Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK

Evaristar Kudowa; Godwin Tembo; Anthony E. Chirwa; Tarsizio Chikaonda; Alfred Muyaya; Lumbani Makhaza; Edna Nsomba; Bridgette Galafa; Faith Thole; John Ndaferankhande; Lorensio Chimgoneko; Neema Toto; Dingase Dula; Ben Morton; Shaun Pennington; Angela D. Hyder-Wright; Andrea Collins; Elena Mitsi; Daniela Ferreira; Stephen Gordon; Marc Henrion

doi:10.1038/s41541-026-01381-4

Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK

Evaristar Kudowa
, Godwin Tembo
, Anthony E. Chirwa
, Tarsizio Chikaonda
, Alfred Muyaya
, Lumbani Makhaza
, Edna Nsomba
, Bridgette Galafa
, Faith Thole
, John Ndaferankhande
, Lorensio Chimgoneko
, Neema Toto
, Dingase Dula
, Ben Morton
, Shaun Pennington
, Angela D. Hyder-Wright
, Andrea Collins
, Elena Mitsi
, Daniela Ferreira
, Stephen Gordon

Marc Henrion

Malawi-Liverpool-Wellcome Trust Clinical Research Programme
Malawi-Liverpool-Welcome Programme
University of Malawi
Queen Elizabeth Central Hospital Malawi
Kamuzu Central Hospital
Maternal and Fetal Health Group
Kamuzu University of Health Sciences
Liverpool School of Tropical Medicine
Liverpool University Hospitals NHS Foundation Trust
University of Oxford
NIHR Oxford Biomedical Research Centre
Liverpool University Hospitals Foundation NHS Trust (member of Liverpool Health Partners)
UK Health Security Agency

Research output: Contribution to journal › Article › peer-review

Abstract

We conducted the first pooled analysis of two randomized controlled vaccine trials on experimental pneumococcal serotype 6B carriage, registered in Malawi
(PACTR202008503507113) and the UK (ISRCTN45340436). This post-hoc exploratory study examined the sex-based differences in carriage, vaccine efficacy and vaccine-induced responses. PCV-13 reduced colonisation by 76% (p<0.001) with non-significant interaction by sex (RR=1.549, p=0.413). Females showed a higher carriage rate than males (28% vs. 19%, p=0.066). Baseline anti-6B Capsular Polysaccharide Immunoglobulin G (IgG) titres were higher in females, significantly in Malawi (2.62 μg/ml vs males 2.05 μg/ml, p=0.015). Post-vaccination titres did not differ by sex. The pooled fold change in IgG pre-post vaccination, was higher in vaccinated females (5.47 vs 3.30, p=0.053). This analysis demonstrates the utility and challenges of integrating CHIM data between diverse settings to evaluate vaccine efficacy, describe intersetting differences, investigate biological and immunological factors influencing protection against pneumococcal carriage and ultimately inform future vaccine development strategies.

Original language	English
Article number	101
Journal	npj Vaccines
Volume	11
Issue number	1
Early online date	26 Feb 2026
DOIs	https://doi.org/10.1038/s41541-026-01381-4
Publication status	E-pub ahead of print - 26 Feb 2026

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

Themes

Innovation to Impact: Therapeutics, Diagnostics, Vaccines

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10.1038/s41541-026-01381-4Licence: CC BY

Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UKAccepted author manuscript, 1.1 MBLicence: CC BY

Cite this

Kudowa, E., Tembo, G., Chirwa, A. E., Chikaonda, T., Muyaya, A., Makhaza, L., Nsomba, E., Galafa, B., Thole, F., Ndaferankhande, J., Chimgoneko, L., Toto, N., Dula, D., Morton, B., Pennington, S., Hyder-Wright, A. D., Collins, A., Mitsi, E., Ferreira, D., ... Henrion, M. (2026). Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK. npj Vaccines, 11(1), Article 101. Advance online publication. https://doi.org/10.1038/s41541-026-01381-4

@article{b37d16c42fa54431ac3238caacecc9e4,

title = "Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK",

abstract = "We conducted the first pooled analysis of two randomized controlled vaccine trials on experimental pneumococcal serotype 6B carriage, registered in Malawi (PACTR202008503507113) and the UK (ISRCTN45340436). This post-hoc exploratory study examined the sex-based differences in carriage, vaccine efficacy and vaccine-induced responses. PCV-13 reduced colonisation by 76\% (p<0.001) with non-significant interaction by sex (RR=1.549, p=0.413). Females showed a higher carriage rate than males (28\% vs. 19\%, p=0.066). Baseline anti-6B Capsular Polysaccharide Immunoglobulin G (IgG) titres were higher in females, significantly in Malawi (2.62 μg/ml vs males 2.05 μg/ml, p=0.015). Post-vaccination titres did not differ by sex. The pooled fold change in IgG pre-post vaccination, was higher in vaccinated females (5.47 vs 3.30, p=0.053). This analysis demonstrates the utility and challenges of integrating CHIM data between diverse settings to evaluate vaccine efficacy, describe intersetting differences, investigate biological and immunological factors influencing protection against pneumococcal carriage and ultimately inform future vaccine development strategies.",

