It was on the eve of 2020 that China officially notified the World Health Organisation (WHO) of some cases of pneumonia with an unknown cause in Wuhan. The symptoms were common to several respiratory diseases, but occurrence of a cluster of cases within a short span of time, and with severity, raised the alarm.
Based on laboratory tests that ruled out the causative agent to be any known virus such as SARS, MERS or avian influenza, the world body on January 9, 2020 declared the causative agent to be a novel coronavirus. Within weeks, evidence emerged that the virus was capable of spreading from human to human, that it causes severe disease and has no known treatment. And within months, millions of cases were reported from dozens of countries. This turned 2020 into the year of the pandemic. The rapidity with which the global scientific community responded, it appears that 2021 could be the year of the vaccine.
The response of the scientific community to the pandemic was unprecedented. From characterisation of the novel coronavirus to a set of vaccines against it — everything was achieved in a span of less than a year. On January 10, 2020, a consortium of Chinese and Australian scientists released the first complete genetic sequence of the novel virus from a case of respiratory disease caused in the Wuhan outbreak. This triggered the interest of several scientific groups the world over, who started developing new
diagnostic tests, possible treatment and most importantly, vaccines against the virus. As the number of cases mounted in many countries, new insights were gained into the disease and several treatment options like hydroxychloroquine tried and protocols developed for management and care. All the information and knowledge produced was shared in real-time through journals and social media platforms of scientific research like bioRxiv and medRxiv.
Never before in the history of medicine, a vaccine against a new virus has been developed, tested, produced and administered in such a short time. The process of vaccine development, which took decades in the past, has been compressed and achieved within months. The corona vaccine is truly the breakthrough of 2020. Scientists started working on Covid-19 vaccines using traditional approaches (inactivated, virus-like particle) as well as new platforms (mRNA).
The level of hectic scientific activity can be gauged from the fact that WHO’s ‘Covid-19 candidate vaccine tracker’ is updated twice a week. On the last count, there were 60 vaccines in clinical development, undergoing various stages of human trial. Another 172 vaccine candidates are in pre-clinical stage. About a dozen Covid-19 vaccines are in various stages of development in India. A couple of vaccines have been licensed in the West and millions of doses have already been administered.
A number of factors are responsible for the time taken for a vaccine from bench to clinic getting reduced from several years to a few months. First, of course, is the fact that genetic information of the novel virus was shared as soon as it was available. Some groups already working on coronaviruses could tweak their efforts to work on the novel coronavirus. Others working on platforms like messenger RNA for several years also tested their platform for the novel coronavirus. All these developments got speeded up as funding agencies and governments provided the necessary funds, and placed purchase orders with manufacturers in advance. There was also great public-private partnership in vaccine development as seen in the Oxford University-Astra Zeneca and Bharat Biotech-ICMR projects.
Once developed in laboratory, vaccines have to be clinically tested for safety and efficacy, involving human volunteers. Normally, this entails three stages, one following the other. Regulatory authorities approved one stage of clinical trial based on results of the previous one. For example, the first stage human trial approval depends on the results of animal studies and first stage data forms the basis for approval of the second stage. It is a time consuming process, involving recruitment of trial participants, ethical approvals, enlisting hospitals for multi-centric trials, data reviews etc. National regulations also mandate that local clinical data is generated for vaccines developed in other countries to be marketed in own country.
Since the occurrence of recent pandemics like SARS and Ebola, the global health community has been discussing ways to fast-track vaccine development in the event of a pandemic. These ideas have now been implemented for Covid-19 vaccines. One of the significant ways to reduce ‘time to market’ is to allow phase 1 and 2 human studies in parallel, like it has been done for the Bharat Biotech vaccine. Regulators in many countries have also permitted local clinical trials of vaccines developed in China.
Vaccine manufacturers too have speeded up their processes. Even as clinical data is getting generated for regulatory approvals, they have gone ahead with mass manufacturing of vaccines.
This facilitates the availability of vaccine doses as soon as vaccines are licensed for mass use, as has happened with the Moderna vaccine in America and the UK. The Serum Institute of India and Bharat Biotech have kept vaccine doses ready for shipment in anticipation of emergency use approvals. The government, on its part, has conducted trial runs for the vaccine rollout. This way, the entire chain, from development to rollout, has been fast-tracked.
Vaccine manufacturers and the government will have to ensure that a mechanism is also in place for monitoring vaccine-related adverse events. This is critical as it is the first time a vaccine is going to be administered to the adult
population on such a large scale. Though vaccine hesitancy and the anti-vax movement are not major challenges in India, quick reporting and addressing of adverse effects can help prevent resistance to vaccination.
The Covid-19 vaccine development has provided a new template for future pandemics, and also for addressing other infectious diseases. If governments, international agencies, scientists and private companies can pool resources and expertise for Covid-19, they can surely do so for a plethora of other diseases that take a higher toll and are both preventable and treatable. That’s a hopeful note on which to begin the year 2021.