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Residual colonization by vaccine serotypes in rural South Africa four years following initiation of pneumococcal conjugate vaccine immunization

Madhi, Shabir A, Nzenze, Susan A, Nunes, Marta C, Chinyanganya, Lilian, van Niekerk, Nadia, Kahn, Kathleen, Twine, Rhine, de Gouveia, Linda, von Gottberg, Anne and Shiri, Tinevimbo ORCID: (2020) 'Residual colonization by vaccine serotypes in rural South Africa four years following initiation of pneumococcal conjugate vaccine immunization'. Expert Review of Vaccines, Vol 19, Issue 4, pp. 383-393.

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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 April 2009 to two years after transitioning to 13-valent PCV in 2011.
Methods: Community-based pneumococcal carriage surveillance was undertaken between May-November 2013 (Period-3; n=1884), with similar surveys in 2009 (Period-1, n=2010) and 2011 (Period-2; n=3659). 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 of age, overall pneumococcal colonization prevalence declined from 81.8% in Period-1 to 65.0% in Period-3 (p<0.001). Reductions of 70% (95%CI: 60%-77%; 41.2% vs. 13.6%) in PCV7-serotypes colonization and 66% (95%CI:48%-78%; 15.3% vs. 4.4%) for the six additional PCV-serotypes in PCV13 (PCV13
add6VT) were observed. There was, however, high residual prevalence of colonization by PCV7-serotypes 19F (14.9% vs. 6.3%) and 23F (8.5% vs. 4.1%), despite reduction of 57% (95%CI:35%-80%) and 52% (95%CI:21%-83%), respectively. Among individuals >12 years
of age, there was 61% (95%CI:18%-82%) reduction in PCV7-serotype colonization (3.1% vs. 1.3%; ) and 75% (95%CI: 11%-93%) decrease for PCV13-add6VT (2.1% vs. 0.6%) between Period-1 and Period-3.
Conclusions: The residual prevalence of serotypes 19F and 23F in PCV-immunized and unvaccinated age-groups, four years after introducing PCV in the South African public immunization program, suggests ongoing community transmission and transient vaccine

Item Type: Article
Subjects: WA Public Health > Preventive Medicine > WA 115 Immunization
WA Public Health > Health Problems of Special Population Groups > WA 395 Health in developing countries
WC Communicable Diseases > Infection. Bacterial Infections > Bacterial Infections > WC 217 Pneumococcal infections
Faculty: Department: Clinical Sciences & International Health > International Public Health Department
Digital Object Identifer (DOI):
Depositing User: Stacy Murtagh
Date Deposited: 21 Apr 2020 10:48
Last Modified: 10 Apr 2021 01:02


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