Everything we know about the Pfizer-BioNTech vaccine so far

Gloved hands holding vaccine vials

It's been a difficult year, but someone may have just switched the light on at the end of the tunnel.

That 'someone' (or rather 'someones') are the amazing scientists who have worked tirelessly to develop vaccines against the menace that is Covid-19.

If you've been keeping up with the news, you may be familiar with the name Pfizer-BioNTech.

Their Covid-19 vaccine was the first to be approved by UK regulators and the first doses have already started to be administered across the country.

This is a monumental achievement in scientific history due to the short period of time it took for the vaccine to be developed and tested.

Naturally, there are a lot of questions surrounding the safety, effectiveness and administration of the vaccine.

Questions naturally breed rumours, which aren't helpful in any situation, especially in a pandemic.

With so much confusion it can be hard to distinguish the facts from speculation, but this is what we are here for!

In this guide, we will explain some key facts about the new Pfizer-BioNTech vaccine that we know so far, including how it was tested, how it will be administered and who is eligible for it.

Who are Pfizer-BioNTech?

Pfizer-BioNTech is a collaboration between American drug company Pfizer and German biotechnology company BioNTech.

BioNTech is a small, but rapidly growing biotechnology company that has a focus on creating immunotherapies to help treat cancer.

Immunotherapies are a type of treatment that encourages the body's immune system to fight off cancer.

Pfizer is a large American pharmaceutical company that is responsible for many well-known medications and is one of the biggest suppliers for the NHS.

In 2018 they began their collaboration in order to develop mRNA-based vaccines to prevent influenza (flu) and in  March this year they agreed to work together to create their Covid-19 vaccine.

BioNTech is an industry leader in mRNA vaccine approaches and Pfizer has a large presence in the pharmaceutical industry and access to technology, resources and testing.

It has been a very successful partnership, as in December 2020 their Covid-19 vaccine was approved!

But, what is an mRNA vaccine and how can it help to prevent Covid-19?

How does the Pfizer-BioNTech Vaccine work?

The Pfizer-BioNTech Vaccine is known as an mRNA vaccine (or messenger RNA vaccine).

Vaccines generally work by triggering an immune response in the body.

This immune response involves creating an antibody to defeat the pathogen (germ) that causes a disease.

When we are first infected with a germ, such as a virus, that our body has never experienced before, it can take a while for our body to fight it by producing antibodies.

It is during this time that you will feel symptoms that the infection causes, whilst your body fights it off.

Once the body has created this antibody, it remembers it for the next time you are infected with this particular pathogen, so it can defeat it quicker - usually, before you even know you have been infected, so you won't develop symptoms.

Conventional vaccines tend to contain a weakened or inactive part of a particular microorganism (this is known as an antigen) which triggers the immune response in the body by creating antibodies.

Unlike being infected with an actual germ, you won't experience the symptoms of the illness it causes when your body triggers this immune response.

An mRNA vaccine is different from conventional vaccines as it doesn't contain a weakened or inactive part of the germ, instead, it contains a short segment of genetic material called messenger RNA.

This clever little substance provides instructions for a human cell to make a harmless version of the antigen (this is known as an immunogen).

This triggers the immune response by creating antibodies against the Covid-19 virus and remembers it, so if you come into contact with the virus in the future, your body will quickly fight it off without you developing symptoms.

Again, as this vaccine doesn't contain any part of the actual virus it poses no risk of infection.

How was the Pfizer BioNTech vaccine developed so quickly?

Pfizer and BioNTech had already launched a collaboration in 2018 to develop mRNA vaccine technologies for potential flu vaccines.

As the Pfizer-BioNTech vaccine is an mRNA vaccine, they already had the processes necessary to produce this vaccine in place, so they were able to quickly implement these processes to produce the Covid-19 vaccine.

Safety hasn't been compromised despite the short-time scale.

In addition to their own safety experts, the Pfizer-BioNTech Covid-19 Vaccine trial was overseen by an independent data monitoring committee (DMC) which is an outside group of experts who closely monitor patient safety and efficacy throughout the trial.

This DMC could recommend that the study was changed or stopped if there were any concerns regarding safety.

How was the vaccine tested on humans?

The human vaccine trial consisted of 43,448 participants who were 16 years or older.

21,720 participants received the Pfizer-BioNTech vaccine and 21,728 received a placebo.

They were given 2 doses 21 days apart.

What is a placebo?

Good question!

A placebo is a substance that has no therapeutic effect, which is used in clinical trials to test the effectiveness of treatments, vaccines and medicines.

It is used to test how effective the actual treatment, vaccine or medicine is.

This trial showed that partial protection from the vaccine appears to begin as early as 12 days after the first dose.

The results of the trial indicated that the vaccine was highly potent and well-tolerated irrespective of age, gender, ethnicity and pre-existing comorbidities (two or more diseases or medical conditions).

Who is eligible for the Covid-19 vaccine?

Currently, the Pfizer-BioNTech vaccine is being offered by the NHS to those who are most at risk from Covid-19.

At the moment, those who are eligible for the vaccine are:

  • Some people aged 80 and over who have a pre-existing hospital appointment in the next few weeks
  • People who live or work in care homes
  • Healthcare workers at high risk

You will need to be registered with a GP surgery and the NHS will let you know when it is your turn to have the vaccine.

It is important to NOT contact the NHS for your vaccination before you are invited.

How long will I have to wait between doses of the Pfizer-BioNTech vaccine?

The vaccine is an injection that is administered into the upper arm.

It involves 2 doses for complete immunity.

Initially, the doses were going to be administered 21 days apart.

However, the latest evidence suggests the 1st dose provides protection for most people for up to 3 months.

This has resulted in a delay between the two doses in order to ensure as many people as possible can have the vaccine.

The 2nd dose will now be administered 12 weeks after the 1st dose.

If you have already had your 1st dose and are due to have your 2nd dose after Monday 4th January, the NHS will contact you regarding when you will receive the 2nd dose of the vaccine.

If you were due to have your 1st dose after Wednesday 30th December, you will be given your 2nd dose 12 weeks later.

Does the Covid-19 vaccine cause any side effects?

Like all vaccines and medications, the Covid-19 vaccine can cause side effects.

However, most side effects are mild and shouldn't last longer than a week.

Mild side effects include:

  • Feeling tired
  • A sore arm where the needle went in
  • A headache
  • Feeling achy

You can take painkillers, such as paracetamol if you need to.

If you experience a high temperature, you may have coronavirus or another infection and should seek medical advice and a covid test, if applicable.

If you experience any severe symptoms or you have any concerns after receiving your vaccine, call 111.

Should I be vaccinated against Covid-19?

It is recommended that everybody that is eligible for the vaccine should receive it when they are notified by the NHS.

It may be possible to give this vaccine to pregnant women who are at high risk of serious complications of coronavirus or those who are breastfeeding, however, you need to speak to your healthcare professional before you have the vaccine.

It is VERY IMPORTANT to let NHS staff know if you have had a severe allergic reaction (anaphylaxis) BEFORE getting vaccinated.

You should NOT have the vaccine if you have ever had a serious allergic reaction to a previous vaccine.

If you do experience an allergic reaction to the vaccine, it usually occurs within minutes.

The staff who are administering the vaccine are trained to deal with allergic reactions and treat them immediately.

For more information about the Pfizer-BioNTech vaccine and covid vaccines in general go to:


Olivia Appleton - Medical Content Writer
James O'Loan - CEO & Superintendent Pharmacist
James O'Loan , CEO & Superintendent Pharmacist on 17 September 2021
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