Know about the Vaccine for Corona Virus

The first generation of COVID-19 vaccines is predicted to release approval as soon as the end of 2020 or early 2021. 

Multiple COVID-19 vaccines are currently in phase 3 trials with efficacy assessed as prevention of virologically confirmed disease. WHO recommends that successful vaccines should show disease risk reduction of a minimum of 50%, with 95% CI that true vaccine efficacy exceeds 30%. However, the impact of those COVID-19 vaccines on infection and thus transmission isn't being assessed. Albeit vaccines were ready to confer protection from disease, they could not reduce transmission similarly. Challenge studies in vaccinated primates showed reductions in pathology, symptoms, and viral load within the lower tract but did not elicit sterilizing immunity within the upper airways. Sterilizing immunity within the upper airways has been claimed for one vaccine, but the peer-reviewed publication of those data is awaited. There are reports of virologically confirmed SARS-CoV-2 re-infection of previously infected individuals, but the extent of such re-infection is unclear. Whether re-infection is related to secondary spread is unknown.

The immunological correlates of protection from SARS-CoV-2 infection and COVID-19 have yet to be elucidated. Pre-existing neutralizing antibodies appeared to have afforded protection against re-infection in people on board a fishing boat where there was an epidemic of SARS-CoV-2 with a high infection attack of rats.

By: Raghav Saxena

Birla School, Pilani