Many Covid-19 vaccine candidates have reached phase 3 clinical trials, and the world is hopeful that one or more candidates will clear the regulatory demands and be authorised for commercial deployment in the near future.
While the wait remains, India must look ahead and start deploying strategies for prioritisation and distribution of the vaccine once it becomes ready. Although it would be ideal to immunise every individual as soon as the vaccine is approved, practically it won’t be feasible.
The production capacity will be the rate-limiting step and hence, initial supplies will be limited. Additionally, the logistics of distribution and administrative capacity of vaccines in a large country like ours could potentially cause delays in making the vaccine available to everyone.
So, it may take many months until everyone is immunised.
In such a case, a plan is essential to prioritise the groups who need to be vaccinated urgently and groups who can wait until supplies increase.
Who should wait
Clinical trials usually take an average of six to seven years. Even then, no vaccine is 100 per cent effective. However, the pandemic has expedited the speed at which the clinical trials are run and a potential vaccine could be made available within a year.
Considering that the vaccine is approved following the highest safety standards, its effectiveness is still uncertain. Due to weak immune responses in older adults, they would still require a higher dose of the vaccine for it to be effective. Hence, it is best to avoid vaccinating older adults in the first phase until more information is made available.
The current clinical trials are based on healthy adult volunteers (18-55 years) with no comorbidities. As limited evidence will be available from the trials for the safety and efficacy of the vaccine for individuals with co-morbidities (eg, diabetes, cardiovascular disease, chronic kidney disease, etc), rare diseases, and children, they may need protection from infection through indirect means. Also, with the data available so far, children are half as susceptible to SARS-CoV-2 as adults. Therefore, they can be protected from infection by immunising their contacts.
Economic and social wellbeing is the need of the hour. In response to the pandemic, lockdowns were imposed to curb the spread of the virus. This led to the closure of many businesses and, as a result, reduced economic activity, increase in unemployment and food and housing insecurity. Societal interactions have also been disrupted. Thus, along with public health, the focus of any vaccination strategy should take into account economic and social wellbeing.
3-phase vaccination strategy
A pragmatic approach would be to identify living and working conditions that have demonstrated an increased risk of exposure to Covid-19 infection.
In the initial phase, the vaccination should be provided to healthcare workers who are in contact with Covid-19 patients, such as healthcare workers and emergency medical services personnel.
Although they use personal protective equipment (PPE), they aren’t completely protected and are still at a high risk of infection. Prioritising frontline healthcare workers also protects the healthcare system.
Workers who are deputed for the vaccination campaign — vaccinators and supply chain workers — should be next in line as they will be exposed to thousands of people who could be Covid carriers. Similarly, other essential workers in sectors like transportation, food system, warehouse, and delivery who are at a higher risk of infection, should be prioritised. This is critical as it protects essential services and enables ramping up economic activity.
Phase 2 of the vaccination strategy could focus on protecting other essential service personnel who are needed to maintain public safety and health. Personnel involved in emergency services, public health, police, healthcare support staff, maintenance services, and workers operating electricity, water, sanitation, financial and fuel infrastructure need to be vaccinated.
To enable more economic activity to resume, other essential and non-essential workers who cannot work remotely and have higher infection risk in their workplace, such as retail and industry workers, need to be immunised.
The groups that can be immunised during phase 3 of the strategy are those involved in educational sectors, household contacts of persons with co-morbidities, farmworkers, others who cannot work remotely. The final phase can then vaccinate everyone else.
States will play a crucial role, transparency a must
While all groups should be offered a vaccine concurrently, it is only possible if enough of the vaccine is available at the beginning. Since this scenario is unlikely, hard choices must be made.
Once more than one vaccine candidate is available in the public domain, more people can be immunised at the same time.
It is expected that the prioritisation and distribution plan might be formulated centrally, however, much of the implementation will be done by the state and locally.
Therefore, states should further plan to ensure vaccination is distributed and administered to the targeted groups, especially those that may be hard to reach. Finally, any allocations should be made transparent to the public alongside the reasoning to prevent any social tensions and confusions.
(Manjeera Gowravaram has a Ph.D. in RNA Biochemistry from Freie Universität Berlin and is a participant in Takshashila Institution’s GCPP (HLS) programme.)