The efficacy rate determines the workability of a given COVID-19 vaccine under clinical settings and showcases how potent it could be, once approved. Now, all four vaccines that we have passed the WHO nod for approval, which state that a vaccine should be at least 50% efficacious against transmission.
However, from what has been seen, clinical trials and real-time usage have suggested that all the vaccines, while effective against the SARS-COV-2 strain, have different efficacy rates. The higher the efficacy rate may promise a coronavirus vaccine more favorability and usage as well. In the current scenario we have, the four vaccines offer different efficacy rates.
Covishield vaccine, which was the first to be approved for use in India has a proven efficacy rate of 70%, which can be scaled up to 91% when both doses are administered 8-12 weeks apart. The vaccine also mounts a higher antibody response and prevents severe outcomes. Covaxin, which recently completed the third stage of trials shows an efficacy rate of 78%, additionally providing 100% protection against severity and mortality.
The third COVID-19 vaccine that we have, Sputnik V, according to the RDIF demonstrates an efficacy rate of 78.6% to 83.7%, as per trials and case studies conducted.
Of all, Moderna’s hopeful COVID-19 shot, mRNA-1273, has been found to be the most efficacious of all. While the company wrapped up trials in December, it has been found that the vaccine has an efficacy rate of over 91%, with immunity peaking after administering two doses.