scholarly journals Rotavirus vaccine effectiveness in low-income settings: An evaluation of the test-negative design

Vaccine ◽  
2017 ◽  
Vol 35 (1) ◽  
pp. 184-190 ◽  
Author(s):  
Lauren M. Schwartz ◽  
M. Elizabeth Halloran ◽  
Ali Rowhani-Rahbar ◽  
Kathleen M. Neuzil ◽  
John C. Victor
Keyword(s):  
Low Income ◽  
Vaccine Effectiveness ◽  
Rotavirus Vaccine

scholarly journals Evaluating strategies to improve rotavirus vaccine impact during the second year of life in Malawi

2019 ◽  
Vol 11 (505) ◽  
pp. eaav6419 ◽  
Author(s):  
Virginia E. Pitzer ◽  
Aisleen Bennett ◽  
Naor Bar-Zeev ◽  
Khuzwayo C. Jere ◽  
Benjamin A. Lopman ◽  
...  
Keyword(s):  
Low Income ◽  
Transmission Rate ◽  
Natural Infection ◽  
Vaccine Effectiveness ◽  
Low Income Countries ◽  
Rotavirus Vaccine ◽  
Second Year Of Life ◽  
Vaccine Impact ◽  
Second Year ◽  
Induced Immunity

Rotavirus vaccination has substantially reduced the incidence of rotavirus-associated gastroenteritis (RVGE) in high-income countries, but vaccine impact and estimated effectiveness are lower in low-income countries for reasons that are poorly understood. We used mathematical modeling to quantify rotavirus vaccine impact and investigate reduced vaccine effectiveness, particularly during the second year of life, in Malawi, where vaccination was introduced in October 2012 with doses at 6 and 10 weeks. We fitted models to 12 years of prevaccination data and validated the models against postvaccination data to evaluate the magnitude and duration of vaccine protection. The observed rollout of vaccination in Malawi was predicted to lead to a 26 to 77% decrease in the overall incidence of moderate-to-severe RVGE in 2016, depending on assumptions about waning of vaccine-induced immunity and heterogeneity in vaccine response. Vaccine effectiveness estimates were predicted to be higher among 4- to 11-month-olds than 12- to 23-month-olds, even when vaccine-induced immunity did not wane, due to differences in the rate at which vaccinated and unvaccinated individuals acquire immunity from natural infection. We found that vaccine effectiveness during the first and second years of life could potentially be improved by increasing the proportion of infants who respond to vaccination or by lowering the rotavirus transmission rate. An additional dose of rotavirus vaccine at 9 months of age was predicted to lead to higher estimated vaccine effectiveness but to only modest (5 to 16%) reductions in RVGE incidence over the first 3 years after introduction, regardless of assumptions about waning of vaccine-induced immunity.

scholarly journals Community transmission of rotavirus infection in a vaccinated population in Malawi: a prospective household cohort study

2020 ◽  
Author(s):  
Aisleen Bennett ◽  
Louisa Pollock ◽  
Naor Bar-Zeev ◽  
Joseph A. Lewnard ◽  
Khuzwayo C. Jere ◽  
...  
Keyword(s):  
Low Income ◽  
Asymptomatic Infection ◽  
Vaccine Effectiveness ◽  
Low Income Countries ◽  
Rotavirus Vaccine ◽  
Rotavirus Infection ◽  
Indirect Transmission ◽  
Household Contacts ◽  
Asymptomatic Children ◽  
Increased Risk

AbstractBackgroundRotavirus vaccine effectiveness (VE) is reduced among children in low-income countries (LICs). Indirect (transmission-mediated) effects of rotavirus vaccine may contribute to the total population impact of vaccination. We estimated the effectiveness of rotavirus vaccine in preventing transmission of rotavirus to household contacts in Blantyre, Malawi.MethodsWe recruited vaccine-age-eligible children with acute rotavirus gastroenteritis (case-children), together with their household contacts. Clinical data and stool samples were collected from case-children at presentation, and prospectively from household contacts over 14 days. A single stool sample was collected from control households containing asymptomatic children age-matched to case-children. Samples were tested for rotavirus using real-time PCR. Risk factors for household transmission of rotavirus infection and clinical rotavirus disease were identified using logistic regression. Vaccine effectiveness against transmission (VET) was estimated as one minus the ratio of secondary attack rates (SAR) in vaccinated and unvaccinated populations, using VE estimates from the associated diarrhoeal surveillance platform to estimate the counterfactual SAR without vaccination.FindingsA total of 196 case-households and 55 control-households were recruited. Household SAR for rotavirus infection was high (65%); SAR for clinical disease was much lower (5%). Asymptomatic infection in control households was common (28%). Increasing disease severity was associated with increased risk of transmission of both rotavirus infection and disease to household contacts. Estimated VET was 39% (95% confidence interval 16-57%).InterpretationRotavirus vaccine has the potential to substantially reduce household rotavirus transmission. This should be considered in clinical and health economic assessments of vaccine impact.FundingWellcome Trust and NIH/NIAID.

