Publications
  • Evidence stemming from the CORSIP study shows that getting two doses of an mRNA vaccine 6-to-7-weeks apart produces higher levels of antibodies compared to two doses 3-to-4-weeks apart, as recommended by the manufacturers.

Grunau, B., Asamoah-Boaheng, M., Lavoie, P. M., Ehsanul Karim, M., Kirkham, T. L., Demers, P. A., Barakauskas, V., Citlali Marquez, A., Jassem, A. N., O'Brien, S. F., Drews, S. J., Haig, S., Cheskes, S., & Goldfarb, D. M. (2021). A Higher Antibody Response Is Generated With a 6- to 7-Week (vs Standard) Severe Acute Respiratory Syndrome Coronavirus 2 (SARSCoV- 2) Vaccine Dosing Interval. Clinical Infectious Diseases. https://doi.org/10.1093/cid/ciab938

  • The CORSIP study aimed to identify the optimal interval between mRNA vaccine doses to generate the maximum immune response. The research team found that 38 days or more between doses was associated with a higher concentration of antibodies than a short interval (defined as 30 days or less).

Asamoah-Boaheng, M., Goldfarb, D. M., Prusinkiewicz, M. A., Golding, L., Ehsanul Karim, M. E., Barakauskas, V., Wall, N., Jassem, A. N., Citlali Marquez, A., MacDonald, C., O’Brien, S. F., Lavoie, P., Grunau, B. (2022). Determining the optimal SARS-CoV-2 mRNA vaccine dosing interval for maximum immunogenicity. Cureus. https://doi.org/10.7759/cureus.34465

  • New findings emerged from CORSIP project 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.

Grunau, B., Golding, L., Prusinkiewicz, M. A., Asamoah-Boaheng, M., Armour, R., Citlali Marquez, A., Jassem, A. N., Barakauskas, V., O'Brien, S. F., Drews, S. J., Haig, S., Lavoie, P. M., & Goldfarb, D. M. (2022). Comparative 6-Month Wild-Type and Delta-Variant Antibody Levels and Surrogate Neutralization for Adults Vaccinated with BNT162b2 versus mRNA-1273. Microbiology Spectrum, 10, e02702-21. https://doi.org/10.1128/spectrum.02702-21

  • A study published in Microbiology Spectrum found that vaccinated and unvaccinated groups require different thresholds to achieve optimal test performance, especially for detecting COVID-19 within the preceding 9 months. Overall, specificity was significantly higher among unvaccinated, compared to vaccinated individuals.

Asamoah-Boaheng, M., Goldfarb, D. M., Barakauskas, V., Kirkham, T. L., Demers, P. A., Ehsanul Karim, M., Lavoie, P. M., Citlali Marquez, A., Jassem, A. N., Jenneson, S., MacDonald, C., & Grunau, B. (2022). Evaluation of the Performance of a Multiplexed Serological Assay in the Detection of SARS-CoV-2 Infections in a Predominantly Vaccinated Population. Microbiology Spectrum, 10, e01454-21. https://doi.org/10.1128/spectrum.01454-21

  • Extending the interval between COVID-19 vaccine doses was introduced in Canada to accelerate population coverage with a single dose. In research published in JAMA, researchers studied the vaccine-induced antibody levels in paramedics who were immunized with mRNA vaccines at differing dosing intervals. They show that longer durations between doses led to increased average antibody levels and higher neutralization potential. The “gain” in antibody levels with increasing the vaccine dosing interval was particularly advantageous for the Delta variant.

Grunau, B., Goldfarb, D. M., Asamoah-Boaheng, M., Golding, L., Kirkham, T. L., Demers, P. A., & Lavoie, P. M. (2022). Immunogenicity of Extended mRNA SARS-CoV-2 Vaccine Dosing Intervals. Journal of the American Medical Association, 327(3), 279-281. https://doi.org/10.1001/jama.2021.21921

  • CORSIP study researchers did not find that, during the pre-Omicron waves, paramedics were at higher risk of catching SARS-CoV-2 than a control group of blood donors. There is evidence, however, that unvaccinated paramedics got COVID more frequently, compared to unvaccinated blood donors.

