Gayane Sahakyan1, Svetlana Grigoryan2, Annemarie Wasley3, Liudmila Mosina3, Shushan Sargsyan4, Ara Asoyan5, Zaruhi Gevorgyan5, Karine Kocharyan6, Tigran Avagyan7, Benjamin Lopman8, Artavazd Vanyan4, Sergey Khactatryan9, Umesh D Parashar8, Margaret M Cortese8. 1. National Immunization Program National Centre of Disease Control and Prevention Ministry of Health of the Republic of Armenia. 2. National Centre of Disease Control and Prevention Ministry of Health of the Republic of Armenia Immunization and Epidemiology of Vaccine-Preventable Diseases, Yerevan, Armenia. 3. Vaccine-Preventable Diseases and Immunization, World Health Organization Regional Office for Europe, Copenhagen, Denmark. 4. National Centre of Disease Control and Prevention Ministry of Health of the Republic of Armenia. 5. Nork Infection Hospital, Country Office of Armenia, Yerevan. 6. Arabkir Medical Centre, Country Office of Armenia, Yerevan. 7. World Health Organization, Country Office of Armenia, Yerevan. 8. Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia. 9. Ministry of Health of the Republic of Armenia.
Abstract
BACKGROUND: The Republic of Armenia was 1 of the 2 earliest countries in the Newly Independent States to introduce rotavirus vaccine into its national immunization program to reduce the burden of rotavirus disease (documented to cause 38% of acute gastroenteritis hospitalizations [AGE] among children aged <5 years). In November 2012, RV1 (Rotarix) was introduced for Armenian infants at ages 6 and 12 weeks. METHODS: The established active surveillance system at 2 hospitals in the capital, Yerevan, whereby children aged <5 years hospitalized for AGE have stool sample tested for rotavirus antigen, was used to assess trends in rotavirus hospitalizations. Immunization records on children enrolled after vaccine introduction were obtained from clinics, and vaccine effectiveness (VE) was estimated using children with AGE who test negative for rotavirus as controls for the rotavirus-positive cases. RESULTS: Among infants, rotavirus hospitalizations were reduced by 48% within the first year after introduction, and by ≥75% in years 2 and 3 following introduction. Reductions of ≥30% in other young children too old to have been vaccinated suggest additional benefit through indirect protection; overall in year 3, rotavirus hospitalizations were reduced by 69% among children aged <5 years. The overall VE of 2 RV1 doses in protecting against rotavirus hospitalization (any severity) was 62% (95% confidence interval [CI], 36%-77%) among children aged 6-23 months; 68% (95% CI, 24%-86%) among those aged 6-11 months, and 60% (95% CI, 20%-80%) in children aged 12-23 months. Against more severe rotavirus disease, VE was 79% (95% CI, 55%-90%) and similarly high in both age groups. CONCLUSIONS: RV1 is effective in young Armenian children and substantially reduced rotavirus hospitalizations shortly after introduction. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.
BACKGROUND: The Republic of Armenia was 1 of the 2 earliest countries in the Newly Independent States to introduce rotavirus vaccine into its national immunization program to reduce the burden of rotavirus disease (documented to cause 38% of acute gastroenteritis hospitalizations [AGE] among children aged <5 years). In November 2012, RV1 (Rotarix) was introduced for Armenian infants at ages 6 and 12 weeks. METHODS: The established active surveillance system at 2 hospitals in the capital, Yerevan, whereby children aged <5 years hospitalized for AGE have stool sample tested for rotavirus antigen, was used to assess trends in rotavirus hospitalizations. Immunization records on children enrolled after vaccine introduction were obtained from clinics, and vaccine effectiveness (VE) was estimated using children with AGE who test negative for rotavirus as controls for the rotavirus-positive cases. RESULTS: Among infants, rotavirus hospitalizations were reduced by 48% within the first year after introduction, and by ≥75% in years 2 and 3 following introduction. Reductions of ≥30% in other young children too old to have been vaccinated suggest additional benefit through indirect protection; overall in year 3, rotavirus hospitalizations were reduced by 69% among children aged <5 years. The overall VE of 2 RV1 doses in protecting against rotavirus hospitalization (any severity) was 62% (95% confidence interval [CI], 36%-77%) among children aged 6-23 months; 68% (95% CI, 24%-86%) among those aged 6-11 months, and 60% (95% CI, 20%-80%) in children aged 12-23 months. Against more severe rotavirus disease, VE was 79% (95% CI, 55%-90%) and similarly high in both age groups. CONCLUSIONS: RV1 is effective in young Armenian children and substantially reduced rotavirus hospitalizations shortly after introduction. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.
Authors: Huiying Chua; Shuo Feng; Joseph A Lewnard; Sheena G Sullivan; Christopher C Blyth; Marc Lipsitch; Benjamin J Cowling Journal: Epidemiology Date: 2020-01 Impact factor: 4.822
Authors: Liudmyla I Chernyshova; Nataliya M Radionova; Iryna V Demchyshyna; Liudmyla S Kotlik; Oleksandra B Sadkova; Elena O Samoilovich; Galina V Semeiko; Danni S Daniels; Adam L Cohen; Negar Aliabadi Journal: Vaccine Date: 2017-12-01 Impact factor: 4.169