Pertussis Immunization During Pregnancy & HIV Infection
Condition: Immunization; Infection; Pertussis; HIV-1-infection; Pregnancy
MeSH terms: Infections; Communicable Diseases; HIV Infections; Whooping Cough
Study type: Observational

Summary: 
      The impact of chronic HIV infection and pregnancy on different aspects of the humoral
      response to pertussis immunization with the TDaP vaccine will be studied. The parameters will
      be measured in 3 groups (HIV-infected pregnant, HIV-uninfected pregnant and HIV-uninfected
      non pregnant) at different time points before and after immunization (7-10 days, 30 days and
      at delivery). The transfer ratio and the quality of maternal antibodies will be studied in
      cord blood.
    

Detailed description: 
      Despite the growing importance of maternal immunization in the control of infectious
      pathogens in early life, the impact of pregnancy on vaccine immunogenicity remains poorly
      understood. Evidence suggests that pregnancy may influence the quality of the antibody
      response to vaccines. Pregnancy is associated with modifications in the glycosylation profile
      of immunoglobulins G (IgG). Different patterns of glycosylation are associated with
      differential regulation of the effector functions of IgG such as antibody-dependent cell
      cytotoxicity, complement activation or antibody dependent phagocytosis. Whether similar
      modifications affect vaccine-induced IgG in pregnant women is unknown.

      HIV infection is associated with important alterations in B cells and antibodies. Although
      antiretroviral therapy partly corrects the proportions of memory B cells (MBC) subsets, it
      does not restore B cell responses to vaccines, measured as seroconversion rates and antibody
      persistence. Reduced IgG responses to vaccines have been observed in HIV-infected pregnant
      women but the impact of HIV on the quality of vaccine-induced IgG has not been reported. On
      the other hand, HIV infection in pregnancy has a strong impact on the transfer of maternal
      IgG to the newborn, possibly as a consequence of hypergammaglobulinemia and immune
      activation.

      The investigators will:

        1. Assess the respective impact of pregnancy and HIV infection on the magnitude and quality
           of B cell and antibody responses to pertussis immunization with the TDaP vaccine.

        2. Assess the impact of HIV infection and of the timing of maternal immunization on the
           transplacental transfer and on the quality of pertussis-specific IgG in the newborn.
    

Intervention name(s): TDaP
Intervention type(s): Biological
Intervention description(s): Tetanus, Diphteria and Acellular Pertussis vaccine (Boostrix)
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Recruitment at the Pre-natal clinic for pregnant women (HIV-infected or uninfected) on
        voluntary basis Recruitment at the Travel & Vaccine Clinic for HIV-uninfected non-pregnant
        women
      
Biospecimen description: 
      -  PBMCs

        -  Serum