IMMUNOGENICITY AND IMPACT ON NASOPHARYNGEAL CARRIAGE OF A SINGLE DOSE OF PCV10 GIVEN TO VIETNAMESE CHILDREN AT 18 MONTHS OF AGE

Rachel A Higgins; Beth Temple; Vo Thi Trang Dai; Thanh V Phan; Nguyen Trong Toan; Leena Spry; Zheng Quan Toh; Monica L Nation; Belinda D Ortika; Doan Y Uyen; Yin Bun Cheung; Cattram D Nguyen; Kathryn Bright; Jason Hinds; Anne Balloch; Heidi Smith-Vaughan; Tran Ngoc Huu; Kim Mulholland; Catherine Satzke; Paul V Licciardi

doi:10.1016/j.lanwpc.2021.100273

IMMUNOGENICITY AND IMPACT ON NASOPHARYNGEAL CARRIAGE OF A SINGLE DOSE OF PCV10 GIVEN TO VIETNAMESE CHILDREN AT 18 MONTHS OF AGE

Lancet Reg Health West Pac. 2021 Sep 20:16:100273. doi: 10.1016/j.lanwpc.2021.100273. eCollection 2021 Nov.

Authors

Rachel A Higgins¹, Beth Temple^{1

2

3}, Vo Thi Trang Dai⁴, Thanh V Phan⁴, Nguyen Trong Toan⁵, Leena Spry¹, Zheng Quan Toh^{1

6}, Monica L Nation¹, Belinda D Ortika¹, Doan Y Uyen⁵, Yin Bun Cheung^{7

8}, Cattram D Nguyen^{1

6}, Kathryn Bright¹, Jason Hinds^{9

10}, Anne Balloch¹, Heidi Smith-Vaughan², Tran Ngoc Huu⁵, Kim Mulholland^{1

6

3}, Catherine Satzke^{1

6

11}, Paul V Licciardi^{1

6}

Affiliations

¹ Infection and Immunity, Murdoch Children's Research Institute, Melbourne, Australia.
² Global Health, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
³ Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
⁴ Microbiology and Immunology, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam.
⁵ Department of Disease Control and Prevention, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam.
⁶ Department of Paediatrics, The University of Melbourne, Melbourne, Australia.
⁷ Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.
⁸ Centre for Child Health Research, University of Tampere and Tampere University Hospital, Tampere, Finland.
⁹ Institute for Infection and Immunity, St George's, University of London, London, UK.
¹⁰ BUGS Bioscience, London Bioscience Innovation Centre, London, UK.
¹¹ Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Australia.

Abstract

Background: This study investigated the immunogenicity and impact on nasopharyngeal carriage of a single dose of PCV10 given to 18-month-old Vietnamese children. This information is important for countries considering catch-up vaccination during PCV introduction and in the context of vaccination during humanitarian crises.

Methods: Two groups of PCV-naïve children within the Vietnam Pneumococcal Project received PCV10 (n=197) or no PCV (unvaccinated; n=199) at 18 months of age. Blood samples were collected at 18, 19, and 24 months of age, and nasopharyngeal swabs at 18 and 24 months of age. Immunogenicity was assessed by measuring serotype-specific IgG, opsonophagocytosis (OPA) and memory B cells (Bmem). Pneumococci were detected and quantified using real-time PCR and serotyped by microarray.

Findings: At 19 months of age, IgG and OPA responses were higher in the PCV10 group compared with the unvaccinated group for all PCV10 serotypes and cross-reactive serotypes 6A and 19A. This was sustained out to 24 months of age, at which point PCV10-type carriage was 60% lower in the PCV10 group than the unvaccinated group. Bmem levels increased between 18 and 24 months of age in the vaccinated group.

Interpretation: We demonstrate strong protective immune responses in vaccinees following a single dose of PCV10 at 18 months of age, and a potential impact on herd protection through a substantial reduction in vaccine-type carriage. A single dose of PCV10 in the second year of life could be considered as part of catch-up campaigns or in humanitarian crises to protect children at high-risk of pneumococcal disease.