Covid-19 vaccines’ efficacy rates
Talking about the efficacy rate of over 90 per cent of Pfizer-BioNTech and Moderna vaccines, Dr. Kang said that it was encouraging to have two or maybe three vaccines based on the spike protection. Simplifying the impact of high efficacy rates, Dr. Kang said if randomisation ratio is 1:1, then half of the volunteers enrolled for clinical trials of a vaccine will get placebo and another half will be vaccinated. If 20,000 volunteers enrol for the clinical trial, 10,000 will get the vaccine and other 10,000 will receive a placebo. Out of 10,000 volunteers, if the infection rate is 10 per cent then there will 1,000 infected volunteers. If a vaccine has 50 per cent efficacy rate then 500 people will be infected and, if it has 90 per cent efficacy, only 100 people will be infected by the virus.
Dr. Kang has posed a few questions to vaccine makers who have released information regarding their Covid-19 vaccine candidates. These questions are — what will be the impact of vaccine in younger people, immunocompromised, pregnant women. She also sought to know the safety record, longevity of protection, nature of the immune response, and B-cell and T-cell components, as per the IE report.
Vaccination challenges before India
India needs an affordable vaccine that can be manufactured in large quantities and delivered hasslefree, Dr. Kang said. The ideal vaccine for India would be a single dose providing long-term protection. Oxford-AstraZeneca’s vaccine, branded as Covishield in India, would require USD10 per set of vaccination which will make the most expensive vaccination programme in India ever, Dr. Kang claimed. India does need a vaccine which cost under a dollar and the second wave Vaccine candidates must aim at producing vaccines which are less costly, Dr. Kang said.
Since the scale and magnitude of Covid-19 vaccination programme will be never-seen-before kind, the central government needs to start the communication process with groups that are likely to be vaccinated initially. The government needs to come up with a plan detailing the sequencing of the vaccination programme and how vaccination of priority groups will be done within states, Dr. Kang said. Dr. Kang pointed out that there should be more clarity on the delivery mechanism at the Centre as well as the state levels. She also asked whether these health workers will be from the government or private and is it feasible to vaccinate all health workers at the same time across the country.