Serological Response to Antipneumococcal Vaccination and Impact on Streptococcus Pneumoniae Nasal Carriage in HIV Adults
Condition: HIV Infection; Pneumococcal Infections
MeSH terms: Infections; Communicable Diseases; Pneumonia; Pneumonia, Pneumococcal; Pneumococcal Infections
Study type: Interventional
Phase: Phase 3

Summary: 
      S. pneumoniae is frequently isolated from nasal swabs of healthy subjects, but it can also
      cause severe diseases (pneumonia, bacteraemia, meningitis and sepsis).HIV-infected subjects
      are more sensitive to invasive diseases and recurrent infection than the general population.
      Nasal carriage is the main pathogenetic feature for invasive disease: bacteraemia is more
      frequent in carriers, HIV+ patients are constantly colonized by the same pneumococcal strain
      and their nasopharyngeal isolates have features similar to subsequent invasive strains. A
      23-valent polysaccharide vaccine (PPV23) has long been available and recommended in the HIV+
      population as prophylaxis for invasive disease. Studies regarding efficacy of PPV23 in HIV+
      are controversial and highlight that immune response induced by PPV23 in HIV+ is poor and an
      hyporesponsiveness to repeated polysaccaridic antigens stimulation can occur. Moreover, PPV23
      seems not to affect pneumococcal carriage status and could lead to emergence of non-vaccine
      serotypes. The conjugation of pneumococcal capsular polysaccharides to carrier proteins
      results in an improved T-cell dependent immune response, characterized by increased antibody
      concentrations and induction of T and B memory cells, with a demonstrated higher efficacy in
      children. A heptavalent vaccine conjugated with diphtheria toxoid (PCV7) is approved in
      Europe since 2001 and is effective in reducing incidence of invasive disease by vaccine
      serotypes (4, 6B, 9V, 14, 18C, 19F, 23F), in both children and adults, due to effect of herd
      immunity. A PCV13 formulation has recently been developed, covering PCV7 serotypes plus 1, 3,
      5, 6A, 7F and 19A. PCV13 revealed the same safety profile as PCV7 in pediatric patients, that
      are the main target of conjugate vaccines licensure. Some trials showed a better antibody
      response in terms of quantity and quality in HIV + adults by using PCV7 as compared to PPV23.
      However these data were not unequivocally confirmed in further studies on the use of PCV7
      alone or in combination with PPV23. The first trials of PCV13 use in adults showed the same
      or even better response compared to PPV23, with a safety and tolerability similar to PCV7.
      PCV13 in HIV+ adults is a promising candidate prophylactic measure for pneumococcal
      infections. The purpose of this study is to evaluate serological response and prevalence of
      nasopharyngeal colonization by S. pneumoniae in HIV+ non-hospitalized adults, following
      vaccination with 2 doses of PCV13.
    


Intervention name(s): pneumococcal conjugate 13 valent vaccine
Intervention type(s): Biological
Intervention description(s): Pneumococcal polysaccharide conjugate vaccine(13-valent adsorbed) conjugated to CRM197 carrier protein and adsorbed on aluminum phosphate (0.125 mg of aluminum).
Pharmaceutical form: suspension for injection. Dosage: 0.5 ml, containing 2.2 g of polysaccharide for serotypes 1, 3, 4, 5, 6A, 7F, 9V, 14, 18C, 19A, 19F, 23F, and 4.4 micrograms for serotype 6B.
Prevenar 13 is administered in two doses,each of 0.5 ml, with an interval of 2 months, injected intramuscularly in the deltoid muscle of the arm.
Other intervention name(s): Prevenar13
Intervention MeSH terms: Heptavalent Pneumococcal Conjugate Vaccine
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: HIV; Streptococcus pneumoniae; 13-valent conjugate pneumococcal vaccine; Vaccine; Immunological Response; Pneumococcal Carriage