The Pfizer/BioNTech coronavirus vaccine has been approved for use in the UK from the week commencing 6 December 2020. This means that the UK has become the first country in the world to approve the vaccine for widespread use. MHRA, the British regulator, says the jab, which offers up to 95% protection against Covid-19 illness, is safe for distribution.

To date, thousands of people have been given a COVID-19 vaccine and no serious side effects or complications have been reported. 

This is not the only vaccine which has been developed, or is under development. The World Health Organisation (WHO) is monitoring data from more than 200 vaccine trials.

In August 2020, the UK government announced new measures to support the development of safe COVID-19 vaccines for the UK. The measures included:

  • reinforced safeguards to support the Medicines and Healthcare products Regulatory Agency (MHRA) to grant temporary authorisation for the use of a new COVID-19 vaccine, provided it meets the highest safety and quality standards;
  • expanding the trained workforce who can administer COVID-19 and flu vaccines to improve access and protect the public; and 
  • clarifying the scope of the protection from civil liability for the additional workforce that could be allowed to administer vaccinations. 

What are vaccines?

The WHO describes vaccination in the following terms: 

Vaccination is a simple, safe, and effective way of protecting people against harmful diseases, before they come into contact with them. It uses your body’s natural defenses to build resistance to specific infections and makes your immune system stronger.

They go on to explain how vaccines work once administered:

Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications.

What is this COVID-19 mRNA vaccine?

The Centers for Disease Control and Prevention described this COVID-19 vaccine as a messenger RNA vaccine — or a mRNA vaccine. 

This type of vaccine does not put a weakened or inactivated germ into our bodies. Rather, mRNA teaches our cells how to make a protein — or even just a piece of a protein — that triggers an immune response inside our bodies. COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein”. This “spike protein” is found on the surface of the virus that causes COVID-19. The immune response to this — our body’s production of  antibodies — is what protects us from getting infected if the real virus enters our bodies.

It has been explained that a major advantage of RNA vaccines is that RNA can be produced in the laboratory from a DNA template using readily available materials, less expensively and faster than conventional vaccine production.

How has this vaccine been developed? 

This vaccine has followed all of the standard stages and processes of development. The vaccine had to complete each phase before progressing to the next. No stages of development were omitted. The phases include:

  1. Phase I — vaccine tested on a small number of people to check it is safe
  2. Phase II — safety tests in a greater number of people, and to look for signs the vaccine is producing the required response
  3. Phase III — a big trial, involving thousands of people, to prove it protects people

New York Times Vaccine Tracker has a very clear explanation of processes involved in the wider vaccine development processes. 

How can a vaccine be developed so quickly?

The idea that this vaccine has been developed so quickly perhaps underplays the impact of wider conditions on the development of a COVID-19 vaccine.  In particular, three conditions stand out:

  1. pre-existing knowledge and development of vaccines;
  2. financing/funding; and 
  3. accelerated trials.

Pre-existing knowledge and development of vaccines

The BBC reported the explanation of the speedy development of the Oxford vaccine was a result of what scientists already knew about this type of virus.  This is also the case for the Pfizer/BioNTech vaccine, where scientists understood the biology of the virus and how it behaved, and most importantly that they needed to build the designing the mRNA instructions for cells to build the unique “spike protein” into the mRNA vaccine.

All this prior knowledge and understanding of the virus would be useless without the capacity – and indeed, the money — to develop the vaccine. 


The scale of the global rates of COVID-19 infections and deaths , as well as the impact on the global economy, means that efforts to find a vaccine received unprecedented funds, and in a manner which reduced the usual level of bureaucratic issues of access to funds for scientific research. 

Accelerated clinical research

With an increase in funding and finance of the COVID-19 vaccine development, came an acceleration in the associated clinical research.  

Is it safe? 

The WHO explain:

“[T]here are many strict protections in place to help ensure that COVID-19 vaccines will be safe. Like all vaccines, COVID-19 vaccines should go through a rigorous, multi-stage testing process, including large (phase III) trials that involve tens of thousands of people. These trials, which include people at high risk for COVID-19, are specifically designed to identify any common side effects or other safety concerns.”

In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) have stated that a dedicated team of MHRA scientists and clinicians carried out a rigorous, scientific and detailed review of all the available data, which started in October 2020. This constituted what they called “a rolling review”.  A “rolling review” can be used to complete the assessment of a vaccine during a public health emergency in the shortest time possible.  It effectively works with and considers the data as it becomes available. 

To date, thousands of people have been given a covid-19 vaccine and no serious side effects or complications have been reported.