Protective effect of PCV vaccine against experimental pneumococcal challenge in adults is primarily mediated by controlling colonisation density



German, EL, Solorzano, C, Sunny, S, Dunne, F, Gritzfeld, JF, Mitsi, E, Nikolaou, E, Hyder-Wright, AD, Collins, AM, Gordon, SB
et al (show 1 more authors) (2019) Protective effect of PCV vaccine against experimental pneumococcal challenge in adults is primarily mediated by controlling colonisation density. VACCINE, 37 (30). pp. 3953-3956.

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Abstract

Widespread use of Pneumococcal Conjugate Vaccines (PCV) has reduced vaccine-type nasopharyngeal colonisation and invasive pneumococcal disease. In a double-blind, randomised controlled trial using the Experimental Human Pneumococcal Challenge (EHPC) model, PCV-13 (Prevenar-13) conferred 78% protection against colonisation acquisition and reduced bacterial intensity (AUC) as measured by classical culture. We used a multiplex qPCR assay targeting lytA and pneumococcal serotype 6A/B cpsA genes to re-assess the colonisation status of the same volunteers. Increase in detection of low-density colonisation resulted in reduced PCV efficacy against colonisation acquisition (29%), compared to classical culture (83%). For experimentally colonised volunteers, PCV had a pronounced effect on decreasing colonisation density. These results obtained in adults suggest that the success of PCV vaccination could primarily be mediated by the control of colonisation density. Studies assessing the impact of pneumococcal vaccines should allow for density measurements in their design.

Item Type: Article
Uncontrolled Keywords: Pneumococcus, PCV, Colonisation, Density, QPCR
Depositing User: Symplectic Admin
Date Deposited: 08 Aug 2019 10:41
Last Modified: 19 Jan 2023 00:35
DOI: 10.1016/j.vaccine.2019.05.080
Open Access URL: https://doi.org/10.1016/j.vaccine.2019.05.080
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3051283