scholarly journals Impact of Rotavirus Vaccine Introduction and Vaccine Effectiveness in the Republic of Moldova

2016 ◽  
Vol 62 (suppl 2) ◽  
pp. S140-S146 ◽  
Author(s):  
Stela Gheorghita ◽  
Ludmila Birca ◽  
Ala Donos ◽  
Annemarie Wasley ◽  
Ion Birca ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Republic Of Moldova ◽  
Vaccine Introduction ◽  
The Republic

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.

Detection of rotavirus before and after monovalent rotavirus vaccine introduction and vaccine effectiveness among children in mainland Tanzania

Vaccine ◽  
2018 ◽  
Vol 36 (47) ◽  
pp. 7149-7156 ◽  
Author(s):  
Bhavin Jani ◽  
Adolfine Hokororo ◽  
Jackson Mchomvu ◽  
Margaret M. Cortese ◽  
Christopher Kamugisha ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Vaccine Introduction ◽  
Before And After

scholarly journals Modeling of rotavirus transmission dynamics and impact of vaccination in Ghana

2020 ◽  
Author(s):  
Ernest O. Asare ◽  
Mohammad A. Al-Mamun ◽  
George E. Armah ◽  
Benjamin A. Lopman ◽  
Umesh D. Parashar ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Response Rate ◽  
Transmission Rate ◽  
Age Distribution ◽  
Vaccine Effectiveness ◽  
Rotavirus Vaccine ◽  
Vaccine Response ◽  
Maternal Immunity ◽  
Vaccine Introduction ◽  
Vaccine Impact

AbstractBackgroundRotavirus incidence remains relatively high in low-income countries (LICs) compared to high-income countries (HICs) after vaccine introduction. Ghana introduced monovalent rotavirus vaccine in April 2012 and despite the high coverage, vaccine performance has been modest compared to developed countries. The predictors of low vaccine effectiveness in LICs are poorly understood, and the drivers of subnational heterogeneity in rotavirus vaccine impact are unknown.MethodsWe used mathematical models to investigate variations in rotavirus incidence in children <5 years old in Ghana. We fit models to surveillance and case-control data from three different hospitals: Korle-Bu Teaching Hospital in Accra, Komfo Anokye Teaching Hospital in Kumasi, and War Memorial Hospital in Navrongo. The models were fitted to both pre- and post-vaccine data to estimate parameters describing the transmission rate, waning of maternal immunity, and vaccine response rate.ResultsThe seasonal pattern and age distribution of rotavirus cases varied among the three study sites in Ghana. Our model was able to capture the spatio-temporal variations in rotavirus incidence across the three sites and showed good agreement with the age distribution of observed cases. The rotavirus transmission rate was highest in Accra and lowest in Navrongo, while the estimated duration of maternal immunity was longer (∼5 months) in Accra and Kumasi and shorter (∼3 months) in Navrongo. The proportion of infants who responded to the vaccine was estimated to be high in Accra and Kumasi and low in Navrongo.ConclusionsRotavirus vaccine impact varies within Ghana. A low vaccine response rate was estimated for Navrongo, where rotavirus is highly seasonal and incidence limited to a few months of the year. Our findings highlight the need to further explore the relationship between rotavirus seasonality, maternal immunity, and vaccine response rate to determine how they influence vaccine effectiveness and to develop strategies to improve vaccine impact.HighlightsMarked variations in rotavirus incidence and vaccine impact within GhanaSimilar rotavirus seasonality before and after vaccine introductionA shift in age distribution occurred following vaccine introductionThe models provide satisfactory predictions of rotavirus outbreaks and vaccine impact

scholarly journals Monovalent Rotavirus Vaccine Effectiveness Against Rotavirus Hospitalizations Among Children in Zimbabwe

2018 ◽  
Vol 69 (8) ◽  
pp. 1339-1344 ◽  
Author(s):  
Hilda A Mujuru ◽  
Eleanor Burnett ◽  
Kusum J Nathoo ◽  
Ismail Ticklay ◽  
Nhamo A Gonah ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Vaccination Status ◽  
Watery Diarrhea ◽  
Rotavirus Vaccine ◽  
Normal Height ◽  
Severe Diarrhea ◽  
Vaccine Introduction ◽  
Rotavirus Vaccines ◽  
Negative Case ◽  
Acute Watery Diarrhea

