Grunau B, Golding L, Prusinkiewicz MA, Asamoah-Boaheng M, Armour R, Citlali Marquez A, Jassem AN, Barakauskas V, O’Brien SF, Drews SJ, Haig S, Lavoie PM, Goldfarb DM. Comparative 6-month Wild-Type and Delta-Variant Antibody levels and Surrogate Neutralization for Adults Vaccinated with BNT162b2 vs. mRNA-1273. Microbiol Spectr 2022 Mar 7:e0270221. doi: 10.1128/spectrum.02702-21.
The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.
New findings emerged from the CITF-funded COVID-19 Occupational Risks, Seroprevalence and Immunity among Paramedics (CORSIP) project led by Dr. Brian Grunau based at the University of British Columbia. They show that participants who were vaccinated with two doses of the Moderna vaccine have better protection, six months after the first dose, at blocking the Delta variant of SARS-CoV-2 from successfully binding to cells. This, compared to those who received two doses of Pfizer-BioNTech. The study is published in Microbiology Spectrum.
- Those vaccinated with Moderna Spikevax demonstrated higher IgG and total antibody levels against the spike protein of SARS-CoV-2 six months after their first dose, compared to those vaccinated with the Pfizer-BioNTech Comirnaty vaccine.
- Those who received Moderna also exhibited higher receptor binding domain (RBD) antibody levels compared to those who received Pfizer.
- The Moderna vaccine was also found to produce antibodies with a greater ability to block the binding of the SARS-CoV-2 spike (from the original strain and several Delta subtypes) to the angiotensin-converting enzyme 2 (ACE2) receptor on human cells – the key first step in establishing infection – compared to Pfizer.
The findings were based on 571 CORSIP study paramedics, of whom 475 (83%) received two doses of Pfizer and 96 (17%) received two doses of Moderna. The mean length of time between the two doses was about seven weeks. None of the study participants had a previously documented SARS-CoV-2 infection.
Learn more about the CORSIP study here.