Introduction
infection
CORONAVIRUS, INFECTION
In December 2019, a cluster of a novel coronavirus, known as 2019-nCoV, cases were identified in Wuhan, ChinaThe immunity achieved through natural infection by SARS-CoV-2 has been shown to last for many monthsA SARS-CoV-2 recombinant spike (rS) protein nanoparticle vaccine adjuvanted with Matrix-M™ (NVX-CoV2373) was developed in USA. NVX-CoV2373 was assessed in a Phase 1/2It has become evident that the protection offered against COVID-19 wanes after a two-dose schedule of COVID-19 vaccinesIn India, the nation-wide primary COVID-19 immunization programme was started on 16 January 2021 with two vaccines: Covishield (ChAdOx1 nCoV-19, a viral vector vaccine) and Covaxin (BBV152, a whole virion inactivated vaccine)