The fact that only one in 10 healthcare workers returned for the second dose of the COVID-19 vaccine as of February 15 indicates that they have probably understood the advantages of delaying it for 12 weeks — that the 12-week interval between the two doses affords considerably better protective efficacy than the four-week interval currently followed in India.
Only about half of those offered the first dose actually took it, pointing to widespread vaccine hesitancy even among healthcare workers, the best-informed segment of society. After all, they should have been the most willing recipients of the vaccines given that they are at highest risk of contracting infection due to repeated occupational exposure. Unfortunately, clear and correct scientific information — on vaccine efficacy and the potential side effects — was not provided before the two vaccines were rolled out.
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Over and above the Phase 3 clinical trial results on COVID-19 vaccines that are currently used in different countries, is there any other evidence to say that vaccination programmes are effective?
Peak and the rate of decline
A study of the epidemic curves of different countries in different phases of their epidemics gives us insights into vaccine effectiveness regardless of which vaccine is used. The peak of the COVID-19 global pandemic, a statistical derivation, occurred in the second week of January 2021, followed by a steep decline in the number of new cases reported worldwide, with a halving time of 35 days. The death rates peaked on January 29, after a lag time of 18 days after the pandemic peak, reflecting the time lag between infection and death, corroborating the conclusion that the global pandemic peak is well and truly behind us.
Individual countries that embarked on mass vaccination prior to or around the time of their respective epidemic peaks show a faster rate of decline with shorter halving times of 17 days (U.K.) and 29 days (U.S.). India began rolling out its vaccines on January 16, long after the peak was over on September 16, 2020, and close to the time our epidemic was transitioning into the endemic phase. India’s halving time in the number of new infections was about 42 days, as the vaccine roll-out was too late to accelerate the speed of epidemic decline. As India seems to have entered or is about to enter the endemic phase by March 2021, we have to presume that the predicted herd immunity threshold of 60% infection of the entire population is about to be reached.
Also read | ‘COVID-19 herd immunity unlikely in 2021 despite vaccines’
Time for targeted vaccination
Countries like India that missed the opportunity to authorise emergency use of the vaccines earlier during the epidemic in order to blunt it, and are now nearing the endemic phase, will be well advised to implement targeted vaccination to prevent deaths and eradicate the infection. Mass roll-out is not necessary now.
State-wise utilisation of the allotted vaccines shows varying vaccine acceptance by healthcare workers offered the vaccines on a priority basis. Vaccine hesitancy is due to poor understanding of the benefits and risks of vaccination, perhaps with an exaggerated perception of the vaccine’s side effects due to media reports. This could be rapidly dealt with by a decentralised process of information-education-communication by the public health authorities at the level of each district, town and panchayat. All media, print and electronic, would do well to present accurate facts and health departments in each State should publish the side effects of the vaccines in detail to dispel mis-trust. This needs to be done on a war footing.
Comment | The time for — not mass but targeted vaccination
Utilising funds
The Central and State governments have set up vaccination centres at great expense, with a liberal budgetary allocation of ₹35,000 crore. It is important that the allotted funds are properly and fully utilised by running the vaccination centres to full capacity. However, ground-level data show poor utilisation of this valuable resource. Even States such as Tamil Nadu and Kerala, which have an excellent record of health management, are utilising only about 30%-40% of their planned capacity. This in turn, leads to considerable waste of time, funds and human resources.
The Health Minister has announced that India will begin to enrol, register and start vaccinating the elderly and vulnerable (those with co-morbidities) from March 1. This will fill all the empty slots in vaccination centres. This will help us prevent hospitalisation for severe COVID-19 cases and prevent deaths due to severe COVID-19 faster.
Comment | Improving Covishield efficiency
Apart from this, accepting scientific information on the advantages of delaying the second dose of the Covishield vaccine to 12 weeks will further increase the number of available slots for the elderly and vulnerable to access early vaccination and be better protected. This requires an immediate policy decision by the Ministry of Health and Family Welfare. This approach will not only yield rapid results but will set a model for other middle- and low-income countries to emulate. Vaccine hesitancy on the part of the people of India and policy hesitancy on the part of the government will seriously hamper achievement of the twin targets of preventing COVID-19 deaths and eventually eradicating COVID-19, goals we strongly advocate.
Dr. M.S. Seshadri is Medical Director, Consultant Physician and Endocrinologist, Thirumalai Mission Hospital, Ranipet, Vellore; and Dr. T. Jacob John is retired Professor of Clinical Virology, Christian Medical College Hospital, Vellore
