One-month humoral response following two or three doses of mRNA Covid-19 vaccines as primary vaccination in specific populations in France: first results from the ANRS0001S COV-POPART cohort

International audienceObjectives: We aimed to investigate the one-month humoral response to two or three doses as primary vaccination in specific populations compared to healthy adults.Methods: ANRS0001S-COV-POPART (NCT04824651) is a French nationwide multicenter prospective observational cohort study assessing the immune response to Covid-19 vaccines routinely administered to 11 subgroups of patients with chronic conditions and two control groups. Patients and controls who had received at least two vaccine doses and whose results at one month after the second dose were available have been included. Humoral response was assessed at 1-month post first dose, post second dose and post third dose (if applicable), through the percentage of responders (positive anti-Spike SARS-CoV-2 IgG antibodies, geometric means of anti-Spike SARS-CoV-2 IgG antibodies (ELISA) and proportion of participants with anti-SARS-CoV-2-specific neutralizing antibodies (in vitro neutralization assay for the original SARS-CoV-2 strain). All analyses were centralized.Results: We included 4091 participants in this analysis: 2979 participants from specific subpopulations and 1112 controls. Only 522 (17.5%) of the specific populations received 3 doses as primary vaccination regimen. Patients living with HIV, cancer and diabetic patients had high rates of responders after two doses while solid organ transplant (SOT), allogeneic hematopoietic stem cell transplant (HSCT) and hypogammaglobulinemic patients had the lowest percentage of responders (35.9% [95%CI: 29.2; 43.0], 57.4% [48.1; 66.3]) and 77.1% [65.6; 86.3] respectively). In those who received a third dose, the rate of responders reached 54.2% [42.9-65.2] (vs. 32.3% (16.7-51.4) after 2 doses) in SOT and 73.9% [58.9-85.7) (vs. 56.1% [46.2-65.7] after 2 doses) in HSCT. Similar results were found with anti-SARS-CoV-2-specific neutralizing antibodies.Conclusions: Lower COVID-19 vaccine humoral response was observed in specific populations compared to controls. A third dose of vaccine in the primary regimen had a positive effect on both percentages of patients who developed anti-Spike IgG antibodies and specific neutralizing antibodies

Sotrovimab therapy elicits antiviral activities against Omicron BQ.1.1 and XBB.1.5 in sera of immunocompromised patients [letter]

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