{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T06:22:34Z","timestamp":1791872554449,"version":"4.3.4"},"reference-count":28,"publisher":"Oxford University Press (OUP)","issue":"12","license":[{"start":{"date-parts":[[2016,12,1]],"date-time":"2016-12-01T00:00:00Z","timestamp":1480550400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000265","name":"Medical Research Council","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000265","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000272","name":"National Institute for Health Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["105616\/Z\/14\/Z (M.A.G.)"],"award-info":[{"award-number":["105616\/Z\/14\/Z (M.A.G.)"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2016,12,15]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Rationale<\/jats:title>\n                    <jats:p>We have previously demonstrated that experimental pneumococcal carriage enhances immunity and protects healthy adults against carriage reacquisition after rechallenge with a homologous strain.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To investigate the role of naturally acquired pneumococcal protein and polysaccharide (PS)-specific immunity in protection against carriage acquisition using a heterologous challenge model.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We identified healthy volunteers that were naturally colonized with pneumococcus and, after clearance of their natural carriage episode, challenged them with a heterologous 6B strain. In another cohort of volunteers we assessed 6BPS-specific, PspA-specific, and PspC-specific IgG and IgA plasma and memory B-cell populations before and 7, 14, and 35 days after experimental pneumococcal inoculation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Measurements and Main Results<\/jats:title>\n                    <jats:p>Heterologous challenge with 6B resulted in 50% carriage among volunteers with previous natural pneumococcal carriage. Protection from carriage was associated with a high number of circulating 6BPS IgG\u2013secreting memory B cells at baseline. There were no associations between protection from carriage and baseline levels of 6BPS IgG in serum or nasal wash, PspA-specific, or PspC-specific memory B cells or plasma cells. In volunteers who did not develop carriage, the number of circulating 6BPS memory B cells decreased and the number of 6BPS plasma cells increased postinoculation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Our data indicate that naturally acquired PS-specific memory B cells, but not levels of circulating IgG at time of pneumococcal exposure, are associated with protection against carriage acquisition.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1164\/rccm.201512-2467oc","type":"journal-article","created":{"date-parts":[[2016,7,12]],"date-time":"2016-07-12T16:55:33Z","timestamp":1468342533000},"page":"1523-1531","source":"Crossref","is-referenced-by-count":68,"title":["Polysaccharide-Specific Memory B Cells Predict Protection against Experimental Human Pneumococcal Carriage"],"prefix":"10.1093","volume":"194","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7160-6275","authenticated-orcid":false,"given":"Shaun H.","family":"Pennington","sequence":"first","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"},{"name":"Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sherin","family":"Pojar","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elena","family":"Mitsi","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jenna F.","family":"Gritzfeld","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elissavet","family":"Nikolaou","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carla","family":"Sol\u00f3rzano","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jessica T.","family":"Owugha","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qasim","family":"Masood","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melita A.","family":"Gordon","sequence":"additional","affiliation":[{"name":"Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom"},{"name":"Malawi\u2013Liverpool\u2013Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi; 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