Rapid Disappearance of Poliovirus Type 2 (PV2) Immunity in Young Children Following Withdrawal of Oral PV2-Containing Vaccine in Vietnam.
J Infect Dis
; 220(3): 386-391, 2019 07 02.
Article
en En
| MEDLINE
| ID: mdl-30869149
ABSTRACT
BACKGROUND:
Due to global shortage of inactivated poliovirus vaccine and withdrawal of oral vaccine containing poliovirus type 2 (PV2), a PV2-containing vaccine was not used in Vietnam May 2016 to October 2018. We assessed the population immunity gap to PV2.METHODS:
A cross-sectional survey in children aged 1-18 months was carried out in January 2018. One blood sample per child was analyzed for presence of poliovirus neutralizing antibodies. In children with detectable anti-PV2 antibodies, a second sample was analyzed 4 months later to distinguish between passive (maternally derived) and active (induced by secondary transmission or vaccination) immunity.RESULTS:
Sera were obtained from 1106/1110 children. Seroprevalence of PV2 antibodies was 87/368 (23.6%) at age 1-7 months, 27/471 (5.7%) at 8-15 months, and 19/267 (7.1%) at 16-18 months. Seroprevalence declined with age in the 1-7 months group; in the 8-18 months group there was no significant change with age. Four months later, 11/87 (14%), 9/27 (32%), and 12/19 (37%) remained seropositive in 1-7, 8-15, and 16-18 months age groups, respectively.CONCLUSIONS:
We found declining immunity to PV2, suggesting Vietnam is at risk for an outbreak of type 2 vaccine-derived poliovirus following virus importation or new emergence.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Vacuna Antipolio de Virus Inactivados
/
Vacuna Antipolio Oral
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Poliovirus
Tipo de estudio:
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Límite:
Child, preschool
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Female
/
Humans
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Infant
/
Male
País/Región como asunto:
Asia
Idioma:
En
Revista:
J Infect Dis
Año:
2019
Tipo del documento:
Article
País de afiliación:
Vietnam