Written by N K Ganguly and Namita Jaggi
Historically, vaccines, not naturally acquired herd immunity, have eradicated infectious diseases like smallpox. They have been instrumental in checking diseases like polio. With the COVID-19 pandemic causing widespread morbidity and mortality, and with no effective, proven target drug available, there was a dire need to develop a vaccine at an unprecedented speed.
Cooperation and collaboration across global organisations, advancements in molecular biology and genomics, established modern vaccine platform technology, the innovative simultaneous conduct of different stages of the clinical trials, fast-track authorisation and adequate funding from global organisations accelerated vaccine development. Seven vaccines have received emergency authorisation in different parts of the world in less than a year since WHO designated SARS-CoV-2 a pandemic.
Different technologies have been used to develop the vaccines worldwide, all leading to the production of the SARS-CoV-2 spike protein and protective antibodies against it. The nucleic acid vaccines — mRNA (Pfizer/ BioNTech and Moderna) and the DNA (Zydus Cadila) — have been used for the first time. These vaccines bear the genetic blueprint which when sent into the body creates codes for the spike proteins and tutors the body to produce protective antibodies. Viral vector vaccines achieve the same goal by utilizing harmless vectors (tested for safety) for example, the chimpanzee adenovirus in the Oxford Astrazeneca vaccine (Covishield) and human adenovirus in the Sputnik 5 and the Johnson and Johnson vaccine with the genetic instructions for SARS-CoV-2 spike protein stitched onto the virus vector genome.
The technology used by Novavax does not contain the whole virus or nucleic acid but a virus-like particle (VLP) virus to activate the immune response. Conventional methods using the whole virus in an inactivated or killed form have been used by the indigenous Indian vaccine manufacturer Bharat Biotech in collaboration with the ICMR (Covaxin).
Globally, 20 vaccines are in the phase III clinical trials. Nine vaccines are being developed in India; two of them, Covishield and Covaxin, have received emergency-use authorisation.
Since the first case of COVID-19 on January 31, 2020 in India, the government has been delivering timely and effective guidelines, upgrading infrastructure in hospitals and testing labs, building up capacity in personnel, and ensuring adequate supply of personal protective equipment and other essential supplies. On January 16, it embarked on the mammoth task of rolling out one of the largest vaccination programmes of the world based on the electoral system under the guidance of the national expert group on vaccine administration in COVID -19 (NEGVAC). Logistical requirements — transporting the vaccines from the Indira Gandhi International airport to regional storage centres at Chennai, Mumbai, Kolkata and Karnal and further to over 3,000 vaccination centers with trained vaccinators and a well-organised delivery system, maintaining the cold chain – seem well catered to. Two digital systems, the COVID Vaccine Intelligence Network (Co-WIN) and an electronic Vaccine Intelligence Network(eVIN) have been created to integrate vaccine supply to 34 states/Union territories, 720 districts and 2,8500 cold chain points. Drills on advocacy, training of vaccination staff, media engagement, social mobilisation and community engagement have been undertaken at the national, state, district and subdistrict level.
However, there are many challenges looming ahead. To develop herd immunity, 60-70 per cent of the Indian population needs to be vaccinated (approximately 600 million people). At the current rate of 3 lakh people being vaccinated per day (100 each at the 3006 session sites), we would be only able to vaccinate 109 million (8 per cent) of the Indian population in a year (assuming that vaccination were to happen every day of the week as opposed to 4 days a week as of now) and the inoculation drive would take eight years. To circumvent this, we would have to give 25 lakh doses per day, by either increasing vaccination sites or number of beneficiaries to 850 per site. Opening up the vaccines to the market and the private sector could also be an answer where vaccine availability would increase exponentially as also ease the availability of phase-4 data.
There seems to be vaccine hesitancy, even amongst aware healthcare workers. Such hesitancy will have to be addressed adequately in the community at large. Transparency in data, generating Phase IV clinical trial data, evaluation by an independent third party and the conduction of clinical trials in global settings with various ethnicities under stringent regulatory processes would reassure the population.
Priority vaccination list should be expanded to populations working in mass campaigns, the elderly, teachers interacting with a large population, individuals involved in public roles, and eventually moving towards opening vaccination to everyone who is eligible.
Confidentiality of health data uploaded on sites would be a challenge and all steps to avoid misuse should be taken. Reaching the vaccine to the poorest of the poor in remote locations could be supported by subsidies. To make available 1.8 billion doses for 70 per cent of our population we would have to ramp up the country’s manufacturing capacity.
Finally, this is the time to encourage other adult vaccinations, keep our focus on other pressing health issues and build up our economy. There should be no complacency with respect to preventive measures pertaining to hygiene, social distancing, masking and keeping surfaces that are frequently used clean. Now is not the time to let our guard down or indulge in COVID-risky behaviour.
Ganguly is the former director-general ICMR; and Jaggi is the chairperson, labs and infection control, chief education and research at Artemis Hospital Gurgaon