scholarly journals The Rotavirus Vaccine Landscape, an Update

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 520
Author(s):  
Roberto Cárcamo-Calvo ◽  
Carlos Muñoz ◽  
Javier Buesa ◽  
Jesús Rodríguez-Díaz ◽  
Roberto Gozalbo-Rovira
Keyword(s):  
Developing Countries ◽  
Mortality Rate ◽  
Low Income ◽  
State Of The Art ◽  
The State ◽  
Cold Chain ◽  
Low Income Countries ◽  
Rotavirus Vaccine ◽  
Oral Vaccines

Rotavirus is the leading cause of severe acute childhood gastroenteritis, responsible for more than 128,500 deaths per year, mainly in low-income countries. Although the mortality rate has dropped significantly since the introduction of the first vaccines around 2006, an estimated 83,158 deaths are still preventable. The two main vaccines currently deployed, Rotarix and RotaTeq, both live oral vaccines, have been shown to be less effective in developing countries. In addition, they have been associated with a slight risk of intussusception, and the need for cold chain maintenance limits the accessibility of these vaccines to certain areas, leaving 65% of children worldwide unvaccinated and therefore unprotected. Against this backdrop, here we review the main vaccines under development and the state of the art on potential alternatives.

scholarly journals Case-Control Study of Rotavirus Vaccine Effectiveness Compared to Test-Negative Controls or Hospital Controls

2019 ◽  
Vol 29 (8) ◽  
pp. 282-287 ◽  
Author(s):  
Kaoru Araki ◽  
Megumi Hara ◽  
Chisato Shimanoe ◽  
Yuichiro Nishida ◽  
Muneaki Matsuo ◽  
...  
Keyword(s):  
Case Control Study ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Negative Controls ◽  
Control Study

scholarly journals Effect of Age at Vaccination on Rotavirus Vaccine Effectiveness in Bolivian Infants

2018 ◽  
Vol 37 (8) ◽  
pp. e216-e221 ◽  
Author(s):  
Rachel M. Burke ◽  
Jacqueline E. Tate ◽  
Kimberly D. Pringle ◽  
Manish Patel ◽  
Lucia H. De Oliveira ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Effect Of Age

scholarly journals Rotavirus vaccine effectiveness and impact in Uzbekistan, the first country to introduce in central Asia

2020 ◽  
pp. 1-7
Author(s):  
Umid Eraliev ◽  
Renat Latipov ◽  
Dilorom Tursunova ◽  
Annemarie Wasley ◽  
Danni Daniels ◽  
...  
Keyword(s):  
Central Asia ◽  
Vaccine Effectiveness ◽  
Rotavirus Vaccine

Monovalent Rotavirus Vaccine Effectiveness and Impact on Rotavirus Hospitalizations in Zanzibar, Tanzania: Data From the First 3 Years After Introduction

2016 ◽  
pp. jiw524 ◽  
Author(s):  
Khamis Ali Abeid ◽  
Bhavin Jani ◽  
Margaret M. Cortese ◽  
Christopher Kamugisha ◽  
Jason M. Mwenda ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Rotavirus Vaccine

scholarly journals Long-term Consistency in Rotavirus Vaccine Protection: RV5 and RV1 Vaccine Effectiveness in US Children, 2012–2013

2015 ◽  
Vol 61 (12) ◽  
pp. 1792-1799 ◽  
Author(s):  
Daniel C. Payne ◽  
Rangaraj Selvarangan ◽  
Parvin H. Azimi ◽  
Julie A. Boom ◽  
Janet A. Englund ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Vaccine Protection ◽  
Us Children

scholarly journals Emergence of Double- and Triple-Gene Reassortant G1P[8] Rotaviruses Possessing a DS-1-Like Backbone after Rotavirus Vaccine Introduction in Malawi

2017 ◽  
Vol 92 (3) ◽  
Author(s):  
Khuzwayo C. Jere ◽  
Chrispin Chaguza ◽  
Naor Bar-Zeev ◽  
Jenna Lowe ◽  
Chikondi Peno ◽  
...  
Keyword(s):  
Amino Acid ◽  
Vaccine Effectiveness ◽  
Recent Common Ancestor ◽  
Rotavirus Vaccine ◽  
Careful Evaluation ◽  
African Countries ◽  
Vaccine Introduction ◽  
Rotavirus Gastroenteritis ◽  
Structural Conformation ◽  
Rotavirus Vaccines