author = "Evaristar Kudowa and Godwin Tembo and Chirwa, \{Anthony E.\} and Tarsizio Chikaonda and Alfred Muyaya and Lumbani Makhaza and Edna Nsomba and Bridgette Galafa and Faith Thole and John Ndaferankhande and Lorensio Chimgoneko and Neema Toto and Dingase Dula and Ben Morton and Shaun Pennington and Hyder-Wright, \{Angela D.\} and Andrea Collins and Elena Mitsi and Daniela Ferreira and Stephen Gordon and Marc Henrion",

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month = feb,

day = "26",

doi = "10.1038/s41541-026-01381-4",

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Kudowa, E, Tembo, G, Chirwa, AE, Chikaonda, T, Muyaya, A, Makhaza, L, Nsomba, E, Galafa, B, Thole, F, Ndaferankhande, J, Chimgoneko, L, Toto, N, Dula, D, Morton, B , Pennington, S, Hyder-Wright, AD, Collins, A, Mitsi, E, Ferreira, D, Gordon, S & Henrion, M 2026, 'Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK', npj Vaccines, vol. 11, no. 1, 101. https://doi.org/10.1038/s41541-026-01381-4

TY - JOUR

T1 - Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK

AU - Kudowa, Evaristar

AU - Tembo, Godwin

AU - Chirwa, Anthony E.

AU - Chikaonda, Tarsizio

AU - Muyaya, Alfred

AU - Makhaza, Lumbani

AU - Nsomba, Edna

AU - Galafa, Bridgette

AU - Thole, Faith

AU - Ndaferankhande, John

AU - Chimgoneko, Lorensio

AU - Toto, Neema

AU - Dula, Dingase

AU - Morton, Ben

AU - Pennington, Shaun

AU - Hyder-Wright, Angela D.

AU - Collins, Andrea

AU - Mitsi, Elena

AU - Ferreira, Daniela

AU - Gordon, Stephen

AU - Henrion, Marc

PY - 2026/2/26

Y1 - 2026/2/26

N2 - We conducted the first pooled analysis of two randomized controlled vaccine trials on experimental pneumococcal serotype 6B carriage, registered in Malawi (PACTR202008503507113) and the UK (ISRCTN45340436). This post-hoc exploratory study examined the sex-based differences in carriage, vaccine efficacy and vaccine-induced responses. PCV-13 reduced colonisation by 76% (p<0.001) with non-significant interaction by sex (RR=1.549, p=0.413). Females showed a higher carriage rate than males (28% vs. 19%, p=0.066). Baseline anti-6B Capsular Polysaccharide Immunoglobulin G (IgG) titres were higher in females, significantly in Malawi (2.62 μg/ml vs males 2.05 μg/ml, p=0.015). Post-vaccination titres did not differ by sex. The pooled fold change in IgG pre-post vaccination, was higher in vaccinated females (5.47 vs 3.30, p=0.053). This analysis demonstrates the utility and challenges of integrating CHIM data between diverse settings to evaluate vaccine efficacy, describe intersetting differences, investigate biological and immunological factors influencing protection against pneumococcal carriage and ultimately inform future vaccine development strategies.

AB - We conducted the first pooled analysis of two randomized controlled vaccine trials on experimental pneumococcal serotype 6B carriage, registered in Malawi (PACTR202008503507113) and the UK (ISRCTN45340436). This post-hoc exploratory study examined the sex-based differences in carriage, vaccine efficacy and vaccine-induced responses. PCV-13 reduced colonisation by 76% (p<0.001) with non-significant interaction by sex (RR=1.549, p=0.413). Females showed a higher carriage rate than males (28% vs. 19%, p=0.066). Baseline anti-6B Capsular Polysaccharide Immunoglobulin G (IgG) titres were higher in females, significantly in Malawi (2.62 μg/ml vs males 2.05 μg/ml, p=0.015). Post-vaccination titres did not differ by sex. The pooled fold change in IgG pre-post vaccination, was higher in vaccinated females (5.47 vs 3.30, p=0.053). This analysis demonstrates the utility and challenges of integrating CHIM data between diverse settings to evaluate vaccine efficacy, describe intersetting differences, investigate biological and immunological factors influencing protection against pneumococcal carriage and ultimately inform future vaccine development strategies.

U2 - 10.1038/s41541-026-01381-4

DO - 10.1038/s41541-026-01381-4

M3 - Article

SN - 2059-0105

VL - 11

JO - npj Vaccines

JF - npj Vaccines

IS - 1

M1 - 101

ER -

Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK

Abstract

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