Impact of ChAdOx1 nCoV-19 (Covishield™) Vaccination: How Long Will It Persist?

Table 2

Analysis of COVID-19 seropositivity among HCWs with prior history of COVID-19.

Time period for diagnosis of study participants as COVID-19 positive	Baseline seropositivity among HCWs (n = 42); N (%)	Mean IgG antibody index in three sampling points; Prior to 1st dose	Prior to 2nd dose	3 months after 2nd dose	Statistical comparisons
July-August 2020	7 (16.7)	3.6 ± 1.4	6.8 ± 0.9	7.5 ± 2.4	<0.001
September-October 2020	19 (45.2)	4.2 ± 1.8	7.3 ± 2.5	9.2 ± 2.7	<0.001
November-December 2020	16 (38.1)	7.1 ± 2.6	8.9 ± 2.6	10.4 ± 3.2	0.003

Calculated out of the total number of participants with prior history of COVID-19.