ABSTRACT To combat the high burden of rotavirus gastroenteritis, multiple African countries have introduced rotavirus vaccines into their childhood immunization programs. Malawi incorporated a G1P[8] rotavirus vaccine (Rotarix) into its immunization schedule in 2012. Utilizing a surveillance platform of hospitalized rotavirus gastroenteritis cases, we examined the phylodynamics of G1P[8] rotavirus strains that circulated in Malawi before (1998 to 2012) and after (2013 to 2014) vaccine introduction. Analysis of whole genomes obtained through next-generation sequencing revealed that all randomly selected prevaccine G1P[8] strains sequenced ( n = 32) possessed a Wa-like genetic constellation, whereas postvaccine G1P[8] strains ( n = 18) had a DS-1-like constellation. Phylodynamic analyses indicated that postvaccine G1P[8] strains emerged through reassortment events between human Wa- and DS-1-like rotaviruses that circulated in Malawi from the 1990s and hence were classified as atypical DS-1-like reassortants. The time to the most recent common ancestor for G1P[8] strains was from 1981 to 1994; their evolutionary rates ranged from 9.7 × 10 −4 to 4.1 × 10 −3 nucleotide substitutions/site/year. Three distinct G1P[8] lineages chronologically replaced each other between 1998 and 2014. Genetic drift was the likely driver for lineage turnover in 2005, whereas replacement in 2013 was due to reassortment. Amino acid substitution within the outer glycoprotein VP7 of G1P[8] strains had no impact on the structural conformation of the antigenic regions, suggesting that it is unlikely that they would affect recognition by vaccine-induced neutralizing antibodies. While the emergence of DS-1-like G1P[8] rotavirus reassortants in Malawi was therefore likely due to natural genotype variation, vaccine effectiveness against such strains needs careful evaluation. IMPORTANCE The error-prone RNA-dependent RNA polymerase and the segmented RNA genome predispose rotaviruses to genetic mutation and genome reassortment, respectively. These evolutionary mechanisms generate novel strains and have the potential to lead to the emergence of vaccine escape mutants. While multiple African countries have introduced a rotavirus vaccine, there are few data describing the evolution of rotaviruses that circulated before and after vaccine introduction. We report the emergence of atypical DS-1-like G1P[8] strains during the postvaccine era in Malawi. Three distinct G1P[8] lineages circulated chronologically from 1998 to 2014; mutation and reassortment drove lineage turnover in 2005 and 2013, respectively. Amino acid substitutions within the outer capsid VP7 glycoprotein did not affect the structural conformation of mapped antigenic sites, suggesting a limited effect on the recognition of G1-specific vaccine-derived antibodies. The genes that constitute the remaining genetic backbone may play important roles in immune evasion, and vaccine effectiveness against such atypical strains needs careful evaluation.

scholarly journals Infrequent Transmission of Monovalent Human Rotavirus Vaccine Virus to Household Contacts of Vaccinated Infants in Malawi

2019 ◽  
Vol 219 (11) ◽  
pp. 1730-1734 ◽  
Author(s):  
Aisleen Bennett ◽  
Louisa Pollock ◽  
Khuzwayo C Jere ◽  
Virginia E Pitzer ◽  
Benjamin Lopman ◽  
...  
Keyword(s):  
Low Income ◽  
Indirect Effects ◽  
Horizontal Transmission ◽  
Vaccine Virus ◽  
Low Income Countries ◽  
Rotavirus Vaccine ◽  
Fecal Shedding ◽  
Household Contacts ◽  
Human Rotavirus ◽  
Stool Samples

Abstract Horizontal transmission of rotavirus vaccine virus may contribute to indirect effects of rotavirus vaccine, but data are lacking from low-income countries. Serial stool samples were obtained from Malawian infants who received 2 doses of monovalent human rotavirus vaccine (RV1) (days 4, 6, 8, and 10 after vaccination) and from their household contacts (8–10 days after vaccine). RV1 vaccine virus in stool was detected using semiquantitative real-time reverse-transcription polymerase chain reaction. RV1 fecal shedding was detected in 41 of 60 vaccinated infants (68%) and in 2 of 147 household contacts (1.4%). Horizontal transmission of vaccine virus within households is unlikely to make a major contribution to RV1 indirect effects in Malawi.

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