Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial

<br><strong>Background<br></strong> Typhoid fever is a major public health problem in low-resource settings. Vaccination can help curb the disease and might reduce transmission. We have previously reported an interim analysis of the efficacy of typhoid conjugate vaccine (TCV)...

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Main Authors: Shakya, M, Voysey, M, Theiss-Nyland, K, Colin-Jones, R, Pant, D, Adhikari, A, Tonks, S, Mujadidi, YF, O'Reilly, P, Mazur, O, Kelly, S, Liu, X, Maharjan, A, Dahal, A, Haque, N, Pradhan, A, Shrestha, S, Joshi, M, Smith, N, Hill, J, Clarke, J, Stockdale, L, Jones, E, Lubinda, T, Bajracharya, B, Dongol, S, Karkey, A, Baker, S, Dougan, G, Pitzer, VE, Neuzil, KM, Basnyat, B, Pollard, AJ
Format: Journal article
Language:English
Published: Elsevier 2021
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author Shakya, M
Voysey, M
Theiss-Nyland, K
Colin-Jones, R
Pant, D
Adhikari, A
Tonks, S
Mujadidi, YF
O'Reilly, P
Mazur, O
Kelly, S
Liu, X
Maharjan, A
Dahal, A
Haque, N
Pradhan, A
Shrestha, S
Joshi, M
Smith, N
Hill, J
Clarke, J
Stockdale, L
Jones, E
Lubinda, T
Bajracharya, B
Dongol, S
Karkey, A
Baker, S
Dougan, G
Pitzer, VE
Neuzil, KM
Shrestha, S
Basnyat, B
Pollard, AJ
author_facet Shakya, M
Voysey, M
Theiss-Nyland, K
Colin-Jones, R
Pant, D
Adhikari, A
Tonks, S
Mujadidi, YF
O'Reilly, P
Mazur, O
Kelly, S
Liu, X
Maharjan, A
Dahal, A
Haque, N
Pradhan, A
Shrestha, S
Joshi, M
Smith, N
Hill, J
Clarke, J
Stockdale, L
Jones, E
Lubinda, T
Bajracharya, B
Dongol, S
Karkey, A
Baker, S
Dougan, G
Pitzer, VE
Neuzil, KM
Shrestha, S
Basnyat, B
Pollard, AJ
author_sort Shakya, M
collection OXFORD
description <br><strong>Background<br></strong> Typhoid fever is a major public health problem in low-resource settings. Vaccination can help curb the disease and might reduce transmission. We have previously reported an interim analysis of the efficacy of typhoid conjugate vaccine (TCV) in Nepali children. Here we report the final results after 2 years of follow-up. <br><strong> Methods<br></strong> We did a participant-masked and observer-masked individually randomised trial in Lalitpur, Nepal, in which 20 019 children aged 9 months to younger than 16 years were randomly assigned in a 1:1 ratio to receive a single dose of TCV (Typbar TCV, Bharat Biotech International, India) or capsular group A meningococcal conjugate vaccine (MenA). Participants were followed up until April 9, 2020. The primary outcome was blood culture-confirmed typhoid fever. Cases were captured via passive surveillance and active telephone surveillance followed by medical record review. The trial is registered at ISRCTN registry, ISRCTN43385161 and is ongoing. <br><strong> Findings<br></strong> From Nov 20, 2017, to April 9, 2018, of 20 119 children screened, 20 019 participants were randomly assigned to receive TCV or MenA vaccine. There were 75 cases of blood culture-confirmed typhoid fever included in the analysis (13 in the TCV group and 62 in the MenA group) over the 2-year period. The protective efficacy of TCV against blood culture-confirmed typhoid fever at 2 years was 79·0% (95% CI 61·9–88·5; p<0·0001). The incidence of typhoid fever was 72 (95% CI 38–123) cases per 100 000 person-years in the TCV group and 342 (95% CI 262–438) cases per 100 000 person-years in the MenA group. Adverse events occurring within the first 7 days post-vaccination were reported previously. <br><strong> Interpretation<br></strong> The final results of this randomised, controlled trial are in keeping with the results of our published interim analysis. There is no evidence of waning protection over a 2-year period. These findings add further support for the WHO recommendations on control of enteric fever. <br><strong> Funding<br></strong> Bill & Melinda Gates Foundation.
