The rigorous process at ICMR

Radhakrishnan Nair, a scientist who’s working with Pillai on RGCB’s rapid test, says synthesising the antigenic protein is easy enough if you know where to look. “Once you know the viral sequence of this particular coronavirus, you can isolate the antigenic protein. That’s what the antibody [in the blood] binds to in the test,” says Nair. Nair admits that this requires some expertise, because this strain of coronavirus has proteins in common with other strains that cause See SARS or MERS.

For Nair and Pillai, importing kits right now is not the answer. RGCB has tied up with a Thiruvanathapuram-based manufacturing unit, and will soon send a sample to NIV for approval. “We are trying to get the sensitivity up to 95% on the tests before that,” says Nair.

The plan, says Pillai, is to make these kits super affordable at Rs 275 ($3.6) apiece. The private lab owner, mentioned above, is trying to price the rapid test even lower, at Rs 150 ($1.9). Tiwari, of Vanguard, wants to price the tests between Rs 400-800 ($5.2-10.5), which includes a Rs 200-300 ($2.6-3.9) making cost. In comparison, companies like OZO claim high-quality kits, in the global market, are priced at $20 apiece.

“The antigenic material per test itself costs $5. The making cost is another $0.8. How can we sell the kit for less than $8-$10 in India without facing quality issues?” says Jain of OZO. On the one hand, claims Jain, global demand is raising prices for the antigenic material and finished kits. On the other hand, as a price-sensitive country, Indian officials are asking them to price the tests between $1.5-2.

Surveillance, not diagnosis

Once these tests enter the mass market, they could ease ICMR’s chokehold on testing. However, before that can happen, authorities must explain how they are to be used, and what their results signify. After all, rapid tests, unlike their PCR counterparts, aren’t really a diagnostic solution. “It’s a marker for exposure, rather than a marker for the disease,” explains Pillai. Unlike PCR tests which are supposed to have 100% sensitivity under ICMR guidelines, the accuracy bar for antibody tests usually hovers around 85-90% sensitivity.

At a population level, however, rapid antibody tests can have a completely different use. Rapid tests can be used as a sorting mechanism to screen health workers and high-risk patients (above 60 years and with comorbidities) for the virus. Rapid kits are also a surveillance tool at a community level, because they can be used to test larger samples sizes in one go.

The antibody test will also indicate which type of antibodies have been generated in an infected person. “The rise of the IgG antibody is a sign that the body has started to fight the infection,” says Nair. A large number of people with antibodies could indicate that at a population level, we’ve developed some immunity to the disease.

Their ease of use, however, can’t be taken lightly. In India, Nair says, there is little chance that this test will be sold or bought over-the-counter the way, say, a pregnancy kit would. The risk, he says, is in misinterpreting or suppressing the results of such a test. “If they test positive on a rapid kit, it’s possible they don’t report their infection for fear of being quarantined,” says Nair.

It’s also apparent that ICMR wouldn’t want such test data to be made public. For instance, Bengaluru-based company Bione, tried to retail these tests online and even began taking pre-orders for a Rs 2,499 ($33) antibody kit. They were quickly pulled up by the Drugs Controller General of India for selling unlicensed tests.

What is rapid, anyway?

Without an over-the-counter version, rapid tests are as likely to be under strict bureaucratic control as their PCR counterparts. How they are administered, who can access them, and the data they generate will still be under ICMR’s control.

That doesn’t mean testing for Covid-19 can’t be more rapid.

For instance, not everyone is convinced about antibody tests, even as a surveillance tool. A research group from the Indian Institute of Science (IISc) in Bengaluru, has eschewed their use in favour of PCR tests. The group, led by IISc scientist Sai Siva Gorthi, wants to expand access to Covid tests in tier-2 and tier-3 towns through mobile PCR testing vans.