The recent (June 10) approval by the Indian Council of Medical Research (ICMR) to three med-tech companies to manufacture self-use rapid antigen test kits for Covid-19 has the capacity to become a vital weapon in India’s arsenal to fight the crushing pandemic unleashed by the deadly virus.

Such kits can become the silver bullet in the fight against the virus only if the government allows their use for prolific and weekly testing on-demand at home or where there is a mingling of people. To make this happen, the Indian government must take some speedy decisions.

For starters, the government needs to liberalize ICMR testing guidelines to enable universal weekly testing of asymptomatic individuals at varied sources as a public health intervention.

Present ICMR guidelines, on which states base their Covid testing strategies, permit rapid antigen tests only for those showing symptoms of the viral disease or those who have had direct contact with an infected person.

One of the key elements in the war against the virus is the ability to control its rapid spread. The government needs time for widespread vaccination and ramping up vaccine production. So it has to immediately come up with interventions to detect infectious and contagious asymptomatic individuals who are super-spreaders, before they become symptomatic. The do-it-yourself tests can do just that if they are used frequently on a mass scale unhindered by limitations of eligibility for testing.

Open up testing

To achieve this, the government will have to open up testing without any conditions instead of restricting it to those already infected or who have had contact with an infected person.

Unless the restrictions on testing are removed, grey areas will emerge on who can buy such kits, how many can be bought by individuals, schools, commercial organizations, offices and even hospitals, and stand in the way of prolific and frequent testing that can identify those carrying a high viral load even before they know it. This will help break the chain of virus transmission and reverse its uncontrolled spread - a must to overcome the pandemic.

According to doctors, a person starts to shed the virus and infect others a day or a day and a half before showing signs of being ill. He isolates only when infection manifests itself and tests positive through an RT PCR lab test. By then he has already unknowingly infected others and added to the chain of transmission. ICMR’s green signal for the manufacture of such kits is just a preliminary step to shore up missiles in the war against the spread of Covid-19 infection.

But it can prove to be a dud weapon unless the government guidelines are tweaked to make way for high-volume testing on-demand at least twice a week to identify infectious individuals who may be transmitting the virus.  

As the country moves to open up, there will be an increased mingling of people in public transport, schools, offices, shopping centers, restaurants, movie theatres, gyms and inter-state travel. A liberalized testing policy becomes imperative alongside mass vaccination and adherence to Covid behavior protocols. Large-scale testing at offices, schools, public places and at home is possible only with self-use kits that can be bought across the counter.

A kit contains a strip of paper coated with antibodies, a soft cotton swab for superficial scraping of the inside of the nose and a pre-filled tube of buffer solution. After a nose scrap, the swab is dipped in the solution which is allowed to drip on the paper strip. Within 15-30 minutes a band appears on the paper to indicate a negative or positive Covid test.

Less accurate but effective

The downside of tests by such kits is the accuracy of the results it gives. Dr. Ambarish Satwik of Delhi’s Ganga Ram Hospital, who is among those making a pitch for mass testing with the help of these kits, admits that such tests are not as sensitive as the RT PCR tests. But they are sensitive enough to detect the presence of Covid-19 in asymptomatic people unknowingly spreading the virus.

Noted epidemiologist Michael Mina, of Harvard T.H. Chan School of Public Health, says test at home kits have an 80 percent sensitivity in detecting the virus in asymptomatic individuals. Free access to the use of self-use kits in Germany, the US, the UK, Slovakia has shown a 70 per cent reduction in the prevailing infection rate. Germany has made tests by kits mandatory for entry to restaurants, gyms, concerts and theatres. Dr. Satwik feels schools and offices in India could well consider this option.  

Since labs conducting RT PCR tests have constraints of limited capacity, the time required to tabulate results, access and affordability, self-testing kits can be a tool to combat the pandemic. Affordability and availability will determine if self-use kits can reach a sizable number of people across the country. The government will have to consider bearing the burden for individuals in low-income groups and making them available in the hinterland. It is for the government to realize that the time for self-use kits has come.

(The writer is a Delhi-based senior journalist. The views expressed are personal. She can be contacted at rsaksena8@gmail.com)