Mass antibody testing key to calibrated exit from lockdown

Prime Minister Narendra Modi has steadily scaled up his government's response to the coronavirus disease pandemic, starting with the screening of international passengers on January 17; following up with a three-week nationwide lockdown on March 25; and forming 11 high-level empowered groups to reinforce health care facilities, bring the economy back on track, and mitigate problems faced by citizens.

On April 4, Modi underlined the need for more hospitals, isolation and quarantine facilities, training of personnel for testing and critical care, medical equipment and personal protective gear for health care workers, and on April 6, sought suggestions from the council of ministers on a "calibrated" exit from the lockdown.

In this context, outlined below an innovative strategy for lifting the lockdown.

India's health management system is ready to begin antibody testing. Biomedical companies can upscale the manufacturing of kits under the supervision of, and quality certification by the Indian Council of Medical Research (ICMR). People with IgG antibodies, found in the blood and lymph fluid, whether or not they had suffered Covid-19, are immune, and, they can safely return to normal activities.

They will not get infected, and cannot transmit infection to others. Antibodies are of two kinds, IgM and IgG. In simple terms, IgM antibody signals current infection and IgG antibody records past infection and immunity.

The experience everywhere is that a large proportion of people with infection have no illness or only very mild symptoms, not fulfilling the clinical criteria of Covid-19 diagnoses. Unless tested with a PCR (polymerase chain reaction) test or IgM antibody test, they will remain undetected and not be counted as infected.

The mainstay of my strategy is systematic, well-designed, and widespread antibody testing of individuals, and certifying those who are antibody positive as exempted from lockdown. This is one form of "calibration."

Testing can be initiated in foci of selected geography, and centrifugally expanded. The field methodology can be designed by the responsible empowered group. This exercise can be continuous and ongoing. In communities already tested, it must be repeated periodically, say at intervals of 2-3 weeks, targeting those who were previously antibody-negative.

Antibody-positive persons are the newly recruited workforce in rebuilding economic activities. All data must be captured, stored, and made available to the concerned authorities of local and state governments.

A registry of antibody-positive healthy adults who are willing to be plasma donors must also be established along with antibody testing. Their plasma is an additional therapeutic item in the health care armamentarium for treating those at risk of severe illness with Covid-19.

Medical experts can develop the criteria for selecting such patients. The empowered group concerned with health care can design the modus operandi from A to Z, without delay.

Let me add that universal mask-wearing ought to be a necessary condition for lifting of lockdown. Ideally it should have preceded the lockdown. There are still a few days left under lockdown, and the policy of universal mask-use must be mandated as soon as possible. If the Union government delays action, state governments must take leadership.

As families stay confined in their own homes, they can stitch masks using old clothes. You do not need sewing machine; hand stitching is good enough.

The antibody testing survey has another major benefit. If designed well, it will inform us of the magnitude of the prevalence of Sars-CoV-2 infection. That is an invaluable piece of information that will guide future war tactics.