With Bharat Biotech announcing 81 per cent interm efficacy for India's first indigeneously developed coronavirus vaccine Covaxin, India has joined the league of front runners across the globe who have developed the most efficient vaccines for this pandemic.
So far, the Pfizer-BioNTtech and Moderna vaccines, made through a novel platform technology never used in humans before, are proven to have maximum efficacy. The Pfizer vaccine showed efficacy of 95 per cent at preventing symptomatic COVID infection after two doses and the Moderna vaccine is 94.1 per cent effective after the second dose. However, this vaccine's efficacy was seen slightly lower in people above 65 years. These vaccines are made using messenger RNA, or mRNA, technology to deliver virus's genetic code to cells. India's soon to be launched Zydus Cadila vaccine also uses the same technology.
Among the viral vaccines, a traditional way of vaccine development with dead or live virus, Russia's Gamaleya's Sputnik V vaccine claims to have the maximum 92 per cent efficacy. Sputnik V interim analysis of the phase 3 trial data showed 91.6 per cent efficacy against COVID-19 and was well tolerated in large studies, Gamaleya had claimed and data was published in reputed science journals.
The efficacy of AstraZeneca-Oxford University developed Covishield vaccine, manufactured by India's Serum Institute of India, is shown to have a satisfactory efficacy of about 62 per cent in different data that has come out so far.
On February 27, the Food and Drug Administration issued an emergency use authorisation for one-dose vaccine by Johnson & Johnson's unit Janssen. Its efficacy ranges from 66 per cent to 85 per cent. It showed 72 per cent protection in studies in the United States, 66 per cent in South America and 57 per cent in South Africa.
So far four Chinese vaccines have hit the markets, but complete trial data is yet to come out. Beijing-based biopharmaceutical company Sinovac's CoronaVac vaccine's data on the first and second phase trials were published in the Lancet, a reputed scientific journal. Interim data from late-stage trials in Turkey and Indonesia said the vaccine was 91.25 per cent and 65.3 per cent effective respectively. First studies in Brazil said it was 78 per cent effective, but in January, this was revised to 50.4 per cent.
Sinopharm, a Chinese state-owned company's vaccine is claimed to have 79 per cent efficacy. This vaccine is used in large-scale in vaccinating the UAE population, along with Pfizer vaccine, and the vaccine was 86 per cent effective, according to interim results of its phase three trials. The other two Chinese vaccines were launched only a few days ago.