The announcement by Sechenov First Moscow State Medical University that its researchers have completed world’s first human clinical trial of a vaccine for novel coronavirus (SARS-CoV-2) that caused the COVID-19 pandemic has understandably created anticipation among experts and governments across the world.
Chennai:
Though it is a significant breakthrough, there, however, are more steps to be completed before an effective vaccine hit the market
VACCINE DEVELOPMENT IN THE MIDST OF A PANDEMIC
Typically, the development of a vaccine can take up to 10 years due to the laborious process behind it. But considering the global urgency to bring the pandemic under control, COVID vaccine development is being compressed and fast-tracked. Experts expect the vaccine to be ready in 12 to 18 months
HOW DOES A VACCINE WORK
WEAK GERMS INJECTED
Traditionally, vaccines contain the same germs, either killed or weakened, or part of the germ that causes the disease
ANTIBODIES CREATED
They stimulate your immune system to produce antibodies, as if you were exposed to the germ
IMMUNITY DEVELOPEDW
After getting vaccinated, one develops immunity to that disease without having to get it first
STAGES OF DEVELOPMENT
Pre-clinical phase
- Normally occurs before human testing can begin
- Collects data to support feasibility and safety
- Involves repeated non-human testing
- Evaluates toxic and pharmacological effects
Clinical phase I
- Small study on healthy persons
- Evaluates safety and immune response at different doses
- Typically takes 1-2 years, but for COVID-19 trials, expected to take only 3 months
Clinical phase II
- Studies 100s of people
- Further evaluates safety, assesses efficacy, and informs optimal dose and vaccine schedule
- Typically takes 2-3 years, but expected to take 8 months for COVID-19 trials
Clinical phase III
- Studies 1000s of people
- Further evaluates safety and efficacy
- Typically takes 2-4 years, but may be combined with Phase II
REGULATORY REVIEW
- Government agency reviews trial data and licensing application information before approval
- Can happen while manufacturing has started
- Typically takes 1-2 years, but expedited to take only a few months
Clinical phase IV
- Post-approval studies that monitor effectiveness in real-world conditions
- Testing begins after the vaccine has been released to the public
MANUFACTURING
Developers will try to ensure that enough of a vaccine is ready by the time it is approved. But if the approval doesn't come through, the manufacturer will lose resources. So the risk is directly proportional to the amount of vaccine produced. Let's look at different scenarios to be presented before us
NON-IDEAL: Developer manufactures mass quantities but does not get approval, leaving the public without a vaccine and resources put into manufacturing lost
GOOD: Developer gets fast approval but has not manufactured enough of a vaccine to distribute in mass quantities. The public must wait longer for more vaccines to become available
BEST: Developer gets fast approval and has been concurrently manufacturing the vaccine during clinical trials. The vaccine is now ready to distribute in mass quantities
Here is how Russia’s Sechenov First Moscow State Medical University did its clinical trial:
- First group of 18 healthy volunteers got vaccinated on June 18
- The second group of 20 volunteers received the vaccine on June 23
- The volunteers were within the age group of 18 to 65
- They received a lyophilised vaccine or a powder from which a solution is prepared for intramuscular injection
- Some participants reported headaches and elevated body temperature, but resolved completely within 24 hours
- Participants have been kept in single or double wards on University campus
- They have to spend 28 days in isolation. After discharge, they will be monitored for 6 more months
- Psychological support is provided during isolation