Covid-19: Strengthen frontiers of response
Smart and equitable testing and establishing a pathogen genome surveillance network are important to shape the trajectory of the virus
With India witnessing an increase in the number of Covid-19 infections, the need for an effective response has once again come to the fore. Since the beginning, the messaging for tackling the pandemic from global institutions, the scientific community, and national governments has been persistent and ubiquitous — test, test, test.
A year later, testing has become central again to combat the second wave and contain the spread. This time, however, variants of concern (VOC) have opened up new frontiers exposing the country to unanticipated risks. The reproduction number of the virus (R0) is also rising exponentially, either as a coincidence or a consequence of VOC. While India progresses in its vaccination campaign, more evidence is awaited to conclusively determine the effectiveness of current vaccine candidates against existing and emerging VOC. As such, it is prudent to rethink the response strategy with recalibrated and smart tools.
India’s testing journey is a remarkable case study in itself — from heavy reliance on imports for test kits to eventually driving exports globally through indigenous manufacturing. Through unprecedented scientific collaborations, India was able to isolate the original virus strain early and expedite the development of indigenous antibody testing kits and vaccines.
Now it is time to move beyond diagnostic security and bring in considerations of equity, cost-effectiveness, and scalability in testing. As it stands, the testing continuum has the potential to be further refined to cater to diverse populations, especially underserved communities residing in low-resource settings. Testing can be optimised through an assortment of tests with clear guidance on their suitability to different contexts, and by establishing mass-testing platforms. A pooled procurement mechanism for the gold standard RT-PCR kits can trim costs and bring down the price, as per a modelling exercise for improving the cost-efficiency of Covid-19 testing undertaken by the Indian School of Business (ISB). Attuning the response strategy to address diverse and evolving needs is integral to entrench equity and accessibility while scaling up the quantum of testing.
So far, India’s Sars-cov-2 genome sequencing efforts point to the circulation of variants of the United Kingdom (UK) (B.1.1.7), South African (B.1.351), Brazilian (P.1) lineage, as well as a new double and triple mutant (B.1.617 and B.1.618) variant among the population. To date, India has sequenced less than 1% of the total positive samples (15,133 as of April 23, 2021), compared to 8% in the UK and 4% in the United States.
Moreover, it is not linked with surveillance, epidemiology, and public health. More efficient mutants with greater transmissibility, which in all likelihood will continue to emerge, pose a looming risk to an already overstretched health system and the extensive vaccination programme.
In the face of these evolving dynamics, the testing continuum needs to incorporate robust pathogen genome surveillance systems as well. In this present moment of urgency, the focus should be targeting genome sample collection from viral cesspools — sewage systems, wet markets, clinical settings, and outbreak sites. Analysis of virus sequences is also instrumental in measuring the outcome of diverse strains. Moreover, integrating pathogen genome surveillance data with available clinical, epidemiological, and serological datasets offers realtime intelligence on current and future outbreaks.
Fortunately, superior pathogen genomic capabilities have even more profound benefits; they serve as a critical pillar for long-term health needs. The Indian Sars-cov-2 Consortium on Genomics (INSACOG) has already demonstrated that a coordinated and organised approach adds tremendous value to pathogen-sequencing and data-sharing. Along the same lines, the institutionalisation of such a framework for sustained collection, analysis and application of pathogen genome intelligence can secure preparedness against other high burden diseases and future health threats.
Although India has administered at least one shot to more than 122.8 million people as of Tuesday night, this is 13% of all adults in the country who will be eligible for the shot from May 1 (there are 940 million adults in the country), the vaccination programme may still take a few months to inoculate a critical mass of its massive population.
Approval of vaccines already cleared for use in foreign countries will provide some relief. However, export restrictions and production shortages pose limitations worth consideration. Meanwhile, supplementing strategies with smart and equitable testing and establishing a pathogen genome surveillance network is equally important to shape the trajectory of the virus and mitigate disruptions to essential health service delivery.