The Participants We Need in Phase 3 Trials

Context: Two COVID-19 vaccines have been accepted for Phase 3 trials after passing the Phase 1 and Phase 2 trials. Health care workers and vulnerable subjects shall be given priority to join COVID-19 Phase 3 trials.

Reasons for Likelihood of protection from Vaccine-induced immunity

• Provides Natural Infection: which induces both a virus­neutralising antibody and T­ cell­mediated immunity.

• When a vaccine candidate produces similar immune responses, the probability of it being protective against the disease is high.
• The vaccines, thus passed Phase-2 should, therefore be assumed to be protective.

• Demonstration of Immunogenicity: Interim reports on Phase 1 and Phase 2 vaccine trials from China, have demonstrated immunogenicity and short­term safety.

Argument in Favour of Prioritising Vulnerable and Healthcare Workers in Vaccine Trials:

• Following the 3-fold objective of vaccination: which prioritises the vulnerable and occupationally exposed individuals apart from eventually eradicating the viral infection.

• A case for Vulnerable Sections:

• Higher mortality rate: Vulnerable groups such as the elderly and those with co-morbidities have five-fold to 15-fold greater mortality when they get COVID-19 than others.
• To make the trials Inclusive: To facilitate prioritised vaccination of those who did not have an opportunity to enrol as volunteers for the trial.

• Under normal circumstances, only health adult volunteers are inducted neglecting the efficacy of vaccine on vulnerable subjects.

• Immunising the subgroups straight away after the trials:  Trials in these groups can help to immunise them when the vaccine is finally launched. 

• A case for Healthcare Workers: 

• Historical Experience: often been the first to volunteer to participate in several physiological and pharmacological studies of an experimental nature.

• High-risk work environments: They have a high risk of repeated exposure to infection. 

• Encourages Public: Participation of healthcare workers will motivate and enthuse members of the general public to participate in the trial and make recruitment easier.

• Morale booster: Inclusion of healthcare workers in the Phase 3 vaccine trial may prove to be the silver lining and boost the sagging morale of healthcare workers.

• Loss of colleagues, of increasing numbers of infected healthcare workers, the struggle to cope with the escalating number of cases, and the worries about risk to their immediate family have eroded the morale of all healthcare workers in India. 

• A better understanding of the Vaccination: 

• Would be better able to provide informed consent.
• They can clearly distinguish between placebo and real effect.

• They can provide with information about side effects and can self-report adverse events with relevant details can be obtained.

Way Forward:

• Replicate HERO (Healthcare Worker Exposure Response and Outcomes): a framework designed by Duke Research Institute to encourage healthcare workers to participate in all COVID-19 clinical trials.

• Indian Medical Association and nursing and paramedical professional organisations should come together on a similar platform.

• Risk-based categorisation: 

• Those healthcare workers who have already contracted COVID­19 and who do not need the vaccine will be listed in the National Registry.
• Of those who have so far not been infected, IgG antibody testing will identify antibody-positive subjects who do not need vaccination. – constituting 30-40% as is the case in metros.
• The remaining ones should be allowed on a priority basis.

Conclusion: All around it would be a good idea for healthcare workers and vulnerable subjects to enrol in the COVID-19 vaccine Phase 3 trials in India.