Publication date: Jan 01, 2026
The use of measured immune responses in informing risk of breakthrough COVID-19 infection and infection outcomes after vaccination against SARS-CoV-2 in clinically vulnerable patients has not been applied clinically. The aim of this study was to investigate the association between measured vaccine immunogenicity and vaccine effectiveness in clinically vulnerable populations. PubMed, MEDLINE, EMBASE, and Cochrane Library. Studies published between March 2020 and January 2025, which reported data on COVID-19 vaccine immunogenicity (antibody and T-cell) and subsequent infection outcomes. Patients defined as clinically vulnerable by QCOVID criteria, who had received at least the primary course of COVID-19 vaccination. The Newcastle-Ottawa Quality Assessment Scale was used to assess the risk of bias. A random effects meta-analysis model was used to pool relative risks of COVID-19 breakthrough infection (BTI), hospitalization, and death. Unadjusted data were used for the primary analysis due to the lack of adjusted data available in individual studies. We identified 3305 articles, of which 45 observational studies were included in the review. Negative antibody response following COVID-19 vaccination was associated with higher risks of BTI (Relative Risk (RR), 1. 82 (1. 45-2. 29), p
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | infection |
| disease | MESH | breakthrough COVID-19 infection |
| disease | MESH | COVID-19 |
| disease | MESH | death |
| disease | MESH | included |