The Big Billion Indian COVID 19 Vaccine Challenge

Abstract

Come 2021, COVID-19 vaccination is expected to be one of the most eagerly awaited events in the timelines of every nation world-wide and India is no exception to this mammoth global initiative. It is heartening to note the highly promising efficacy data from at least six vaccine makers i.e., PfizerBiontech, Moderna, Oxford-AstraZeneca, Gamaleya Center’s Sputnik V vaccine, Novamax and the Johnson and Johnson vaccine. While the Pfizer-Biontech vaccine has claimed an efficacy of 95 %, the Moderna in its latest release has claimed an efficacy of 94%. The adenovirus-based vaccine developed by OxfordAstraZeneca has claimed an 70% average efficacy, while the Russian Gamaleya Center’s Sputnik V vaccine, another adenovirus-based vaccine, has reported an efficacy of 91%. These results are expected to be formally published in peer reviewed journals soon. Further, many vaccine candidates are being developed at an accelerated pace and more than 180 such candidates have in fact reached the phase of clinical evaluation. It is commendable to note that barely a year since the emergence of the COVID19 pandemic, multiple vaccine developers have defied the traditional timelines of many years for vaccine development and are now poised to secure emergency use authorization [1]. The front runner vaccine candidates for India’s COVID-19 response seems to be the vaccines developed by OxfordAstraZeneca and the Bharath Biotech thus far. Although Pfizer India has formally approached the Drugs Controller General of India (DCGI) for EUA of its Covid-19 vaccine, there seems to be no clear roadmap for the availability of the mRNA vaccines developed by Pfizer as well as the Moderna in India till date. It must be noted that the specialized cold storage requirements for the above mRNA vaccines may be a deterrent to its large-scale use in India. This is a rapidly evolving field and clinical recommendations and policy decisions are expected to periodically change with the accumulation of more and more scientific evidences. From the immunological stand-point there seems to be a lack of clarity as to what condition induces a stronger immune response i.e., a natural COVID-19 infection or following vaccine administration. Studies have reported a huge dynamic variation in immune responses to natural infected patients. The diversity in the immune responses to the natural infection can be partly explained by the differences in the amount of virus to which the contact was exposed to, among other factors. Experts are of the view that Covid-19 vaccination can predictably prevent illness and it undoubtedly seems to be a much safer bet. Hoping to get and subsequently recover from a Covid-19 infection clearly seems to be a far more dangerous option considering the unpredictable responses, severity of infection and the outcomes of a naturally acquired COVID19 infection. Further, nearly a third of the patients (including even younger patients with no comorbid conditions) who recover from COVID-19 infection seem to have chronic symptoms like exhaustion, tachycardia, symptoms similar to lupus or rheumatoid arthritis and even erectile dysfunction. The safety data of the various COVID-19 vaccines administered to many thousands of patients seem to suggest a favorable safety profile thus far with minimal serious side effects [1]. Preliminary reports further suggest that COVID-19 vaccination can augment the immune responses in patients who have recovered from a natural COVID-19 infection. It is important for the treating clinician to understand that the ongoing vaccine trials only test for the efficacy of the candidate vaccines, * Arvind Krishnamurthy [email protected]