Grunau, B., O'Brien, S. F., Kirkham, T. L., Helmer, J., Demers, P. A., Asamoah-Boaheng, M., Drews, S. J., Ehsanul Karim, M., Srigley, J. A., Sediqi, S., O'Neill, D., Drennan, I. R., & Goldfarb, D. M. (2022). A Prospective Observational Cohort Comparison of SARS-CoV-2 Seroprevalence Between Paramedics and Matched Blood Donors in Canada During the COVID-19 Pandemic. Annals of Emergency Medicine. https://doi.org/10.1016/j.annemergmed.2022.03.009

  • A study published in The Journal of Infectious Diseases shows that higher antibody levels against the original (wild-type) SARS-CoV-2 virus are associated with a significantly reduced risk of subsequent infections with SARS-CoV-2 variants, both preceding and during the Omicron era. The association, however, was weaker during the Omicron wave.

Asamoah-Boaheng, M., Goldfarb, D. M., Karim, M. E., O'Brien, S. F., Wall, N., Drews, S. J., Barakauskas, V., Jassem, A. N., & Grunau, B. (2022). The relationship between anti-spike SARS-CoV-2 antibody levels and risk of breakthrough COVID-19 among fully vaccinated adults. The Journal of infectious diseases, jiac403. Advance online publication. https://doi.org/10.1093/infdis/jiac403

  • CORSIP study researchers investigated the serum cross-reactivity between anti-spike IgG antibodies against SARS-CoV-2 and four common endemic coronaviruses (HCoVs). Higher anti-spike concentrations of certain HCoVs were associated with a higher SARS-CoV-2 antibody response, suggesting that pre-existing HCoVs immunity may bolster vaccine-induced immune response to SARS-CoV-2.

Asamoah-Boaheng, M., Grunau, B., Karim, M. E., Jassem, A. N., Bolster, J., Marquez, A. C., Scheuermeyer, F. X., & Goldfarb, D. M. (2022). Are higher antibody levels against seasonal human coronaviruses associated with a more robust humoral immune response after SARS-CoV-2 vaccination?. Frontiers in immunology, 13, 954093. https://doi.org/10.3389/fimmu.2022.954093

  • CORSIP researchers published a paper in Microbiology Spectrum that demonstrates a correlative relationship between live viral neutralizing antibodies – the gold standard for evaluating the effectiveness of antibodies to block infection – and other surrogate measurements of SARS-CoV-2 anti-spike, anti-RBD and anti-N antibodies. These latter measurements, such as high-throughput serological assays that can provide qualitative (yes/no) or quantitative (numerical) outputs are less time-consuming and labour-intensive.

Grunau, B., Prusinkiewicz, M., Asamoah-Boaheng, M., Golding, L., Lavoie, P. M., Petric, M., Levett, P. N., Haig, S., Barakauskas, V., Karim, M. E., Jassem, A. N., Drews, S. J., Sediqi, S., & Goldfarb, D. M. (2022). Correlation of SARS-CoV-2 Viral Neutralizing Antibody Titers with Anti-Spike Antibodies and ACE-2 Inhibition among Vaccinated Individuals. Microbiology spectrum, 10(5), e0131522. https://doi.org/10.1128/spectrum.01315-22

  • The sensitivity of the Roche anti-SARS-CoV-2 nucleocapsid assay was tested in the CORSIP study. The authors in the article published below addressed the question of whether the sensitivity of nucleocapsid assays is compromised in vaccinated populations, potentially due to less vigorous antibody responses. It found that the assay was equally sensitive regardless of an individual’s vaccination status and this held true if the participant was infected pre-Omicron or during the Omicron era.

Grunau, B., Tom, J., Asamoah-Boaheng, M., O'Brien, S. F., Drews, S. J., Sediqi, S., Lavoie, P. M., Barakauskas, V., & Goldfarb, D. M. (2022). Sensitivity of the Elecsys Nucleocapsid Assay for the Detection of Preceding SARS-CoV-2 Infections. Open forum infectious diseases, 9(8), ofac349. https://doi.org/10.1093/ofid/ofac349