DOI: 10.25934/pr00009016
title: Evaluation of Immune Response of 10-valent Pneumococcal Conjugate Vaccine (PCV-10) in HIV infected and uninfected children

description: Streptococcus pneumoniae is a bacteria that is commonly found in the nose and throat and can infect other areas of the body (lungs, ears, brain, spinal cord and blood). When the bacteria spreads to other areas of the body, it can cause severe illness in children, the elderly and those with weakened immune systems. Pneumococcal disease refers to any infection caused by Streptococcus pneumoniae.

Streptococcus pneumoniae related infections are a major cause of morbidity and mortality worldwide causing a variety of serious illnesses. Infections due to Streptococcus pneumoniae are the leading vaccine-preventable cause of death in children. Between 0.7 – 1 million deaths among children below 5 years of age in developing countries in 2005 were attributed to pneumococcal diseases.

Vaccines to combat disease due to Streptococcus pneumoniae have been in use for over 20 years. Pneumococcal vaccines protect against several different serotypes or strains of Streptococcus pneumoniae. For example, a 10-valent pneumococcal vaccine will protect against ten different pneumococcal serotypes of Streptococcus pneumoniae. Pneumococcal conjugate vaccines are vaccines which are formed by chemically joining a protein to the pneumococcus to enhance the immune response to the vaccine.

People living with the Human Immunodeficiency virus (HIV) have a weakened immune system as HIV is a virus that damages the cells in the immune system and weakens your ability to fight everyday infections and disease. As such, children living with HIV or exposed to HIV in-utero may or may not have different immune responses to vaccines compared with HIV-uninfected and unexposed children.

The study for which we request data from (referred to as the initial study), evaluated immune responses to a pneumococcal conjugate vaccine produced by GSK Biologicals throughout the first two years of life in children living with HIV and HIV-uninfected children at varying dosing schedules.

There is limited data on the long-term durability of the 10-valent Pneumococcal Conjugate Vaccine (PCV-10) when provided as a primary series of two or three doses during early infancy and subsequent booster dose at 9 months of age. The University of Witwatersrand Vaccine and Infectious Disease Analytics research unit (previously known as Respiratory and Meningeal Pathogens Research Unit) performed an extension of the study described above to evaluate the durability of the immune response to the vaccine at 36, 48 and 60 months of age in children living with HIV and HIV-uninfected children with varying dosing schedules.

The proposed research would combine the vaccination information from the study participants in the initial study to maintain the same analysis groups when evaluating immune responses at 36, 48 and 60 months of age. This is important for consistency and comparability to the previously published results. Understanding the immune response at 36, 48 and 60 months of age in the study participants which had varying dosing schedules which will aid in the understanding of the durability of immune responses induced by vaccination. The aim of this study is to evaluate the long-term immune response to PCV-10 in children living with HIV and HIV-uninfected children.

The design of the initial study was a randomised controlled study. The extension study is an observational comprising of participants in the initial study. Participants in the extension study were observed at 36, 48 and 60 months and blood samples taken at each of these time points. These samples were then tested to evaluate the immune response for each participant. The immune responses for each group will be summarised and presented.