RSV and rhinovirus increase pneumococcal carriage acquisition and density, whereas nasal inflammation is associated with bacterial shedding.

Epidemiological studies report the impact of co-infection with pneumococcus and respiratory viruses upon disease rates and outcomes, but their effect on pneumococcal carriage acquisition and bacterial load is scarcely described. Here, we assess this by combining natural viral infection with controlled human pneumococcal infection in 581 healthy adults screened for upper respiratory tract viral infection before intranasal pneumococcal challenge. Across all adults, respiratory syncytial virus (RSV) and rhinovirus asymptomatic infection confer a substantial increase in secondary infection with pneumococcus.

Demonstration of immunologic memory using serogroup C meningococcal glycoconjugate vaccine.

Background: Studies of glycoconjugate vaccines have traditionally used an immune challenge with a plain polysaccharide vaccine to demonstrate immunologic memory. Plain polysaccharide vaccines are poorly immunogenic in children and can induce subsequent immunologic hyporesponsiveness. We therefore assessed the use of glycoconjugate vaccines as an alternative method of demonstrating immunologic memory.

Haemophilus influenzae type b vaccine failure in children is associated with inadequate production of high-quality antibody.

Background: Despite the excellent immunogenicity of Haemophilus influenzae type b (Hib) conjugate vaccines, breakthrough cases of Hib disease still affect a small proportion of vaccinated children in the United Kingdom. We performed a retrospective study to compare the avidity of antibody directed against the Hib polysaccharide capsule (PRP) in children who experienced Hib vaccine failure in the United Kingdom among 3 historical cohorts and with age-matched healthy control subjects.

Methods: Serum samples from vaccinated children with invasive Hib disease were collected beginning in 1992 as part of enhanced surveillance for Hib disease following vaccine introduction.