A new sero-survey conducted by the Ahmedabad Municipal Corporation showed that 23.24% of samples had antibodies against coronavirus, indicating that the city has not developed a herd immunity, an official said on Wednesday.
Another survey, conducted to find the prevalence of antibodies among those who have recovered from COVID-19, revealed that 40% of such people did not have the antibodies, he said.
Bhavin Solanki, Medical Officer, AMC, said 23.24% of 10,000 samples showed presence of antibodies, which was an increase of 5.6 percentage points over the sero-survey in July, which had found positivity of 17.68%.
A sero-survey involves testing of blood serum to check the prevalence of antibodies against infection.
The latest findings indicate that the city is far from developing a herd immunity which requires 70-80% of population developing anti-bodies, Solanki said.
“The 5.6% increase in positivity shows that multidimensional steps taken by the AMC have yielded results in controlling the spread of the virus,” he said.
“23.24% positivity shows that we are far from developing any herd immunity, for which the positivity should be 70-80%,” he said.