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Correlation between specific antibody response to wild-type BNT162b2 booster and the risk of breakthrough infection with omicron variants: Impact of household exposure in hospital healthcare workers.
- Source :
-
Vaccine . Oct2023, Vol. 41 Issue 45, p6672-6678. 7p. - Publication Year :
- 2023
-
Abstract
- • Post-BNT162b2 booster anti-spike IgG titers of healthcare workers were measured. • SARS-CoV-2 exposures and breakthrough infections were recorded during an omicron epidemic. • Post-booster IgG titers were inversely correlated with a SARS-CoV-2 infection risk. • Household exposure was an important source of SARS-CoV-2 infection for healthcare workers. • Exposure with IgG titers of <3,000 AU/mL increased the risk of breakthrough infection. The emergence of omicron variants exhibiting antigenic changes has led to an increase in breakthrough infection among individuals with a wild-type SARS-CoV-2 vaccine booster. The correlation between post-booster spike-specific antibodies and omicron infection risk remains unclear. This prospective cohort study included SARS-CoV-2-naive healthcare workers with three-dose BNT162b2. Post-booster spike-specific IgG and interferon-γ levels were measured. Breakthrough infection was documented during a 10-month omicron-predominant period. Household and healthcare contacts were followed to identify subsequent infections. The IgG titers were additionally measured at the end of follow-up, and the titers at exposure were estimated from the two-point titers. Of 333 participants, 89 developed infection, of whom 37 (41.6 %) were household contacts. Kaplan-Meier curves indicated that higher IgG titers were significantly correlated with lower cumulative infection incidence (p = 0.029), whereas the interferon-γ levels were not (p = 0.926). Multivariate Cox analysis showed that increasing IgG titers were associated with a reduced hazard ratio (HR) of 0.26 (95% CI, 0.12–0.55). Household exposure posed a greater infection risk than healthcare exposure (HRs, 11.24 [6.88–18.40] vs. 2.82 [1.37–5.44]). The difference in geometric mean IgG titers of infected and uninfected participants was significant among household contacts (20,244 AU/mL vs. 13,842 AU/mL, p = 0.031). Estimation of IgG titers at exposure showed a significantly higher infection incidence in those exposed with titers of <3,000 AU/mL than in those with higher titers (79.2 % vs. 32.3 %, p < 0.001). Spike-specific antibodies induced by a wild-type SARS-CoV-2 vaccine booster are suggested to be effective in protecting against omicron infection. Household exposure would be a significant source of infection for hospital healthcare workers. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0264410X
- Volume :
- 41
- Issue :
- 45
- Database :
- Academic Search Index
- Journal :
- Vaccine
- Publication Type :
- Academic Journal
- Accession number :
- 173010894
- Full Text :
- https://doi.org/10.1016/j.vaccine.2023.09.051