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[Analysis on the immuno-effects of two different Japanese encephalitis virus vaccines]
Insights
Japanese encephalitis virus (JEV) vaccines, both inactivated and live attenuated, show varying antibody response rates in infants. Booster doses are crucial for achieving protective immunity against JEV.
Area of Science:
- Pediatric Infectious Diseases
- Vaccinology
- Immunology
Background:
- Japanese encephalitis virus (JEV) poses a significant public health threat, particularly in Asian countries.
- Infant immunization is critical for establishing early protection against JEV.
- Understanding the immunogenicity of different JEV vaccine types in infants is essential for optimizing vaccination schedules.
Purpose of the Study:
- To compare the immunogenicity of an inactivated JEV vaccine and a live attenuated JEV vaccine in infants.
- To determine optimal primary and booster immunization schedules for both vaccine types in infants aged 5-18 months.
- To evaluate serum antibody positive rates at various time points post-vaccination.
Main Methods:
- A study involving 319 infants aged 5-18 months, divided into two groups.
- One group received inactivated JEV vaccine, the other received live attenuated JEV vaccine.
- Serum antibody levels were measured before immunization, after primary immunization, and at multiple time points after booster doses.
Main Results:
- Initial antibody positive rates were low (3.76%) before vaccination.
- Primary immunization with inactivated and live attenuated vaccines resulted in positive rates of 59.56% and 56.08%, respectively, below protective levels.
- Booster doses one year later significantly increased antibody rates to 94.62% and 98.21% (1 month post-booster).
- Six months post-booster, rates were 72.34% (inactivated) and 94.74% (live attenuated).
Conclusions:
- The inactivated JEV vaccine requires a primary series of two doses (7-10 day interval) with boosters in years 2 and 3.
- The live attenuated JEV vaccine requires a single primary dose with boosters in year 2 and again 4-5 years later.
- Both vaccine types, with appropriate schedules, can induce protective antibody levels against Japanese encephalitis in infants.
Abstract:
319 infants aged 5-18 months were divided in to 2 groups and immunized with Japanese encephalitis virus inactivated vaccine and live attenuated vaccine respectively. Under the detection of serum antibody, a 3.76% serum antibody positive rate was revealed before the immunization. However, after the basic immunization the serum positive rates of the two vaccines reached 59.56% and 56.08% respectively but still under the protective level. The infants were then given booster injection one year later. The serum positive rates reached 94.62% and 98.21% respectively 1 month later. When six months after the booster immunization, the positive rates were 72.34% and 94.74% respectively. According to the results, the following immunization order was recommend. For inactivated vaccine: 2 injections are given with an interval of 7-10 days for basic immunization and booster immunization be given in the second and third years. For live attenuated vaccine: one injection is given for basic immunization then booster dose be given in the second year and 4-5 years later.