Immunogenicity of 13-valent pneumococcal conjugate vaccine among children with underlying medical conditions

Immunization for Children Living With HIV: A Scoping Review

BACKGROUND

Immunosuppression secondary to human immunodeficiency virus (HIV) increases the risk of vaccine-preventable diseases in children living with HIV (CLHIV). Although vaccines are cost-effective interventions, their efficacy, immunogenicity, safety, and persistence of post-vaccination immunity in CLHIV receiving antiretroviral therapy (ART) is unclear. We aimed at identifying existing scientific evidence on immunization of CLHIV generated in the last 10 years to identify the need for a systematic review.

METHODS

Studies were identified using a broad search strategy applied in multiple databases. Included studies involved CLHIV aged 0-10 years and presented outcomes on safety, efficacy, effectiveness, immunogenicity, and use of booster vaccines.

RESULTS

Nineteen publications were identified. There was variable immunogenicity to and efficacy of vaccines by HIV and ART status. All vaccines were safe.

CONCLUSION

The heterogeneity of available studies makes it complex to do a systematic review and meta-analysis. A more uniform approach to sampling and follow-up in future studies would make comparison and interpretation of results more robust.

Streptococcus pneumoniae Nasopharyngeal Carriage among PCV-10-Vaccinated HIV-1-Infected Children with Maintained Serological Memory in Ethiopia

Streptococcus pneumoniae (S. pneumoniae) vaccines have substantially reduced the burden of invasive pneumococcal diseases (IPDs) worldwide. Despite high coverage with S. pneumoniae vaccination, upper-respiratory-tract colonization by S. pneumoniae is still common. We assessed maintenance of serological responses to S. pneumoniae serotypes included in PCV-10 by ELISA in HIV-1-infected children (n = 50) and age-matched controls (n = 50) in Ethiopia. We isolated S. pneumoniae in nasopharyngeal swabs and determined S. pneumoniae serotype by whole genome sequencing (WGS). Comparable levels of S. pneumoniae serotype-specific IgG concentrations were detected in plasma of HIV-1-infected children and matched controls, with geometric mean concentrations (GMCs) consistently higher than the protective threshold for PCV-10 serotypes of 0.35 μg/mL. We isolated S. pneumoniae from 38 (out of 97) nasopharyngeal swabs, 25 from HIV-1-infected children and 13 from controls. WGS based serotyping revealed 22 known S. pneumoniae serotypes and 2 nontypeable (NT) isolates. Non-PCV-10 serotypes represented >90% of isolates. We showed that HIV-1-infected children and matched controls in Ethiopia carry a level of maintained serological memory to PCV-10 considered protective for IPDs. We identified a higher proportion of nasopharyngeal carriage with highly pathogenic S. pneumoniae non-PCV strains among HIV-1-infected children compared to controls.

Vaccination among HIV-infected, HIV-exposed uninfected and HIV-uninfected children: a systematic review and meta-analysis of evidence related to vaccine efficacy and effectiveness

Evidence-based approaches were used in making recommendations for vaccination against vaccine-preventable diseases for HIV-infected and HIV-exposed individuals but with limited substantiation. We conducted a systematic review and meta-analysis with randomized-controlled trials (RCTs), cohort and case-control studies that have efficacy and effectiveness of vaccines in HIV-infected and HIV-exposed children as outcomes. Web of Science, Cochrane Library, PubMed and Scopus databases were searched for articles. Efficacy of 9-valent pneumococcal conjugate vaccine (PCV9) against total vaccine serotype invasive pneumococcal disease was 32% in HIV-infected children and 78% among HIV-uninfected children. Vaccine effectiveness of Bacillus Calmette-Guérin vaccine in preventing tuberculosis in HIV-infected children was zero compared to 59% protection in HIV-unexposed children. Likewise, HIV-uninfected children have better protection against invasive Haemophilus influenzae type b disease than the HIV-infected children. Effectiveness studies of rotavirus vaccines show that HIV-exposed uninfected children have similar protection against rotavirus gastroenteritis compared to the non-exposed children. Children who are severely immunosuppressed are poorly protected against invasive pneumococcal diseases. HIV-infected children tend to have lesser vaccine protection against vaccine-preventable diseases when compared to unexposed children. HIV-infected children who are immunocompetent are more likely to have better vaccine protection against vaccine-preventable diseases than those who are immunosuppressed. The overall quality of the observational studies was very low with very little confidence in the effect estimate. The overall quality of evidence for the RCT outcomes was mainly high. This study reveals a dearth of efficacy and effectiveness studies among HIV-infected and exposed children.

Cost-effectiveness of PCV13 vaccination in Belgian adults aged 65-84 years at elevated risk of pneumococcal infection

Background

The Belgian Superior Health Council (SHC) recently added a 13-valent pneumococcal conjugate vaccine (PCV13) to its recommendations for adult pneumococcal vaccination. This study addresses the policy question regarding whether a single dose of PCV13 should be reimbursed among Belgian adults aged 65–84 years with chronic comorbidities (“moderate-risk”) or immunosuppression (“high-risk”).

Methods

A cohort model was developed to project lifetime risks, consequences, and costs of invasive pneumococcal disease (IPD) and pneumococcal community-acquired pneumonia (CAP). Parameter values were estimated using published literature and available databases, and were reviewed by Belgian experts. PCV13 effectiveness was assumed to be durable during the first 5 years following receipt, and to progressively decline thereafter with 15 years protection. The Belgian National Health Insurance perspective was employed.

Results

Use of PCV13 (vs. no vaccine) in moderate/high-risk persons aged 65–84 years (n = 861,467; 58% vaccination coverage) would be expected to prevent 527 cases of IPD, 1,744 cases of pneumococcal CAP and 176 pneumococcal-related deaths, and reduce medical care costs by €20.1 million. Vaccination costs, however, would increase by €36.9 million and thus total overall costs would increase by €16.8 million. Cost per QALY gained was €17,126. In probabilistic sensitivity analyses, use of PCV13 was cost-effective in 97% of 1,000 simulations.

Conclusions

Reimbursement of PCV13 in moderate/high-risk Belgian adults aged 65–84 years would be cost-effective from the Belgian healthcare perspective.