Written by: Drugs & supplements

Stages of vaccine development

When there is an outbreak of novel diseases and pandemics, researchers and health medical personnel embark on finding a vaccine to protect human beings and animals from contracting viruses/bacteria. But before they make the breakthrough, the development involves various standard steps that are; exploratory stage, pre-clinical stage, and clinical development.

So what does each stage entails?

 Exploratory Stage

At this stage, basic scientific research is conducted in laboratories to identify, study, and understand the synthetic antigens that are acquired from pathogens. It focuses on studying the DNA cloning of the bacteria, viruses, and looking for the production of protective or treatment. The antigens could be weakened viruses, dead viruses or bacteria, and diluted toxins that are extracted from pathogens. Biotechnology firms research on improving the efficiency of the potential vaccine. This stage takes an average of 2-3 years. 

Pre-clinical stage

The preclinical step is mostly conducted by the private sector where cell- tissue culture systems and testing on animals are administered to check whether the prospective vaccine will have the desired immunity. It evaluates the ability of candidate vaccines to evoke the immunity of the animal. The animals are vaccinated with the trial vaccine and thereafter they are infected with the pathogen.

As a result, it gives the researchers an insight into what might happen when this vaccine is used on humans through cellular response. It also helps them to improve it, recommend an ideal starting dosage and the methodology of using the vaccine.

Clinical development

The next phase is clinical development that examines the effectiveness of the treatment on humans, any side effects, and its performance when compared to the others. However, it is a procedural activity that involves various stakeholders including health care professionals, doctors, data managers among other scientists. It contains four phases and they include:

Phase 1: 

It involves the administration of the vaccine to selected individuals between 80 to 100. This stage tests the safety of the vaccine, the response it provokes on the body any potential side effects and adequate dosage. Nevertheless, before testing in phase 1, vaccines can be tried on an optional trial on individuals between 10-15 to collect primary data. 

Phase 2

Involves hundreds of people (100-300) to provide more information and establish the efficiency of the drug therapeutic effect as well as its immunogenicity. 

Phase 3

 this stage tests a group of (100-300) to compare its effectiveness with other treatments. This phase is applied to random individuals in a double-blind experiment where one acts as a placebo test. 

Phase 4

This phase tests thousands of individuals to determine if the vaccine prevents disease, an infection from pathogens, and the release of antibodies to fight the pathogen. 

When a vaccine successfully passes through all the 4 stages, it is submitted to the relevant authority which inspects it, approves the production in mass quantities, and offers license. When a license is awarded, the manufacturing of the vaccine begins. The next phase is quality control and it takes place when distribution starts. It involves following up to monitor and verify if the drug is performing as it had been anticipated. 

Vaccine development is a complex process that involves procedural stages that takes some years. During each stage, the safety and effectiveness of the candidate vaccine are examined to determine its response to the immune system. A strong team of management, researchers, doctors, and biotechnology engineers are required to complete to make vaccine development successful. It is important to note that vaccine development is a costly venture and some samples do not succeed when they harm animals or humans during trial phases. 

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