Page 451 - TBE_Book_V2_2019

Chapter 14: Prevention

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mouse brain cells). After 2 doses of the TBE- reduction neutralization test and/or ELISA)
Moscow vaccine given 4 months apart, 92% of ranged between 86.4% and 98.8% after 2
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children and adolescents ages 7–17 years doses. In the group of subjects ≥60 years old,
achieved a 4-fold rise in antibody levels the seropositivity rate 28 days after the
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compared with baseline. Based on these second vaccination was 97.3%. In 1 of the
results, the vaccine was recommended first studies, seropersistence rates of 86.5% and
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for use in children and later for use in adults. 76.9% were observed 6 and 12 months after
the second vaccination, respectively.
A study comparing EnceVir and TBE-Moscow
vaccine (N=400) found seropositivity (HI test) Comparative studies
in 82% and 89% of patients, respectively, after
2 doses of EnceVir given 2 or 5 months apart, A recent randomized study compared the
whereas the seropositivity rates with the TBE- immunogenicity of TBE-Moscow, EnceVir,
Moscow vaccine were 84% and 93%, FSME-IMMUN, and Encepur Adults by using
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respectively. 26–28 Furthermore, the 2 vaccines the Far-Eastern virus strain P-73 in adults. All
were also compared in 325 children who vaccines induced neutralizing antibodies
received 2 doses of either vaccine. A 4-fold against the tested strain with TBE-Moscow;
rise in HI titer was achieved in 84% to 97% of neutralizing antibodies were detected in 100%
the children with EnceVir and in 96% to 98% and 94% of the vaccinees after 2–5 months
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with TBE-Moscow vaccine, respectively. and 2 years, respectively. With EnceVir,
Twelve months after the last dose of EnceVir neutralizing antibody detection rates were
or TBE-Moscow vaccine, 72% and 87%, 88% and 84%; with FSME-IMMUN, 88.2% and
respectively, of the vaccinated individuals 78.1%; and with Encepur, 100% and 100%,
were still seropositive. A booster response respectively.
was efficacious in all of the 131 children who
received a third dose 1 year after the first 2 Irregular vaccination
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vaccinations.
The question of how to address prolonged
In studies comparing the available Russian TBE intervals between the vaccinations of the
vaccines, seroconversion rates of 59% and primary series or between the boosters has
83%, after 1 and 2 doses, respectively, were long been debated. An investigation of the
achieved with TBE-Moscow vaccine, versus field effectiveness of TBE vaccination in
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75% and 85%, respectively, with EnceVir. Austria – a country in which 88% of the total
Even without randomized controlled efficacy population is vaccinated against TBE at least
trials, the field effectiveness of the 2 Russian once and 58% is regularly vaccinated
vaccines has been proven in highly endemic according to the recommended schedule –
regions, e.g., in Krasnoyarsk and Sverdlovsk. 31– found an overall effectiveness in regularly
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subjects with a record of irregular
Sen Tai Bao vaccination. 35,36 Furthermore, in a cohort
study of more than 1,100 persons whose
In a summary of 5 clinical studies that vaccination deviated from the recommended
investigated the current Chinese vaccine in schedule, a single booster immunization with
children 8–17 years of age (N=616), in adults FSME-IMMUN was administered up to 20
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<60 years of age (N≈5600), and in elderly years after 1, 2, or 3 primary vaccinations.
individuals >60 years of age (N=166), The results of this study demonstrated that,
seropositivity rates (as measured by plaque independent of the interval since last

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