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spelling oxford-uuid:bbe4e261-fba1-46b8-80c1-35e522d062b92022-03-27T05:20:30ZEfficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trialJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bbe4e261-fba1-46b8-80c1-35e522d062b9EnglishSymplectic ElementsElsevier2021Shakya, MVoysey, MTheiss-Nyland, KColin-Jones, RPant, DAdhikari, ATonks, SMujadidi, YFO'Reilly, PMazur, OKelly, SLiu, XMaharjan, ADahal, AHaque, NPradhan, AShrestha, SJoshi, MSmith, NHill, JClarke, JStockdale, LJones, ELubinda, TBajracharya, BDongol, SKarkey, ABaker, SDougan, GPitzer, VENeuzil, KMShrestha, SBasnyat, BPollard, AJ<br><strong>Background<br></strong> Typhoid fever is a major public health problem in low-resource settings. Vaccination can help curb the disease and might reduce transmission. We have previously reported an interim analysis of the efficacy of typhoid conjugate vaccine (TCV) in Nepali children. Here we report the final results after 2 years of follow-up. <br><strong> Methods<br></strong> We did a participant-masked and observer-masked individually randomised trial in Lalitpur, Nepal, in which 20 019 children aged 9 months to younger than 16 years were randomly assigned in a 1:1 ratio to receive a single dose of TCV (Typbar TCV, Bharat Biotech International, India) or capsular group A meningococcal conjugate vaccine (MenA). Participants were followed up until April 9, 2020. The primary outcome was blood culture-confirmed typhoid fever. Cases were captured via passive surveillance and active telephone surveillance followed by medical record review. The trial is registered at ISRCTN registry, ISRCTN43385161 and is ongoing. <br><strong> Findings<br></strong> From Nov 20, 2017, to April 9, 2018, of 20 119 children screened, 20 019 participants were randomly assigned to receive TCV or MenA vaccine. There were 75 cases of blood culture-confirmed typhoid fever included in the analysis (13 in the TCV group and 62 in the MenA group) over the 2-year period. The protective efficacy of TCV against blood culture-confirmed typhoid fever at 2 years was 79·0% (95% CI 61·9–88·5; p<0·0001). The incidence of typhoid fever was 72 (95% CI 38–123) cases per 100 000 person-years in the TCV group and 342 (95% CI 262–438) cases per 100 000 person-years in the MenA group. Adverse events occurring within the first 7 days post-vaccination were reported previously. <br><strong> Interpretation<br></strong> The final results of this randomised, controlled trial are in keeping with the results of our published interim analysis. There is no evidence of waning protection over a 2-year period. These findings add further support for the WHO recommendations on control of enteric fever. <br><strong> Funding<br></strong> Bill & Melinda Gates Foundation.
spellingShingle Shakya, M
Voysey, M
Theiss-Nyland, K
Colin-Jones, R
Pant, D
Adhikari, A
Tonks, S
Mujadidi, YF
O'Reilly, P
Mazur, O
Kelly, S
Liu, X
Maharjan, A
Dahal, A
Haque, N
Pradhan, A
Shrestha, S
Joshi, M
Smith, N
Hill, J
Clarke, J
Stockdale, L
Jones, E
Lubinda, T
Bajracharya, B
Dongol, S
Karkey, A
Baker, S
Dougan, G
Pitzer, VE
Neuzil, KM
Shrestha, S
Basnyat, B
Pollard, AJ
Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title_full Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title_fullStr Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title_full_unstemmed Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title_short Efficacy of typhoid conjugate vaccine in Nepal: final results of a phase 3, randomised, controlled trial
title_sort efficacy of typhoid conjugate vaccine in nepal final results of a phase 3 randomised controlled trial
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