A Study to Assess the Carriage of Pneumococci in Children Aged 1-5 Years, and Their Household Contacts

Pneumococci are bacteria which can cause serious and potentially life threatening illnesses like meningitis and blood poisoning. There are ~90 strains, some are more dangerous than others in the severity of the disease they cause. Around half of all children carry pneumococci at the back of their nose without any ill effect. Pneumococcal vaccines (PCV) have been given in the national immunisation schedule since 2006. Vaccines protect individuals by making antibodies to be made in the blood and these vaccines help to clear the pneumococci from the nose, which helps control disease in the population by stopping their onward transmission when children cough and sneeze. This clearing effect is specific to the strains that are included in the vaccine. The first vaccines used included seven (PCV7) strains and the one used currently includes 13 (PCV13).

This group has conducted three previous carriage studies, and this will be the fourth. The first was before any vaccine was used, the second just after PCV7 was introduced and the third after the UK moved to using PCV13. These carriage studies allow assessment of how the strains in the nose change over time, in that by clearing some strains away which other strains take up those niches in their place both in children and in their close/household contacts. This helps to inform the best use of the vaccines available and for future vaccine development and which strains would be useful to include.

All families registered at participating surgeries, with a child aged 1-5 years, will be invited to take part. The study involves a single nasopharyngeal swab and a saliva swab from the child and as many other household members as are happy to participate. Participants may be seen at their GP surgery or in the home if more mutually convenient