Serological survey begins in a week to measure immunity level in state

Serological survey helps in measuring the exposure of a community to a disease (Covid-19 in this case) and detecting how many individuals developed antibodies to fight the virus after getting infected

With per day case count increasing rapidly in Punjab for the past two weeks, the state health authorities have decided to conduct ‘serological survey’ to check exposure of people of the state to the disease and the level of immunity they may have developed.

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Serological survey helps in measuring the exposure of a community to a disease (Covid-19 in this case) and detecting how many individuals developed antibodies to fight the virus after getting infected. A similar survey that covered 21,387 people in Delhi recently pointed to exposure of nearly 25% of the population to the virus already.

As per the plan, Punjab will cover more people as compared to Delhi to make the survey widespread and more accurate.

As per state’s nodal officer for Covid-19 Dr Rajesh Bhaskar, arrangements are being made to start a rapid sero survey in a week’s time.

“Special kits are being procured to carry out the tests for the survey as per the ICMR guidelines. The outcome of this survey will prove helpful in policy making to tackle the virus by getting an idea about herd immunity,” said the nodal officer.

As per health experts, herd immunity is a stage of a pandemic when people get protected from the infection because majority of those around them have already developed immunity against the infection.

As most of the patients hit by the virus remain asymptomatic, experts feel, in absence of testing, the virus may have already contracted many more without making any changes in their health because they have strong immunity.

As per Indian Council of Medical Research (ICMR’s) guidelines sent to states to conduct these surveys, the tests for the sero survey are conducted through an enzyme linked assay (EIA) using ELISA (enzyme-linked immunosorbent assay) testing kits.

The ICMR has already permitted sampling of patients who are ailing from other diseases, individuals in containment zones, essential services providers, migrants, prisoners and people living in compact slums for the sero survey.

As per the nodal officer, in a previous such survey in the state in May recorded mere 0.34% positive cases.

Jalandhar lab to conduct antibody test

The health department has already permitted a private lab in Jalandhar to conduct antibody ELISA test. However, the testing has been stopped for time being because of confusion over outcome of the tests.

“When this antibody testing shows positive, it means that a particular person has already been exposed to the virus. However, due to lack of knowledge on the issue, in some instances, the subjects were marked as Covid positive because their antibody tests came out to be positive. Because of this, we stopped the testing for the time being to avoid unnecessary confusion,” state’s nodal officer said.

HERD RESISTANCE A similar survey in Delhi covering 21,387 random individuals recently pointed to 25% of them having developed antibodies against the virus; Punjab has plan for a bigger survey