateful to everyone playing a role in the incredible task of rolling out the vaccination across the UK. While we must all continue to do our bit in keeping each other safe, there is reason to be optimistic for the future.


The information on this page is from the following sources: