Table of Contents
VACCINE
- According to the World Health Organization’s latest count, 13 experimental vaccines are being tested in humans and more than 120 others are in earlier stages of development even as the infections near nine million, including 468,484 deaths.
WHEN?
- The ones developed by Moderna Inc, China’s Sinovac Biotech and UK’s Oxford-AstraZeneca — are set to enter late-stage trials.
- If all goes well, we may have a vaccine for emergency use by November even though experts have said getting regulatory approval followed by mass production and supply chain issues may push the development into next year.
LEADING ORGANIZATIONS
The World Health Organisation’s (WHO) Solidarity Trial, the UK’s RECOVERY Trial and the US’s ‘Operation Warp Speed’ are three of the leading scientific efforts pivoting research in the battle against Covid-19.
STAGES
- Firstly, a new vaccine candidate has to pass testing in animals, following which clinical trials kick in. Then, over three phases, the vaccine candidate’s safety and efficacy are tested as per protocols. A fourth stage involves collection and analysis of post-marketing data.
- Phase I trials: This is the first step where the experimental vaccine is given to humans, usually between 20-80 subjects, to test safety and dosage and check whether it stimulates the immune system.
STAGES
- Phase II trials: In this stage, a larger group of several hundred individuals are enrolled for testing and they are split into groups age-wise such as children and elderly. The Phase II testing studies the candidate vaccine’s safety, immunogenicity, proposed doses, schedule of immunisations and method of delivery.
- Phase III trials: Since certain side effects may not surface in the smaller groups of humans tested in earlier phases, the vaccine candidate is given to thousands of people in this stage. Here, the scientists check how many become infected compared with volunteers who receive a placebo. These trials can determine if the vaccine protects against the coronavirus.
STAGES
- Approval: After Phase III trials, the vaccine developer submits a license application to the regulatory authority in their respective country. The regulator then inspects the factory where the vaccine will be made and approves its labeling.
- During a pandemic, a vaccine may receive emergency use authorisation before a formal green signal.
TYPES OF VACCINES
- Genetic vaccines: These are the vaccines that use the genes of the coronavirus (in the form of DNA or RNA) to provoke an immune response.
- Viral vector vaccines: These vaccines use a virus to deliver coronavirus genes into cells and provoke an immune response. These viruses are weakened so they cannot cause disease.
- Protein-based vaccines: These vaccines use a coronavirus protein or a protein fragment to provoke an immune response by mimicking the coronavirus’ outer coat.
- Whole-virus vaccines: Such vaccines use a weakened or inactivated version of the virus. These vaccines are created by inactivating a pathogen, typically using heat or chemicals. This destroys the pathogen’s infectivity while retaining immunogenicity
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