Immunity level 87% against cov -2 in Himachal Pradesh

Shimla: A sero survey was conducted by NHM in collaboration with NIE, Chennai, WHO and medical colleges in the State. The population based survey was conducted during June-July, 2021 to estimate the proportion of population who had developed antibodies against SARS-CoV-2. A total of 4822 participants of six and six plus age group participated in the survey. A minimum of 400 individual were enrolled from each district to ensure representation of all the districts in the State.

Out of the total 4822, 437 participants were between 6-9 years, 939 participants were between 10-17 years, 2005 participants were between 18-44 years, 962 participants were between 45-60 years and 479 participants were more than 60 years. There were 2218 males and 2594 females and 10 others who participated in the survey.

The clusters of participants were chosen by the scientific method. The teams in the blocks went house to house of the selected participants to collect the blood samples and fill in the questionnaire developed by NIE, Chennai. These samples were then sent to the medical colleges in the State. All the government medical colleges along with MMU,Kandaghat and AIIMS Bilaspur participated in testing these samples for the antibodies against COVID. The samples were tested with the help of testing kits provided by WHO. It was seen that 1369 of the participants had been tested for COVID 19 and out of these 164 were found positive. In the sample 1724 participants had received first dose of the COVID vaccination and 1629 had received second dose of COVID vaccination.

A total of 4079 individuals had antibodies against SARS-CoV-2, which after scientific calculations and adjustments can be interpreted as “Prevalence of antibodies in 87.5% cases). The Districts reported immunity ranging from 76.1% (Una) to 95.6% (Kinnaur). It was seen that the immunity was present amongst the children who participated in the study. 53.6% aged 6-9 years and 61.5% aged 10-17 years)had developed immunity against COVID. However 98% of adults had developed immunity. It was also found that the immunity was higher among vaccinated individuals. 95.4% of the people who were vaccinated with the first dose and 97.6% people who were vaccinated with the second dose were found to have immunity against COVID. However, only 71.5% of the people who had taken no vaccination had immunity.

The detailed analysis of the immunised population on the basis of different parameters and district wise distribution are given in the tables below:

Table1: District wise Immunity (%) of immunoglobulin antibodies against severe acute respiratory syndrome coronavirus-2 infection, Himachal Pradesh,

Table 2: Sero-prevalence of antibodies by selected characteristics

A large proportion of the population i.e. 87% that participated in the study had antibodies against SARS-CoV-2. This immunity can be attributed to the vaccination taken by the participants in the study. The immunity in others could be the result of their exposure to the COVID infection.

This study clearly indicates that vaccination has played a major role in development of antibodies in the individuals against COVID. Hence it is recommend that all eligible individuals should come forward for COVID vaccination and ensure complete vaccination by taking both the doses. Till then it is advisable to follow COVID appropriate behaviour.