Refine the Covid-19 vaccination strategy

Research has shown that the pandemic has disproportionately affected regions with a high per capita income and a high burden of NCDS

Delhi had its first Covid-19 case this week, last year. Over this period, India has been able to keep the number of new cases, transmission rates and deaths at relatively lower levels, compared to many developed nations with better public health systems. Till recently, we have also seen a dip in infection rates in many parts of the country.

Having said that, the pandemic is not over until it is over. In fact, we need to be extra cautious during the downward trend of number of new cases. Pandemics also behave in set patterns in terms of trajectory. I wrote last June that Covid-19 is no exception and there will be multiple peaks, and that we need to prepare the health care system for surges. Even as the brutal first wave of the pandemic waned, the numbers have begun rising again. With the opening of borders and international travel, it is, also, almost impossible to stop newer variants from entering India.

As we enter into the second year of the pandemic, we do have reasons to be optimistic. The momentous scientific achievements of the past 12 months have been the development, testing, scrutiny, and approval of vaccines in the shortest possible timeline. Vaccination is the single-most important strategy to end Covid-19. Despite the appearance of multiple Sars-cov-2 variants as well as general vaccine hesitancy, vaccines provide hope. The benefits of vaccination far outweigh the rare but possible risks as per our present understanding.

Though there has been steady progress in the world’s largest vaccination campaign in India, which began in mid-january, there is still a long way to go before it achieves targets. Since the vaccination roll-out drive began at a time of falling infection rates, it gave us a crucial window to get the better of the virus quickly. The experience from the West shows that the second, or subsequent, waves are usually more pronounced.

The second phase of the roll-out, which began this week, is a commendable step towards expanding the reach of the vaccine as well as making it available at affordable rates in the private sector. The rationale behind who we vaccinate, and in which order, is crucial to achieving the goal of vaccinating the maximum number of people at risk and towards achieving vaccine-induced herd immunity. Since there is no lack of intent, effort, or resources, an alternative approach should be explored, which may turn out to be complementary to the existing strategy.

One of these is vaccine deployment based on the burden and severity of Covid-19 in different states. There have been major state-level differences in the burden and mortality from Covid-19 owing to the large size and the heterogeneous population of the country. As some of us reported in Macrolevel association of COVID-19 with non-communicable disease risk factors in India (published in Diabetes & Metabolic Syndrome: Clinical Research & Reviews), the more urbanised states have a greater higher proportionate case burden and mortality from Covid-19 than rural ones. Greater Covid-19-related mortality has also been reported among persons with various noncommunicable diseases (NCDS). Our paper was based on an analysis of cumulative and weekly national and state-level data on cases and deaths from a publicly available data. This was correlated with health care-related factors and social variables.

The study covered at least 9.5 million Covid-19 cases and 135,000 deaths reported in India from March 2 till the end of November 2020. While the national burden of cases and deaths is 6900/million and 100.4/million, respectively, there were wide disparities in rates of cases and deaths across states, with reported cases of more than 20,000/million in states of Delhi and Goa and 10,000-20,000/million in a number of states. Similarly, deaths rates of more than 300/million are observed in Delhi (490), Goa (434) and Maharashtra (383). The case-fatality rate also showed significant differences, with less than 0.5% in Mizoram, Arunachal Pradesh, Kerala and Assam to more than 2% in Punjab, Maharashtra and Sikkim.

Data on various state-level demographic indices also showed wide variability. There was significant positive correlation of state-level Covid-19 cases and deaths per million, respectively, with epidemiological transition index (0.59, 0.44), literacy (0.46, 0.46), indices of health care availability (0.23, 0.18), health care accessibility and quality (0.71, 0.61), urbanisation (0.75, 0.73) and human development (0.61, 0.56). These figures reveal that just as our population is ageing and the disease profile is changing from infectious diseases to lifestyle ones (which is the essence of the epidemiological transition index), the pandemic is also showing a similar trend with states with a high per capita income, and a high burden of these NCDS, displaying a high burden of Covid-19.

Our analysis shows that in India, the more urbanised and better-developed states have a greater burden and mortality from Covid-19 and need vaccinations earlier than other states. This study also reaffirms that the pandemic in India is still an urban phenomenon. In countries with a similar profile — a larger proportion of rural population — including China, Brazil, Iran, Mexico and South Africa, reports have highlighted a similar predominantly urban nature of the disease. This has important implications for the implementation of population- and individual-level preventive measures and equitable vaccine deployment.

A judicious strategy targeted at the urban population, especially the vulnerable, could be the most appropriate intervention. My suggestion is that states such as Kerala, Delhi, Maharashtra and Tamil Nadu should get priority in the vaccination drive. This re-prioritisation of vaccine deployment may well be an alternative way out of the pandemic and help us return to a semblance of normalcy across the country soon.

Rajinder K Dhamija is head, neurology department, Lady Hardinge Medical College and SSK Hospital, New Delhi The views expressed are personal