BHUBANESWAR: A total of 274 (0.015 per cent) breakthrough infections of Covid-19 have been detected among 1.8 million fully vaccinated persons who have completed 14 days after getting the second dose, in Odisha till mid-June.
A total of 361 cases were referred by different health facilities to Regional Medical Research Centre (RMRC), Bhubaneswar, for confirmation of infection and quantitative antibody estimation. Of them, 87 were excluded as they were either not fully vaccinated or found positive within 14 days of completing the second dose. Nasopharyngeal swab and serum samples from vaccinated individuals were collected from various healthcare facilities in the State between March 1 and June 10.
The study by RMRC scientists has revealed that 27 individuals (10 pc) with breakthrough infections required hospitalisation. There was no significant difference between Covaxin and Covishield recipient groups. Around 16.8 pc people among those infected were asymptomatic with no significant difference in the CT values between the symptomatic and asymptomatic. The median age for breakthrough infection among referred cases was 47 years.
“Only one person (Covishield recipient) died post infection during the study period but his death was not due to vaccination. A total of 258 (94.2 pc) individuals were found to be positive for SARS-CoV-2 IgG antibodies against spike protein,” said Dr Debdutta Bhattacharya, a scientist associated with the study.
The study found no significant difference between the antibody titres (concentration of antibodies) in terms of gender, occupation, hospitalisation, and symptom status. The most common symptoms found were fever (88.5pc), followed by cough (77.6 pc) and sore throat (59.6 pc). Comorbidities such as diabetes, hypertension, hypothyroidism and asthma were present in about 64 (23.3 pc) individuals.
Earlier a study on healthcare workers had found symptomatic breakthrough infections occurring in 15 persons (13.3 pc), out of which one required hospitalisation. The study on the variants of the breakthrough cases would help in understanding various mutations and its effect on the vaccine’s capacity in preventing severe illness, added Dr Bhattacharya. The pre-print of study has been published in science journal Research Square.