Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines.
BACKGROUND:Mass drug administration (MDA) of praziquantel has been the intervention of choice against schistosomiasis but with limited success in interrupting the transmission. The development of anti-Schistosoma vaccines is underway. Our objective is to quantify the population-level impact of anti-...
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ftdoajarticles:oai:doaj.org/article:b8243e2ef4d248868981cded1cbd11b1 2023-05-15T15:11:46+02:00 Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. Ramzi A Alsallaq David Gurarie Martial Ndeffo Mbah Alison Galvani Charles King 2017-04-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0005544 https://doaj.org/article/b8243e2ef4d248868981cded1cbd11b1 EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC5406007?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0005544 https://doaj.org/article/b8243e2ef4d248868981cded1cbd11b1 PLoS Neglected Tropical Diseases, Vol 11, Iss 4, p e0005544 (2017) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2017 ftdoajarticles https://doi.org/10.1371/journal.pntd.0005544 2022-12-31T13:49:11Z BACKGROUND:Mass drug administration (MDA) of praziquantel has been the intervention of choice against schistosomiasis but with limited success in interrupting the transmission. The development of anti-Schistosoma vaccines is underway. Our objective is to quantify the population-level impact of anti-Schistosoma vaccines when administered alone and in combination with mass drug administration (MDA) and determine factors in vaccine design and public health implementation that optimize vaccination role in schistosomiasis control and elimination. METHODS AND FINDINGS:We developed a deterministic compartmental model simulation of schistosomiasis transmission in a high-risk Kenyan community, including stratification by age, parasite burden, and vaccination status. The modeled schistosomiasis vaccines differed in terms of vaccine duration of protection (durability) and three biological efficacies. These are vaccine susceptibility effect (SE) of reducing person's susceptibility to Schistosoma acquisition, vaccine mortality effect (ME) of reducing established worm burden and vaccine fecundity effect (FE) of reducing egg release by mature worms. We quantified the population-level impact of vaccination over two decades under diverse vaccination schemes (childhood vs. mass campaigns), with different age-targeting scenarios, different risk settings, and with combined intervention with MDA. We also assessed the sensitivity of our predictions to uncertainties in model parameters. Over two decades, our base case vaccine with 80% SE, FE, and ME efficacies, 10 years' durability, provided by mass vaccination every 10 years, reduced host prevalence, mean intensity, incidence, and patent snail prevalence to 31%, 20 eggs/10-ml sample/person, 0.87 worm/person-year, and 0.74%, from endemic-state values of 71%, 152, 3.3, and 0.98%, respectively. Lower impact was found when coverage did not encompass all potential contaminators, and childhood-only vaccination schemes showed delayed and lower impact. In lower prevalence settings, the base ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 11 4 e0005544 |
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Directory of Open Access Journals: DOAJ Articles |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Ramzi A Alsallaq David Gurarie Martial Ndeffo Mbah Alison Galvani Charles King Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
BACKGROUND:Mass drug administration (MDA) of praziquantel has been the intervention of choice against schistosomiasis but with limited success in interrupting the transmission. The development of anti-Schistosoma vaccines is underway. Our objective is to quantify the population-level impact of anti-Schistosoma vaccines when administered alone and in combination with mass drug administration (MDA) and determine factors in vaccine design and public health implementation that optimize vaccination role in schistosomiasis control and elimination. METHODS AND FINDINGS:We developed a deterministic compartmental model simulation of schistosomiasis transmission in a high-risk Kenyan community, including stratification by age, parasite burden, and vaccination status. The modeled schistosomiasis vaccines differed in terms of vaccine duration of protection (durability) and three biological efficacies. These are vaccine susceptibility effect (SE) of reducing person's susceptibility to Schistosoma acquisition, vaccine mortality effect (ME) of reducing established worm burden and vaccine fecundity effect (FE) of reducing egg release by mature worms. We quantified the population-level impact of vaccination over two decades under diverse vaccination schemes (childhood vs. mass campaigns), with different age-targeting scenarios, different risk settings, and with combined intervention with MDA. We also assessed the sensitivity of our predictions to uncertainties in model parameters. Over two decades, our base case vaccine with 80% SE, FE, and ME efficacies, 10 years' durability, provided by mass vaccination every 10 years, reduced host prevalence, mean intensity, incidence, and patent snail prevalence to 31%, 20 eggs/10-ml sample/person, 0.87 worm/person-year, and 0.74%, from endemic-state values of 71%, 152, 3.3, and 0.98%, respectively. Lower impact was found when coverage did not encompass all potential contaminators, and childhood-only vaccination schemes showed delayed and lower impact. In lower prevalence settings, the base ... |
format |
Article in Journal/Newspaper |
author |
Ramzi A Alsallaq David Gurarie Martial Ndeffo Mbah Alison Galvani Charles King |
author_facet |
Ramzi A Alsallaq David Gurarie Martial Ndeffo Mbah Alison Galvani Charles King |
author_sort |
Ramzi A Alsallaq |
title |
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
title_short |
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
title_full |
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
title_fullStr |
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
title_full_unstemmed |
Quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
title_sort |
quantitative assessment of the impact of partially protective anti-schistosomiasis vaccines. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2017 |
url |
https://doi.org/10.1371/journal.pntd.0005544 https://doaj.org/article/b8243e2ef4d248868981cded1cbd11b1 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 11, Iss 4, p e0005544 (2017) |
op_relation |
http://europepmc.org/articles/PMC5406007?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0005544 https://doaj.org/article/b8243e2ef4d248868981cded1cbd11b1 |
op_doi |
https://doi.org/10.1371/journal.pntd.0005544 |
container_title |
PLOS Neglected Tropical Diseases |
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11 |
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4 |
container_start_page |
e0005544 |
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1766342568857042944 |