TY - JOUR
T1 - High residual carriage of vaccine-serotype Streptococcus pneumoniae after introduction of pneumococcal conjugate vaccine in Malawi
AU - Swarthout, Todd D.
AU - Fronterre, Claudio
AU - Lourenço, José
AU - Obolski, Uri
AU - Gori, Andrea
AU - Bar-Zeev, Naor
AU - Everett, Dean
AU - Kamng’ona, Arox W.
AU - Mwalukomo, Thandie S.
AU - Mataya, Andrew A.
AU - Mwansambo, Charles
AU - Banda, Marjory
AU - Gupta, Sunetra
AU - Diggle, Peter
AU - French, Neil
AU - Heyderman, Robert S.
N1 - Funding Information:
We thank the individuals who participated in this study and the local schools and authorities for their support. We are grateful to the study field teams (supported by Farouck Bonomali and Roseline Nyirenda) and the study laboratory team. We are grateful to the hospitality of the QECH ART Clinic, led by Ken Malisita. Our thanks also extend to the MLW laboratory management team (led by Brigitte Denis) and the MLW data management team (led by Clemens Masesa). R.S.H., N.F., and T.S. are supported by the National Institute for Health Research (NIHR) Global Health Research Unit on Mucosal Pathogens using UK aid from the UK Government. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
Funding Information:
T.D.S., N.B-Z., D.E., N.F., and R.S.H. designed the study. T.D.S, C.F., J.L., U.O., A.G., N.B-Z., D.E., A.W.K., T.S.M., A.A.M., C.M., M.B., S.G., P.D., N.F., and R.S.H. contributed to the development or design of methodology. T.D.S., N.F. and R.H.S. oversaw the study, data collection, and data management. C.F. and P.D. developed the statistical regression analysis. T.D.S., N.B-Z, N.F., and R.S.H. conducted the statistical analysis. T.D.S., N.F., and R.S.H. wrote the first draft of the paper. T.D.S., C.F., J.L., U.O., A.G., N.B-Z., D.E., A.W.K., T.S.M., A.A.M., C.M., M.B., S.G., P.D., N.F., and R.S.H. contributed to subsequent drafts and read and approved the final version of the report. Bill & Melinda Gates Foundation, USA. A project grant jointly funded by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement, also as part of the EDCTP2 programme supported by the European Union (MR/N023129/1); and a recruitment award from the Wellcome Trust (Grant 106846/Z/15/Z). The MLW Clinical Research Programme is supported by a Strategic Award from the Wellcome Trust, UK. National Institute for Health Research (NIHR) Global Health Research Unit on Mucosal Pathogens using UK aid from the UK Government. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. The funders had no role in study design, collection, analysis, data interpretation, writing of the report or in the decision to submit the paper for publication. The corresponding author had full access to the study data and, together with the senior authors, had final responsibility for the decision to submit for publication.
Funding Information:
N.B-Z. reports investigator-initiated research grants from GlaxoSmithKline Biologicals and from Takeda Pharmaceuticals outside the submitted work. No other authors declare competing interests.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - There are concerns that pneumococcal conjugate vaccines (PCVs) in sub-Saharan Africa sub-optimally interrupt Streptococcus pneumoniae vaccine-serotype (VT) carriage and transmission. Here we assess PCV carriage using rolling, prospective nasopharyngeal carriage surveys between 2015 and 2018, 3.6–7.1 years after Malawi’s 2011 PCV13 introduction. Carriage decay rate is analysed using non-linear regression. Despite evidence of reduction in VT carriage over the study period, there is high persistent residual carriage. This includes among PCV-vaccinated children 3–5-year-old (16.1% relative reduction from 19.9% to 16.7%); PCV-unvaccinated children 6–8-year-old (40.5% reduction from 26.4% to 15.7%); HIV-infected adults 18-40-years-old on antiretroviral therapy (41.4% reduction from 15.2% to 8.9%). VT carriage prevalence half-life is similar among PCV-vaccinated and PCV-unvaccinated children (3.26 and 3.34 years, respectively). Compared with high-income settings, there is high residual VT carriage 3.6–7.1 years after PCV introduction. Rigorous evaluation of strategies to augment vaccine-induced control of carriage, including alternative schedules and catch-up campaigns, is required.
AB - There are concerns that pneumococcal conjugate vaccines (PCVs) in sub-Saharan Africa sub-optimally interrupt Streptococcus pneumoniae vaccine-serotype (VT) carriage and transmission. Here we assess PCV carriage using rolling, prospective nasopharyngeal carriage surveys between 2015 and 2018, 3.6–7.1 years after Malawi’s 2011 PCV13 introduction. Carriage decay rate is analysed using non-linear regression. Despite evidence of reduction in VT carriage over the study period, there is high persistent residual carriage. This includes among PCV-vaccinated children 3–5-year-old (16.1% relative reduction from 19.9% to 16.7%); PCV-unvaccinated children 6–8-year-old (40.5% reduction from 26.4% to 15.7%); HIV-infected adults 18-40-years-old on antiretroviral therapy (41.4% reduction from 15.2% to 8.9%). VT carriage prevalence half-life is similar among PCV-vaccinated and PCV-unvaccinated children (3.26 and 3.34 years, respectively). Compared with high-income settings, there is high residual VT carriage 3.6–7.1 years after PCV introduction. Rigorous evaluation of strategies to augment vaccine-induced control of carriage, including alternative schedules and catch-up campaigns, is required.
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U2 - 10.1038/s41467-020-15786-9
DO - 10.1038/s41467-020-15786-9
M3 - Article
C2 - 32376860
AN - SCOPUS:85084327233
VL - 11
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 2222
ER -