Syllabus Section- Science and Technology
Why in news
The UK on Wednesday became the first country to approve the Pfizer/BioNTech vaccine against COVID-19, paving the way for mass vaccinations against the deadly novel coronavirus.
Significance
• When the first immunisation takes place of Pfizer's Covid-19 shot next week in the UK, it would mark the most rapid vaccine development for a pandemic in history following all the mandatory stages (the Russian and Chinese vaccines were approved before Phase III trials).
• From dosing the first trial participants on May 5 to getting approval for emergency-use authorisation in the UK in six months, the breakneck pace of developing the BNT162 vaccine by Pfizer and its partner BioNTech, which claims to offer up to 95 per cent protection against Covid-19, sums up the severity of the pandemic that has killed more than 1.46 million people and infected 62.8 million.
• Besides Pfizer, Moderna Inc, which was one of the first firms to start human clinical trials of its mRNA vaccine on March 16, has already applied for emergency use license in the US. Serum Institute of India, which is trialing a version of the AstraZeneca-Oxford vaccine, is also expected to follow suit within the next two weeks. Oxford University had begun Phase I trials of its ChAdOx1 nCoV-19 vaccine on April 23.
• The developments mark a remarkable turnaround since there was no antidote to the virus and the most optimistic prediction was a vaccine by the middle of 2021.
• According to the World Health Organisation (WHO), the average time to develop and make a vaccine publicly available until now has been 16 years.
• In fact, the vaccine that comes remotely close in matching the Covid-19 pace is the mumps vaccine, which took close to 4 years to get all necessary permissions and licensing. So far, only smallpox has been declared officially eradicated by vaccination.
How Covid-19 vaccines were developed so fast?
• What aided scientists in developing a Covid-19 vaccine in record time is the fact that it was not required to be made from scratch.
• Scientists had begun making vaccines for SARS and MERS, which belong to the coronavirus family, during their outbreaks in 2003 and 2012, respectively, only to abandon the efforts when the outbreaks petered out.
• Moreover, Pfizer and Moderna have used the novel mRNA technology for their vaccines which are faster to develop as they do not require companies to produce protein or weakened pathogens for the vaccine.
• The genetic material mRNA is easy to make in a laboratory and manufacturing an mRNA vaccine rather than a protein one can save months in time.
• Also, it must be noted that for most of the Covid-19 vaccines on the cusp of release or those already granted approval, the mandatory clinical trial process — designed to test whether the shots are safe and effective — was compressed into months in normally what takes approximately ten years. For example:
Phase I: In this step, the experimental vaccine is given to humans, usually between 20-80 subjects, to test its safety and dosage besides gauging whether it stimulates the immune system. While this process typically takes one to two years, for Covid-19 trials, it was done in about three months.
Phase II: In this stage, about several hundred individuals, split into groups age-wise such as children and elderly, are dosed in a randomized, double blind, placebo-controlled study. This process usually takes about three years but for Covid-19 vaccines, it was completed in 2-3 months.
Phase III: This is the most crucial stage, where the vaccine candidate is given to thousands of people, and can typically take two to four years. However, most of the drugmakers combined this with Phase II to expedite the process.
• Regulatory review: After Phase III trials, the vaccine developer submits a license application to the regulatory authority in their respective country, and final approval may take months or years. However, in emergency situations, like the Covid-19 pandemic, authorities grant emergency-use authorisation (EUA) in weeks.
Source- Indian Express