Phase 2/3 Study Shows Robust Immunogenicity of NVX-CoV2601 in Vaccine-Naive Individuals with Prior SARS-CoV-2 Infection

Introduction

Variants of SARS-CoV-2 have evolved rapidly, necessitating updates to vaccine compositions. The WHO, European Medicines Agency, and US FDA recommended updating COVID-19 vaccines to a monovalent XBB.1.5 composition for the 2023–2024 season. NVX-CoV2601, based on the same rS protein technology as the authorized prototype NVX-CoV2373, was developed in response to this guidance.

Study Design and Participants

The phase 2/3, open-label 2019nCoV-313 study evaluated the immunogenicity and safety of NVX-CoV2601 in two populations: previously vaccinated adults and vaccine-naive adults with prior SARS-CoV-2 infection. The study aimed to assess the noninferiority of nAb responses elicited by NVX-CoV2601 in vaccine-naive participants compared to vaccinated participants.

Results

The study met its co-primary objectives, showing that NVX-CoV2601 elicited a noninferior nAb response in vaccine-naive participants compared to vaccinated participants. Robust increases in nAbs were observed in both groups, with a greater increase in the vaccine-naive group. The safety profile of NVX-CoV2601 was consistent with that of the prototype vaccine, NVX-CoV2373, with no new safety signals identified.

Discussion

The findings support the use of single doses of NVX-CoV2601 to elicit immunity against SARS-CoV-2, regardless of prior vaccination history. The study highlights the importance of updating COVID-19 vaccines to align with predominantly circulating strains and supports recommendations for the spring 2024 vaccination campaign in vulnerable individuals.

Conclusion

A single dose of NVX-CoV2601 is effective in eliciting robust immunogenicity in vaccine-naive individuals with prior SARS-CoV-2 infection, offering a promising approach to COVID-19 vaccination amidst high population-wide seroprevalence.