Immunological response to the Covid-19 vaccine in specific populations

Inserm-ANRS

Odile Launay MD, PhD-AP-HP / Paul Loubet MD, PhD – CHU Nîmes / Linda Wittkop, MD, PhD-Bordeaux

COV-POPART is a French nationwide multicenter cohort study of specific populations for Covid-19 vaccination with prospective clinical and biological data collection. Serological tests with tests limits and seroneutralisation for the original SARS-CoV-2 strain are carried out centrally.
For some participants, in-depth immunology and virology study is conducted in addition. A linkage with the Health Data Hub (medico-administrative databases) to retrieve health data is planned. An ancillary pediatric cohort study has been added.

Multicenter national cohort study with prospective data collection and constitution of biologicals samples collections (biobanks).

Evaluate in a standardised way in each subpopulation the humoral immune response to Covid-19 vaccination :

• At 1, 6, 12, 24 months after the single injection (initial regimen with one injection),
• At the time of the second injection then at 1, 6, 12 and 24 months after the second injection of the vaccine (initial schedules with two or three injections) and,
• At 1 month after the third injection in participants receiving a third injection as part of their initial vaccination schedule, according to current recommendations.

• Humoral immunity at inclusion, at the time of the second injection (if applicable), 1 month after initial vaccination (if applicable), 1 month after the third dose (if applicable), 6 months, 12 months and 24 months after the single or the second dose of the initial vaccination :
  – Anti-Spike antibody (quantitative Elisa)
  – Anti-RBD antibodies (Elisa)
  – Proportion of participants with an Anti-SARS-CoV-2 anti-Spike IgG titer above a threshold defined from the control group of the COV-POPART cohort and also from the thresholds identified in the literature referring to thresholds corresponding to correlates of protection
  – Seroneutralization by standard in vitro neutralization test, for participants with positive test 1 (Elisa IgG Anti-SARS-CoV-2 anti-Spike) and/or test 2 (Elisa Anti-SARS-CoV-2 anti-RBD): neutralizing antibody titer and percentage of patients with SARS-CoV-2 specific neutralizing antibody titer greater than or equal to 20
  – Seroneutralization, by neutralization test on SARS-CoV-2 variants, in the first 50 participants included per subpopulation having had an Elisa test result (IgG Anti-SARS-CoV-2 anti-Spike and/or anti -RBD) positive 1 month after their second vaccine injection: titer of neutralizing antibodies specific for SARS-CoV-2 and percentage of patients with a titer of neutralizing antibodies specific for SARS-CoV-2 greater than or equal to 20 (the participants selected by this criterion are kept for the analysis on the variants at each follow-up point).
• Seroconversion or at least a two-fold increase in anti-Spike/anti-RBD antibody titers between the second and third injections in participants who received a third injection.

• 14 types of adult subpopulations: 11 patient subpopulations with a chronic condition of interest + 3 subpopulations in the control group.
• 11 sub-populations presenting a chronic condition of interest :
  – Patients treated or having been treated for less than 2 years due to cancer/solid tumor
  – Solid organ transplantation
  – Allogeneic hematopoietic stem cell transplantation
  – Chronic renal failure and dialysis
  – Systemic inflammatory and autoimmune diseases
  – Inflammatory rheumatic disease
  – Multiple sclerosis and Neuromyelitis optical diseases
  – Hypogammaglobulinemia
  – Diabetics (type I and II) obese or not
  – Obeses non diabetic
  – People living with HIV (HIV-1)
• 3 Control groups :
  – People free of the chronic conditions listed above or other pathologies / under treatment with a known influence on the immune response aged 18 to 74
  – People free of the chronic conditions listed above or other pathologies / under treatment with a known influence on the immune response aged 75 and over
  – Persons free of the chronic conditions listed above or other pathologies / under treatment with a known influence on the immune response and vaccinated with a 1st injection of Astra-Zeneca AZD1222 vaccine who will be vaccinated with a 2nd injection of Pfizer BNT162b2 mRNA vaccine
• 1 pediatric ancillary study: children from 5 to 17 years old.

Evaluate in a standardised way in each subpopulation the humoral immune response to Covid-19 vaccination

6108 adult participants and 149 child participants

France, 43 sites

33 months

• Ministère des Solidarités et de la Santé
• Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation

Methodology, Coordination, Data management, Statistics and monitoring

https://clinicaltrials.gov/ct2/show/NCT04824651