This is a guest blog by Saffron Kular
In the current times, scientists, medics and the general public are living and breathing the idea of a vaccination. The world is striving to combat and survive a global pandemic – the corona virus. An infectious disease caused by a virus that replicates with the help of host cells. The virus causes individuals to experience respiratory problems, which explains many of its symptoms, such as shortness of breath. Right now, the world is asking how long before our lives return to normality, which in effect proposes the question of how long the world awaits a vaccination.
The development of a vaccine generally consists of 6 stages: exploratory stage, pre-clinical stage, clinical development, regulatory review and approval, manufacturing and quality control. Each stage differs in time scale.
The exploratory stage is research heavy. This stage aims to identify antigens, which are complementary to the antibodies which an individual’s immune system produces, which may contribute to preventing or treating the disease. The exploratory stage usually lasts between 2 to 4 years.
Stage 2, the pre-clinical stage, researchers will use tissue-culture or cell-culture systems and animal testing to test whether the identified vaccine will produce immunity. The development of the vaccine is not proceeded if this stage fails, which would mean that the tissue-culture or animals used, do not produce immunity. This stage gives researchers an idea of what metabolic processes or immune responses the vaccination provokes. Stage 2 is a vital stage as it has implications on the stages that follow, as it indicates a healthy dosage for stage 3. The pre-clinical stage of the development of a vaccination usually takes between 1 to 2 years- if you combine the exploratory stage with the pre-clinical stage, this usually takes between 3 to 6 years.
Stage 3, the clinical stage, is a three-phrase process. Phase I consists of administrating the vaccine to a small group of people, usually less than 100, around 20 to 80 healthy volunteers. The aim of phase I is to determine whether the vaccine and the dosage it was administered at is safe, and to learn more specifically, what immune responses the vaccine has on humans. Phase II includes delivering the vaccine to a larger sample size, usually hundreds of people, between 100 to 300 patient volunteers. Phase II is used to deliver more information to researchers about the safety, immunisation schedule and dosage, of the vaccine and runs for around 2 years. Phase III administers up to tens of thousands of vaccinations on individuals, in the aim to continue to measure and learn the effectiveness of the vaccination and wider side effects, which may not show when the vaccine is delivered to a smaller group and usually runs for around 3 years (on average). Stage 3, which consists of all 3 phases, usually demands 6 to 7 years of work.
The next stage that follows is the regulatory review and approval. If the vaccine passes the exploratory, pre-clinical and clinical stages, it’s developer must contact and submit a Biologics License Application (BLA) to the FDA. Stage 4 can take up to 4 years, where the researcher is applying for approval of their vaccine. After the final approval, the drug becomes available for physicians to prescribe.
The fifth stage that follows is the manufacturing stage. Drug manufacturers provide the infrastructure and equipment to mass produce quantities of the vaccination. The manufacturing stage roughly takes between 0.5 to 2 years.
The sixth and final stage of the development of a vaccination is, quality control. This includes, optional phase IV trials that the manufacturers can conduct after the vaccine is produced to test for the vaccine’s efficacy, safety and other uses that the vaccination can potentially be used for. In addition to the optional tests, quality control consists of: a follow up using VAERS (Vaccine Adverse Event Reporting System) and the Vaccine Safety Datalink. Both systems are designed to monitor the performance, safety and effectiveness of an approved vaccine. The last stage is ongoing and has a time frame for as long as the vaccination is available for, on average this is between 0.5 to 10 years.
So now that we’ve broken down the development of a vaccination into its six main stages, we can calculate on average, how long we wait for the result of an approved vaccine. The sum of the all the stages that were broken down above, comes to a maximum of 29 years and a minimum of 14 years. So, let’s clap for our NHS and keep our fingers crossed for our vaccination researchers, scientists and medics while we learn to survive a global pandemic.