One out of every five persons in Assam - 23.7 per cent of the population - has been exposed to coronavirus till mid-August. This is far less than what is required to develop herd immunity, the first ever seroprevalence survey conducted in the state has shown.
Seroprevalence refers to the percentage of individuals in a population who have antibodies to an infectious agent. The optimal level of exposure required to develop herd immunity is 50 per cent, according to the study.
Assam will, thus, have to continue to depend on conventional preventive measures to curb COVID-19 among its people.
"The survey was done between August 23 and September 26, 2020, and a total of 2,390 samples were collected," said a press statement from Srijanasom, a charitable organisation that has organised it in collaboration with Medicity Guwahati group of Clinics and Diagnostics.
The study, called Assessment of Anti-SARS CoV 2 Seroprevalence in Habitants of Assam, has been shared with Assam health department.
Participants from the 33 districts of Assam were tested during the survey as part of a larger effort to understand how widespread COVID-19 prevalence is in the state.
It found that, given the low level of the population's exposure to the disease at this stage, authorities cannot expect herd immunity to be a solution to tackle the pandemic.
"Till a vaccine comes up and a substantial population is immunised, we will have to observe context-specific containment measures like wearing of masks, hand hygiene, respiratory etiquette, avoiding unnecessary travel and crowded places," said Dr Jyotismita Pathak, head of policy and programme of Srijanasom.
Assam has 28,385 active COVID-19 cases, recording 816 deaths till today.