How are vaccines researched and manufactured?

The UK has a longstanding reputation for vaccine development. The first vaccination ever developed was in the UK by Edward Jenner in 1796 for smallpox.1

Vaccines are checked at every stage as they are researched, tested and manufactured. Their safety and effectiveness continues to be monitored for as long as they are in use.

The standard for testing and monitoring vaccines is higher than it is for most other medicines, because they are one of the few medical treatments given to healthy people.2

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How are vaccines researched?

This short video explains the process of research and development for vaccines.3

The steps are:

 

1

Discovery and pre-clinical:

The disease is researched to identify a possible vaccine, which is tested to check it meets safety standards.

2

Manufacturing:

The manufacturing process is developed, to ensure production of identical, high-quality vaccines at a large scale.

3

Clinical trials:

The vaccine is tested for safety and effectiveness, starting with small numbers of volunteers and building up to thousands.

4

Licensing:

The vaccine is evaluated by the independent regulator. If approved, a license is granted to make it available for use.

5

Quality testing:

Vaccines are tested at every stage of production to make sure they meet quality and safety standards consistently.

6

Safety monitoring:

The vaccine is evaluated by the independent regulator. If approved, a license is granted to make it available for use.

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How were vaccines for COVID-19 developed so quickly?

A number of things came together to allow COVID-19 vaccines to be developed quickly, while keeping to the normal, extremely high quality and safety standards.

  1. Research on vaccines for SARS/MERS had already been going on for years, and when China released genetic information on SARS-COV-2, it helped to focus the research.
  2. There was a huge amount of extra manpower and a lot of collaboration put in to prioritise these vaccines.
  3. Steps that are normally done one after the other happened side by side.  

All this meant that COVID vaccines were developed quickly, while keeping all the normal processes and standards.4

How are vaccines manufactured once they are approved for the public?

This short video explains the process of research and development for vaccines.5

The steps are:

 

1

How does manufacturing begin?

Raw materials like glucose, bacteria and trace minerals form the basis of the vaccine.

2

What is the purification process?

The active ingredient is created, separated and purified by removing waste materials and by-products.

3

How is the vaccine packaged?

The formula is put into sterilised vials or syringes for distribution.

4

What is batch testing?

Checks are conducted on every batch of vaccine produced. This important stage is where the vaccine undergoes quality, identity and sterility tests.

5

At what point is the vaccine released?

Only after a Qualified Person has reviewed all the data from the manufacturing and testing process. The vaccine is then certified that it meets quality, safety and efficacy criteria.

6

How is the vaccine transported?

Directly from the factory under controlled conditions – these vary by vaccine – so that it remains in the same condition as it left.

Monitoring of vaccines

Vaccines must be monitored and regulated throughout their lifetime. The pharmaceutical company has a duty to monitor the vaccine and make sure it performs safely for as long as it’s on the market. This process is called pharmacovigilance and it helps inform regulators about previously unknown side effects.
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Collecting this data provides a better understanding of what a vaccine can do and how it might be used to treat other conditions or unlock basic science to progress new treatments for future generations.

References

 

  1. OHE. Value of Vaccines report (OHE, July 2020)
  2. Oxford University, Vaccine knowledge project, 2018
  3. Vaccines Europe, How are vaccines developed, WHO, Regulation and quality control of vaccines
  4. The Lancet, Carving a path towards a COVID-19 vaccine, BBC, The Oxford vaccine, how did they make it so quickly?
  5. Vaccines Europe, How are vaccines produced?, National Institute for Biological Standards and Control,Independent batch release testing at the NIBSC

Last modified: 12 November 2025

Last reviewed: 12 November 2025