Understanding pneumococcal carriage and disease 2017/2018
Research type
Research Study
Full title
Cross-sectional study to establish the point prevalence of serotype 19A pneumococcal nasopharyngeal carriage of fully vaccinated children aged 13-48 months 6 years following introduction of PCV-13.
IRAS ID
223160
Contact name
Matthew Snape
Contact email
Sponsor organisation
University of Oxford
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Research Summary
Streptococcus pneumoniae is a type of bacteria that is carried (lives) in the nose of most individuals and can sometimes go on to cause severe infections such as meningitis and pneumonia. There are over 100 types of pneumococcus, and children in the UK have been routinely immunised against pneumococcal disease since 2006. A vaccine against 13 types of pneumococcus (PCV 13) was introduced into the UK in 2010, replacing a previous version that prevented 7 types.Pneumococcal carriage in the Thames Valley region has been studied over the last 7 years with carriage rates having been shown to be reflective of potential severe pneumococcal disease and hence vaccine effect.
The main purpose of this study is to see whether the pneumococcal immunisation program has changed the frequency and nature of pneumococcal bacteria carried by children, as this may give us a clue as to what changes in pneumococcal disease we are likely to see in the future. In addition, this study is especially timely given the possibility of a change in the PCV 13 immunisation schedule that is currently being assessed in the ‘Sched3’ Immunisation study (NCT02482636). Obtaining accurate baseline data will be important in informing the interpretation of any subsequent data on carriage rates obtained following introduction of the new schedule.
This study will enroll approximately 1600 children aged 13 to 48 months living in the Thames Valley and South Midlands and which have had three doses of 13-valent pneumococcal conjugate vaccine. The study consists of one visit done at a convenient venue (GP surgeries, educational/ play settings, or home) where a single nasal swab and an optional finger-prick blood sample for a sub-set of 632 participants, will be performed and compared to biobank samples. No additional follow-up is needed. The study recruitment period will be done over 12 months.
Summary of results
Monitoring changes in pharyngeal carriage of pneumococcus in children following 13-valent pneumococcal conjugate vaccine (PCV13) introduction in the UK in 2010 informs understanding of patterns of invasive pneumococcal disease (IPD) incidence.
Nasopharyngeal swabs from healthy children vaccinated with PCV13 according to schedule (2, 4, 12 months) were cultured and serotyped. Results for children aged 13-48 months were compared between 2014/15 and 2017/19, and with children aged 6-12 months (2017/20). Blood was obtained from a subset of children for pneumococcal serotype-specific IgG.
Total pneumococcal carriage at 13-48 months was 47.9% (473/988) in 2014/15 and 51.8% (412/795) in 2017/19 (p=0.10); at age 6-12 months this value was 44.6% (274/615). In 2017/19, 2.9% (95% CI 1.8-4.3%) of children aged 13-48 months carried PCV13 serotypes (mainly 3 (1.5%) and 19A (0.8%)) and over 20% carried the additional PCV20 serotypes. Similar proportions of children had IgG ≥0.35 IU/mL for each serotype in 2014/15 and 2017/19.
Serotype 7C carriage increased significantly (p<0.01) between 2014/15 and 2017/19. Carriage of PCV20 serotypes 8 and 12F, both major causes of IPD, was rare.
Introduction of PCV20, if licensed for children, could significantly change the composition of pneumococcal serotypes carried in the pharynx of UK children.REC name
East Midlands - Nottingham 2 Research Ethics Committee
REC reference
17/EM/0158
Date of REC Opinion
5 May 2017
REC opinion
Further Information Favourable Opinion