Pneumococcal Carriage Duration

Respiratory samples will be tested to determine whether Streptococcus pneumoniae (pneumococcus) is present using standard laboratory methods and genetic testing. If found, the bacteria will be genetically analyzed to identify its type (serotype) and compare it with other strains. Researchers will measure when a child first becomes colonized, when the bacteria are cleared (after two negative tests), how long colonization lasts, and how quickly new colonization occurs. Genetic analysis will determine whether the same strain persists or a new strain is acquired.

Respiratory samples will be tested to determine whether Streptococcus pneumoniae (pneumococcus) is present with other pneumococcal intra-subject lineages (ISL) using standard laboratory methods and genetic testing. If found, the bacteria will be genetically analyzed to identify the different types (serotype) and how many there are.

Respiratory samples will be tested for common viruses and bacteria using advanced laboratory methods. Researchers will also record whether participants have symptoms or are carrying these bacteria without feeling sick. They will track when a participant first acquires a new respiratory virus (one that was not detected at the previous visit) and calculate how often new infections occur over time, including comparisons by age group.

Researchers will compare different laboratory methods ( to see how well they detect Streptococcus pneumoniae and identify its type. They will also evaluate whether collecting samples every two weeks or once a month provides better information on bacterial carriage, new infections, and missing data. The study will compare different methods for analyzing the respiratory microbiome (the community of bacteria in the airways) and use computer models to determine whether microbiome patterns can predict pneumococcal carriage. Finally, researchers will compare the costs and practicality of different sampling schedules, collection methods, and laboratory tests to help guide future studies.

The PI will identify the carriage of vaccine serotypes (VT) included in the most recent PCV administered to each participant. This analysis will compare VT versus NVT carriage prevalence, stratified by age group, vaccine, and time since vaccination.