Understanding Pneumococcal Carriage and Disease 2017-2020

This is a cross sectional observational study to determine the point prevalence of pneumococcal carriage in children. In this study up to 1600, healthy children aged 13-48 months who have received a complete course of PCV13 at least one month prior to study enrolment, will be recruited. In addition, up to 800, 6-12 month old children who have received a priming dose of PCV13 will be recruited. For the 13-48 month cohort, an interim analysis for futility to demonstrate an increase in serotype 19A will be performed after the first 750 participants. The study will be carried out in the Thames Valley and South Midlands. Parents/legal guardians will be approached either by website based advertisements, social media, poster advertisements and emailing and/or handing out information booklets through their child's nurseries, GP Surgeries and educational/play settings. The investigators may also identify potential participants by mailing out invitation letters and leaflets to age appropriate children via the Open Exeter system of National Health Application and Infrastructure Services, the Child Health Computer Department, equivalent NHS database or through the Clinical Research Network. Parents/legal guardians of potential participants who have expressed interest will be directed to the Oxford Vaccine group (OVG) website where they will be able to access the participant information booklet and if appropriate complete online self-screening. If parents approach OVG to express interest, the information booklet will be sent to them and they may be telephone screened. This study will involve a one off visit. The study visit will be arranged to occur in a convenient venues such as: hospital out patients, university clinic rooms, village halls, church halls, nurseries, participant's homes, sporting and recreational areas, GP practices and other similar venues where pre-school children frequently attend. Permission would be seek from the above venues to carry out any study procedures on their premises. Pre-arranged dates and times will be offered to parents/legal guardians by online booking, phone call or email. During the visit the investigators would go through the details of the study and provide an opportunity for further questions. For those willing to proceed the investigators would then ask participants to sign a consent form and collect demographic information. A nasopharyngeal swab will be taken, and if consented to do so an optional blood sample will be performed in a subset of 632 participants. No further visits or follow-up will be required.