Shabir A Madhi1,2, Susan A Nzenze1,2, Marta C Nunes1,2, Lilian Chinyanganya1,2, Nadia Van Niekerk1,2, Kathleen Kahn3,4,5, Rhine Twine3, Linda De Gouveia6, Anne Von Gottberg6, Tinevimbo Shiri1,2,7. 1. Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand , Johannesburg, South Africa. 2. Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg, South Africa. 3. MRC/Wits Rural Public Health and Health Transitions Research Unit, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand , Johannesburg, South Africa. 4. Centre for Global Health Research, Umeå University , Umeå, Sweden. 5. INDEPTH Network , Accra, Ghana. 6. Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, National Health Laboratory Service , Johannesburg, South Africa. 7. Liverpool School of Tropical Medicine , Liverpool, UK.
Abstract
BACKGROUND: We evaluated pneumococcal colonization in children and adults between the time of 7-valent pneumococcal conjugate vaccine (PCV) introduction in the immunization program in 2009 to two years after transitioning to PCV13 in 2011. METHODS: Community-based carriage surveillance was undertaken between May-November 2013 (Period-3), with similar surveys in 2009 (Period-1) and 2011 (Period-2). Households with children below two years had a similar probability of being sampled in all surveys. Nasopharyngeal swabs were processed using standard methods and serotyped by Quellung. RESULTS: In children>9-59 months old, overall pneumococcal colonization prevalence declined from 81.8% in Period-1 to 65.0% in Period-3 (p<0.001). Reductions of 70% (41.2% vs. 13.6%) in PCV7-serotypes colonization and 66% (15.3% vs. 4.4%) for the six additional PCV13-serotypes (PCV13-add6VT) were observed. There was, however, high residual colonization by PCV7-serotypes 19F (14.9% vs. 6.3%) and 23F (8.5% vs. 4.1%), despite reduction of 57% and 52%, respectively. Among individuals>12 years of age, there was 61% reduction in PCV7-serotype colonization (3.1% vs. 1.3%) and 75% decrease for PCV13-add6VT (2.1% vs. 0.6%) between Period-1 and Period-3. CONCLUSIONS: The residual prevalence of serotypes 19F and 23F, four years after introducing PCV in the South Africa, suggests ongoing community transmission and transient vaccine effects.
BACKGROUND: We evaluated pneumococcal colonization in children and adults between the time of 7-valent pneumococcal conjugate vaccine (PCV) introduction in the immunization program in 2009 to two years after transitioning to PCV13 in 2011. METHODS: Community-based carriage surveillance was undertaken between May-November 2013 (Period-3), with similar surveys in 2009 (Period-1) and 2011 (Period-2). Households with children below two years had a similar probability of being sampled in all surveys. Nasopharyngeal swabs were processed using standard methods and serotyped by Quellung. RESULTS: In children>9-59 months old, overall pneumococcal colonization prevalence declined from 81.8% in Period-1 to 65.0% in Period-3 (p<0.001). Reductions of 70% (41.2% vs. 13.6%) in PCV7-serotypes colonization and 66% (15.3% vs. 4.4%) for the six additional PCV13-serotypes (PCV13-add6VT) were observed. There was, however, high residual colonization by PCV7-serotypes 19F (14.9% vs. 6.3%) and 23F (8.5% vs. 4.1%), despite reduction of 57% and 52%, respectively. Among individuals>12 years of age, there was 61% reduction in PCV7-serotype colonization (3.1% vs. 1.3%) and 75% decrease for PCV13-add6VT (2.1% vs. 0.6%) between Period-1 and Period-3. CONCLUSIONS: The residual prevalence of serotypes 19F and 23F, four years after introducing PCV in the South Africa, suggests ongoing community transmission and transient vaccine effects.
Authors: Akuzike Kalizang'oma; Chrispin Chaguza; Andrea Gori; Charlotte Davison; Sandra Beleza; Martin Antonio; Bernard Beall; David Goldblatt; Brenda Kwambana-Adams; Stephen D Bentley; Robert S Heyderman Journal: Microb Genom Date: 2021-09
Authors: Nida Javaid; Courtney Olwagen; Susan Nzenze; Paulina Hawkins; Rebecca Gladstone; Lesley McGee; Robert F Breiman; Stephen D Bentley; Shabir A Madhi; Stephanie Lo Journal: Microb Genom Date: 2022-06