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Updated: May 7, 2026
Protocol for Recombinant RBD-based SARS Vaccines: Protein Preparation, Animal Vaccination and Neutralization Detection
Published on: May 2, 2011
Phase I/II study of COVID-19 RNA vaccine BNT162b1 in adults
Mark J Mulligan1,2, Kirsten E Lyke3, Nicholas Kitchin4
1New York University Langone Vaccine Center, New York, NY, USA.
Insights
This study evaluated BNT162b1, an mRNA vaccine for COVID-19, in healthy adults. The vaccine demonstrated dose-dependent safety and induced significant neutralizing antibody responses, supporting further clinical development.
Area of Science:
- Vaccinology
- Infectious Diseases
- Immunology
Background:
- The COVID-19 pandemic, caused by SARS-CoV-2, necessitates urgent vaccine development.
- BNT162b1 is an mRNA vaccine candidate targeting the SARS-CoV-2 receptor-binding domain (RBD).
Purpose of the Study:
- To assess the safety, tolerability, and immunogenicity of BNT162b1 in a dose-escalation study.
- To determine the optimal dose for further clinical trials.
Main Methods:
- A placebo-controlled, observer-blinded, dose-escalation study involving 45 healthy adults (18-55 years).
- Participants received two doses of 10 μg, 30 μg, or 100 μg of BNT162b1, separated by 21 days.
- Safety, local reactions, systemic events, and immunogenicity (RBD-binding IgG and neutralizing antibodies) were measured.
Main Results:
- Local and systemic reactions were dose-dependent, generally mild to moderate, and transient.
- RBD-binding IgG concentrations and neutralizing antibody titers increased with dose and after the second vaccination.
- Geometric mean neutralizing titers reached 1.9-4.6 times those of convalescent sera.
- The 100 μg dose was not advanced due to increased reactogenicity without significant immunogenicity gains over the 30 μg dose.
Conclusions:
- BNT162b1 exhibits a dose-dependent safety profile and induces robust immunogenicity.
- The 30 μg dose demonstrated a favorable balance of reactogenicity and immunogenicity.
- These findings support the further evaluation of BNT162b1 as a COVID-19 vaccine candidate.
Abstract:
In March 2020, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1, a pandemic. With rapidly accumulating numbers of cases and deaths reported globally2, a vaccine is urgently needed. Here we report the available safety, tolerability and immunogenicity data from an ongoing placebo-controlled, observer-blinded dose-escalation study (ClinicalTrials.gov identifier NCT04368728) among 45 healthy adults (18-55 years of age), who were randomized to receive 2 doses-separated by 21 days-of 10 μg, 30 μg or 100 μg of BNT162b1. BNT162b1 is a lipid-nanoparticle-formulated, nucleoside-modified mRNA vaccine that encodes the trimerized receptor-binding domain (RBD) of the spike glycoprotein of SARS-CoV-2. Local reactions and systemic events were dose-dependent, generally mild to moderate, and transient. A second vaccination with 100 μg was not administered because of the increased reactogenicity and a lack of meaningfully increased immunogenicity after a single dose compared with the 30-μg dose. RBD-binding IgG concentrations and SARS-CoV-2 neutralizing titres in sera increased with dose level and after a second dose. Geometric mean neutralizing titres reached 1.9-4.6-fold that of a panel of COVID-19 convalescent human sera, which were obtained at least 14 days after a positive SARS-CoV-2 PCR. These results support further evaluation of this mRNA vaccine candidate.
