Archive · 11 Jun 2025
Tamil Nadu Sero-Survey: 97% Immunity Against COVID-19
Scientists checked blood samples in Tamil Nadu to see how many people had protection against COVID-19.
They found that 97% of people had antibodies, which help fight the virus.
This survey, done in April 2025, is the fifth one.
It looked at samples from older people in different districts.
High vaccination rates and previous infections from a weaker version of the virus helped build this protection.
Tamil Nadu's latest sero-survey shows 97% immunity against COVID-19.
The survey tested for SARS-CoV-2 IgG antibodies in blood samples.
The fifth phase of the survey, conducted in April 2025, included elderly individuals.
Samples were collected from six districts in Tamil Nadu.
Effective vaccination drives and Omicron sub-lineage infections boosted immunity.
- Who
- Directorate of Public Health and Preventive Medicine, Tamil Nadu
- What
- COVID-19 sero-survey results
- When
- April 2025 (survey conducted), Published on June 11, 2025
- Where
- Tamil Nadu (Chennai, Tiruvallur, Tiruvannamalai, Trichy, Dharmapuri and Kanyakumari districts)
- Why
- To assess the level of protective immunity against COVID-19
- Survey Phase
- Fifth
- Antibody Presence
- 97%
- Sample Type
- Blood samples
- Antibody Tested For
- SARS-CoV-2 IgG
- Sample Collection Month
- April 2025
- Survey Location
- Tamil Nadu
- Districts involved
- Chennai, Tiruvallur, Tiruvannamalai, Trichy, Dharmapuri and Kanyakumari
