Real-world impact of NVX-CoV2373 COVID-19 vaccine in immunocompromised individuals in South Korea

BACKGROUND: NVX-CoV2373 is a nanoparticle, protein-based COVID-19 vaccine. Individuals who are immunocompromised (IIC) are at high risk for infection and severe disease; however, real-world NVX-CoV2373 impact data in IIC are limited. METHODS: The objective of this study was to assess whether NVX-CoV2373 reduced the risk of SARS-CoV-2 infection and severe disease in IIC, compared to non-immunocompromised (non-IC) individuals. South Korean IIC aged ≥12 years who received a primary series, third dose, or fourth dose of NVX-CoV2373 were identified in The Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service (K-COV-N) database. IIC were propensity score matched to non-IC individuals to minimize potential confounding. Outcomes were any and severe SARS-CoV-2 infections, collected in cumulative 30-day risk windows through 180 days post vaccination in primary series and third- and fourth-dose groups. Adjusted hazard ratios (aHRs) measured relative vaccine impact by comparing outcomes between IIC and non-IC individuals across dose groups, overall, and by immunocompromising condition. RESULTS: A total of 755,727 doses of NVX-CoV2373 were administered from February-December 2022, with 400,435 IIC individuals included in this analysis. Through 180 days, aHRs (95% CI) for any SARS-CoV-2 infection were 1.10 (1.06-1.14), 1.05 (1.01-1.09), and 1.03 (1.02-1.05) for the primary series, third-dose, and fourth-dose groups; severe infection: 0.76 (0.52-1.12), 0.90 (0.53-1.51), and 1.11 (0.87-1.41), respectively. Risk estimates for any infection were relatively consistent across risk windows and among most immunocompromising conditions. CONCLUSION: A similar risk of medically attended SARS-CoV-2 infection between IIC and non-IC was observed with both a homologous primary series and homologous or heterologous third and fourth doses of NVX-CoV2373, as well as across a variety of immunocompromising conditions.