Safety, immunogenicity, and breakthrough infections during 1-year follow-up after COVISHIELD™ vaccination among healthcare workers in a teaching institute in North India: A prospective longitudinal study
Background: A prospective longitudinal study was planned to assess immunogenicity, safety, and breakthrough infection rates among health care workers (HCWs) after COVISHIELD™ vaccination in a teaching institute in North India. Methods: A total of 518 HCWs were enrolled at baseline for receiving firs...
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| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wolters Kluwer Medknow Publications
2025-02-01
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| Series: | Journal of Family Medicine and Primary Care |
| Subjects: | |
| Online Access: | https://journals.lww.com/10.4103/jfmpc.jfmpc_935_24 |
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| Summary: | Background:
A prospective longitudinal study was planned to assess immunogenicity, safety, and breakthrough infection rates among health care workers (HCWs) after COVISHIELD™ vaccination in a teaching institute in North India.
Methods:
A total of 518 HCWs were enrolled at baseline for receiving first dose of COVISHIELD™, 429 continued participation for second dose, 415 followed up at 28 days after second dose, 405 at 6 months, and 403 at 1 year from February 2021 to November 2022. At each visit prior, 2 ml of blood sample was collected and plasma separated. Anti–SARS-Cov-2 IgG antibodies against spike protein were detected by Chemiluminescent Immuno-Assay on the VITROS 3600 platform (Ortho-clinical Diagnostics, NJ, USA). Data were analysed for 403 HCWs (completed all follow-ups), using Statistical Package for Social Sciences version 21.0.
Results:
The mean age of participants was 35.3 years (SD ± 11.11), and males were 50.2%. At baseline (N = 518), proportion of reactive HCWs was 25% (95% CI, 21–29%), which increased significantly to 92% (95% CI, 89–95%) after receiving first dose (N = 403), 95% (95% CI, 92–96%) after second dose (N = 403), and declined to 85% (95% CI, 83–93%) at six months (N = 403). At 1 year, reactivity increased to 89.3% (95% CI, 86–90%; P value < 0.0001). Fever was reported by 31.2% of HCWs, followed by pain at injection site (27.6%), malaise (16.4%), headache (3.7%), and dizziness (3.7%).
Conclusions:
Immunogenicity post-COVISHIELD™ vaccination increased after first and second doses but declined after 6 months and inclined after 1 year of the first dose. The safety profile was within acceptable limits. |
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| ISSN: | 2249-4863 2278-7135 |