Abstract Background Rotavirus is a leading cause of mortality among children <5 years old. We evaluated monovalent rotavirus vaccine effectiveness (VE) under conditions of routine use at 2 surveillance sites in Harare, Zimbabwe, after vaccine introduction in May 2014. Methods Children aged <5 years hospitalized or treated in the accident and emergency department (A&E) for acute watery diarrhea were enrolled for routine surveillance. Copies of vaccination cards were collected to document vaccination status. Among children age-eligible to receive rotavirus vaccine, we estimated VE, calculated as 1 – odds ratio, using a test-negative case-control design Results We included 903 rotavirus-positive cases and 2685 rotavirus-negative controls in the analysis; 99% had verified vaccination status. Rotavirus-positive children had more severe diarrhea than rotavirus-negative children; 61% of cases and 46% of controls had a Vesikari score ≥11 (P < .01). Among cases and controls, 31% and 37%, respectively, were stunted for their age (P < .01). Among children 6–11 months old, adjusted 2-dose VE against hospitalization or treatment in A&E due to rotavirus of any severity was 61% (95% confidence interval [CI], 21%–81%) and 68% (95% CI, 13%–88%) against severe rotavirus disease. Stratified by nutritional status, adjusted VE was 45% (95% CI, –148% to 88%) among stunted infants and 71% (95% CI, 29%–88%) among infants with a normal height for age Conclusions Monovalent rotavirus vaccine is effective in preventing hospitalizations due to severe rotavirus diarrhea among infants in Zimbabwe, providing additional evidence for countries considering rotavirus vaccine introduction that live, oral rotavirus vaccines are effective in high-child-mortality settings.

Promoting and supporting physical activity and sport among young people in the Republic of Moldova

2018 ◽  
Vol 13 (3) ◽  
pp. 158-164
Author(s):  
Serghei Cebanu ◽  
◽  
Mariana Tutunaru ◽  
Raisa Deleu ◽  
Angela Cazacu-Stratu ◽  
...  
Keyword(s):  
Physical Activity ◽  
Young People ◽  
Republic Of Moldova ◽  
The Republic

Republic of Moldova in the Context of Regional Security Challenges in Eastern Europe

2018 ◽  
pp. 299-304
Author(s):  
Stefan Tibuleac
Keyword(s):  
Eastern Europe ◽  
Security Policy ◽  
Security System ◽  
Regional Security ◽  
Strategic Uncertainty ◽  
European Security ◽  
Republic Of Moldova ◽  
The Republic ◽  
The Impact

This article analyzes the most current security issues for the Republic of Moldova that are part of the regional security context of Eastern Europe –the region that can be considered the epicenter of international tensions through which the„geopolitical line of fracture”passes. The geographical position of the Republic of Moldova makes this state particularly sensitive to any negative trends in theregion. Growing of international tensions creates security threats and complicates economic development. From a historical point of view, Moldova has repeatedly fallen victim by the confrontation of the great powers. Therefore, the Republic of Moldova has a vital interest in preventing a new conflict in Eastern Europe. This article is based on a number of assumptions made by changes in the European security environment, such as the „shift of weight” to the East, strategic uncertainty, increasing the role of non-state actors, the situation in eastern Ukraine, etc. Based on these assumptions, this article makes an attempt to outline the potential role of the Republic of Moldova in the Eastern European security system, taking into account the desideratum for integration of the republic into the European Union. Other relevant factors will be taken into account for shaping the role of the Republic of Moldova in the European security system, namely: the security deficit; the impact of NATO and EU security policy; the rebirth of the project to create a regional defense alliance, etc. This article will largely take into account the military aspects of security. Keywords: Republic of Moldova, national security, Eastern Europe, NATO, Intermarium, defence, threats, risks, challenges

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