Waning natural and vaccine-induced immunity leading to reinfection with SARS-CoV-2 Omicron variant

• Published in: Human vaccines & immunotherapeutics Vol. 18; no. 6; p. 2127289
• Main Authors: Shete, Anita M., Patil, Deepak Y., Sahay, Rima R., Sapkal, Gajanan N., Deshpande, Gururaj R., Yadav, Pragya D.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 30.11.2022; Taylor & Francis Group
• Subjects: B.1; ChAdOx1 nCoV-19; Coronavirus – Letter; COVID-19 - prevention & control; Covishield; Humans; Letter to the Editor; Omicron; primary infection; reinfection; Reinfection - prevention & control; SARS-CoV-2; SARS-CoV-2 - genetics; Vaccines; primary infection; SARS-CoV-2; reinfection; Omicron; B.1; Covishield
• ISSN: 2164-5515; 2164-554X
• DOI: 10.1080/21645515.2022.2127289

We have investigated six COVID-19 recovered cases with two doses of Covishield vaccination followed by reinfection. The primary SARS-CoV-2 infection found to occur with B.1 and reinfection with Omicron BA.1 and BA.2 variants. The genomic characterization and duration between two infections confirms these cases as SARS-CoV-2 reinfection. The immune response determined at different time intervals demonstrated boost post two dose vaccination, decline in pre-reinfection sera post 7 months and rise post reinfection. In conclusion, it was observed that these cases got SARS-CoV-2 reinfection with declined hybrid immunity acquired from primary infection and two dose covishield vaccination. This findings suggests the need to protect the community through booster dose of vaccination and prevent further infections following personal hygiene and non-pharmaceutical interventions.