Study of seroprevalence of SARS-CoV-2 in Kazakhstan.

This study aimed to analyse the seroprevalence of SARS-CoV-2 in Kazakhstan. This is a cross-sectional study of adult population in Kazakhstan for the period from October 2021 to May 2022. For the study, 6 720 people aged 18 to 69 were recruited (from 17 regions). The demographic data were collected and analysed. Gender was evenly distributed (males 49.9%, females 50.1%). Women exhibited a higher seroprevalence than men (IgM 20.7% vs 17.9% and IgG 46.1% vs 41.5%). The highest prevalence of IgM was found in the age group of 30-39. However, the highest prevalence of IgG was detected in the age group of 60-69. The seroprevalence of IgG increased across all groups (from 39.7% in 18-29 age groups to 53.1% in 60-69 age groups). The odds for a positive test were significantly increased in older age groups 50-59 ( < 0.0001) and 60-69 ( < 0.0001). The odds of a positive test were 1.12 times higher in females compared to males ( = 0.0294). The odds for a positive test were significantly higher in eight regions (Astana, Akmola, Atyrau, Western Kazakhstan region, Kostanai, Turkestan, Eastern Kazakhstan region, and Shymkent) compared to Almaty city. The odds of a positive test were three times higher in Astana and the Western Kazakhstan region than in Almaty city. In urban areas, the odds of a positive test were 0.75 times lower than in rural areas ( < 0.0001). The study's results showed an adequate level of seroprevalence (63%) that exceeds the essential minimum of herd immunity indicators in the country. There was significant geographic variability with a higher prevalence of IgG/IgM antibodies to SARS-CoV-2 in rural areas.