The battle of COVID-19 vaccines: Which one is the ideal from Indian perspective?

 

As rightly put by the finance minister Nirmala Sitharaman in her budget speech: COVID-19 pandemic “is the dawn of a new era, one in which India is poised to be a land of new hope”; the entire world is eyeing India as a front runner to eradicate the dreadful virus. The situation demands that India exponentially manufactures sufficient vaccines.

The country now has dual challenge: vaccinating its own people in a time-efficient way on one hand and supplying enough vaccines to the rest of the world on the other hand. In order to meet both the need, expanding collaborations at the interface of vaccine production and simultaneous manufacturing of multiple vaccines have become imperative. With India currently having two approved vaccines available; let’s take a deep dive and see what other options might commensurate to Indian context in near future.

Efficacy is by far the most important factor while selecting a vaccine. Currently Bharat Biotech vaccine “Covaxin” and Oxford-AstraZeneca vaccine “Covishield” have shown >90% protection against COVID-19 and also demonstrated partial protection against at least one of the newer COVID-19 variants. Two other vaccines respectively from Pfizer and Moderna, which are already clinically approved and currently being administered in UK and USA along with several other nations, have shown remarkable success thus far. It may be noted that results of the phase III clinical trials confirm and endorse the actual efficacy of any vaccine. There are currently 20 more vaccine candidates worldwide that already entered in phase III clinical trial and many of them if not all, hopefully will be approved anytime soon. These include but not limited to the candidates from Novavax, Janssen, Inovio, Gamaleya, Moderna and Pfizer. Interestingly among all these candidates, Sputnik V from Gamaleya has shown remarkable results as published in top tier international medical journal “Lancet”. One key success of this vaccine is that it is almost equally protective even in the recipients of >60 years old. However, the efficacy of this promising vaccine is yet to be tested and proven against COVID-19 mutants like South African, Brazilian or UK strains.

Although Pfizer previously pursued its request for India to approve its COVID-19 vaccine, the US-based pharma giant withdrew the application for emergency use of its COVID-19 vaccine in India. However, it is also reported that the company will continue to engage with the government authority and re-submit its approval request with necessary additional information. Meanwhile, TATA Group’s newly launched medical venture “Tata Medical & Diagnostics” showed interest in Moderna’s vaccine and considering necessary clinical trials in association with the Council of Scientific & Industrial Research (CSIR).

Safety and immunogenicity are the factors, the Indian government should carefully look at while making a choice. One of the safety parameters remains post vaccination lower rate of severe adverse events (SAEs). According to the reports of Independent Data Monitoring Committee (IDMC) for SAEs of current or prospective vaccines as discussed thus far, Gamaleya stands at 0.27%, Pfizer at 0.58%, AstraZeneca at 0.66% and Moderna at 0.97%. Among several other factors, immunogenicity and efficacy of a given vaccine also depend on host genetic factors. In addition to this, genetic predisposition to COVID-19 is not yet known. On this note, although Pfizer and Moderna’s vaccines are ~95% effective, participants of clinical trials were largely confined to white population while Asians remained at paltry