The additional authors declare having no conflict of interest. == Acknowledgements == The authors would like to thank all participants and the dedicated staff of the local centres and their respective biological resource centres, who continuously participated with enthusiasm in the cohort and rendered this research possible. applicable) based on the percentage of responders (positive for anti-Spike severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] IgG antibodies), geometric means of anti-Spike SARS-CoV-2 IgG antibodies (enzyme-linked immunosorbent assay) and proportion of participants with anti-SARS-CoV-2-specific neutralizing antibodies (in vitroneutralization assay for Meclizine 2HCl the original SARS-CoV-2 strain). All analyses were centralized. == Results == We included 4091 participants in this analysis: 2979 participants from specific sub-populations and 1112 settings. Only 522 (17.5%) participants from the specific populations received three doses like a primary vaccination routine. Patients living with human being immunodeficiency virus, malignancy and diabetes experienced high percentages of responders after two doses, whereas individuals with solid organ transplants, allogeneic hematopoietic stem cell transplants and Meclizine 2HCl hypogammaglobulinaemia experienced the lowest percentage of responders (35.9% [95% CI, 29.243.0], 57.4% [95% CI, 48.166.3] and 77.1% [95% CI, 65.686.3], respectively). In those who received the third dose, the percentage of responders reached 54.2% (95% CI, 42.965.2) (vs. 32.3% [95% CI, 16.751.4] after 2 doses) among those with solid organ transplants and 73.9% (95% CI, 58.985.7) (vs. 56.1% [95% CI, 46.265.7] after 2 doses) among those with hematopoietic stem cell transplants. Comparable results were found with anti-SARS-CoV-2-specific neutralizing antibodies. == Conclusions == A lower humoral response to COVID-19 vaccines was observed in the specific populations compared with that in the controls. The third dose of this vaccine in the primary regimen had a positive effect on the percentages of patients who developed anti-Spike IgG antibodies and specific neutralizing antibodies. Keywords:COVID-19, Efficacy, Humoral, Immunocompromised, Immunogenicity, Specific populations == Introduction == Specific populations, such as those of immunocompromised patients or patients with obesity, are defined as individuals at the risk of developing severe forms of infectious diseases Meclizine 2HCl and in whom there are concerns of potentially decreased immunogenicity and effectiveness of vaccines. Phase 3 studies on coronavirus disease 2019 (COVID-19) vaccines have provided little information on vaccine efficacy in specific populations. Initial real-life studies showed lower anti-Spike antibody responses [1,2], leading to lower vaccine efficacy compared with those in non-immunocompromised populations [[3],[4],[5],[6]]. Most of these studies were based on small sample sizes, with no standardized measures and control groups [1,2]. Many countries have recommended at least one additional dose in the primary vaccination regimen in immunocompromised populations, with the results showing convincing effects around the humoral response in small studies [7]. Detailed short- and long-term immune response assessments in these populations based on the number of doses of the vaccine received are warranted to inform reflections on tailored vaccine regimens. The ANRS0001S COV-POPART cohort study aimed at assessing the humoral immune responses to COVID-19 vaccines in 11 sub-groups of specific populations compared with those in a control group [8]. == Methods == == Study design and patients == ANRS0001SCOV-POPART (NCT04824651) is usually a multi-centre, prospective cohort study conducted in France to assess the immune response to COVID-19 vaccines routinely administered to specific populations as part of a national immunization campaign [8]. The study was conducted in 36 participating centres in France in collaboration with the I-reivac network, ten national learned societies and seven patients’ associations (France Rein, Transhpate, Fondation pour lAide la Recherche sur la Sclrose en Plaques (ARSEP Foundation), Meclizine 2HCl Collectif National des Associations d’Obses (CNAO), Fdration Francaise des Diabtiques (FFD), Association d’Entraide aux Greffs de Moelle Osseuse (EGMOS) and Traitements et Recherche Thrapeutique – 5 Collectif Hpatites Virales (TRT5 CHV)). Adults without a known history of COVID-19 and affected by solid cancer, solid organ transplant (SOT), allogeneic hematopoietic stem cell transplant (HSCT), chronic renal failure (stage 4 and 5 = glomerular filtration rate <30 mL/min/1.73 m2) with or Arnt without dialysis, multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSDs), inflammatory rheumatic diseases, systemic autoimmune diseases, hypogammaglobulinemia (primary and secondary), obesity (body mass index >30 kg/m2) or diabetes mellitus (both types 1 and 2) or patients living with human immunodeficiency virus (PLWHIV) and willing to be vaccinated as part of the national immunization campaign were included from 25 March, 2021, to 31 December, 2021. Patients might have been included before any vaccination, after the first dose or in the month following the second.
PDK1