Vaccine Development

The development and production of the COVID-19 vaccine have shocked many of us by the speed at which it had taken. Vaccines usually take years to develop and produce however, the COVID-19 vaccine only had taken 8-9 months which has caused concerns for many people. The main concerns that many had was whether the vaccine was safe and the potential long term side effects.

Vaccine development processes

Even though the COVID-19 vaccine had taken less time to develop, the researchers insisted that vaccines are safe and have been tested thoroughly using the usual testing stages to ensure vaccines are tested and safe for mass vaccination. Below I will summarise the key stages to develop and test a vaccine.

Exploratory Stage

Academic and governmental scientists research natural or synthetic antigens to help prevent or treat a disease.

Pre-Clinical Stage

Tissue culture or cell culture systems and animal testing are used to assess the vaccine and its ability to provoke an immune response. Animal subjects such as mice and monkeys are used to gain an understanding of any cellular responses that might be expected in human beings. It will indicate a safe starting dose for the next stage.

IND Application

At this stage, a private sponsor applies an investigational New Drug (IND). The sponsor would describe manufacturing, testing processes and describes the proposed study. Once the IND application has been approved, the vaccine is then subject to three phases of testing.  

Phase 1 Vaccine Trials

Phase 1 involves testing a small group of adults, which is usually between 20-80 subjects. Phase 1 test assess the safety of the vaccine and determines the type and extent of the immune response that the vaccine provokes.

Phase 2 Vaccine Trials

Phase 2 involves a larger group of several hundred individuals participants. Some of the individuals may belong to a group at risk of acquiring the disease. These trials are randomised and well-controlled.  This testing phase will involve a placebo group to help identify if the vaccine is working or it's just individuals who believe that they have given the vaccine.

Phase 3 Vaccine Trials

Upon the success of Phase 2 trials, Phase 3 moves into a larger group that involves thousands to tens of thousands of people. Phase 3 testing is randomised and involves an experimental vaccine being tested against a placebo. The main objective at this stage is to assess the safety of a larger diverse group. Certain rare side effects may have not surfaced in the small group of subjects in the earlier phases.

During this phase Vaccine efficacy tests as well, these factors include:

Does the vaccine prevent disease?

Does it prevent infection with the pathogen?

Does it lead to the production of antibodies or other types of immune responses related to the pathogen?

Approval and Licensing

Upon a successful phase 3 trial, the vaccine developer will submit a Biologics License Application and get their factory inspected where the vaccine will be made and gain approval of labelling of the vaccine.

How was the COVID-19 vaccine developed so quickly?

The main factor that enabled the COVID-19 vaccine to be quickly developed is the urgency of the global pandemic; thousands of deaths were recorded worldwide. The global outcry of a vaccine motivated companies and politicians to dedicate all resources to the development of a viable vaccine. Advancement in technology has allowed scientists to produce a DNA sequence of the new unknown virus and publish information to the wider science community at breakneck speed. The instant availability of information about a new unknown virus enabled the science community to react instantly and start developing a vaccine. Our knowledge of viruses and how they work have improved over years of research, which has allowed us to identify the proteins and start testing the correct vaccine delivery system.

Summary

Vaccine development requires a lot of time and resources to development but the vaccine development process is thorough and strict. The number of trials will help identify any short or long-term effects. When developing a new vaccine they have to match certain criteria at each trial stage to proceed further along the trial development process.

Even though the COVID-19 vaccine has been developed, produced and rolled out within several months, the severity of the pandemic has motivated scientists and politicians to focus all resources on its development. The World Health Organisation has a process in place once a new strand of an unknown virus is found. With today’s technology scientists can identify and share information on the new virus within minutes which will enable scientists around the world to start developing a vaccine.

The understanding of how vaccines are developed and tested before rollout has ensured me that the vaccine has been thoroughly tested. Even though the vaccine is being rolled out, health officials continue to monitor for any adverse side effects. As the vaccine rollout continue to progress within every country. Hopefully, the vaccines will bring back some normality in daily life. However, we must be cautious as new variants are popping up as the virus continues to evolve and infect populations.