Page 449 - TBE_Book_V2_2019

Chapter 14: Prevention

8
However, this has not yet been adequately adults and 1,598 children). Overall
studied in humans. For instance, TBE seroconversion rates exceeding 87% were
vaccination has been shown to enhance the observed. Studies conducted by the
immune response to an inactivated JEV respective manufacturers report sero-
7
vaccine, but even though cross-reactive conversion rates in the range of 92%–100%
antibodies have been described, there is no for Encepur and FSME-IMMUN, as measur-
evidence of actual cross-protection between ed by a commercial enzyme-linked
JEV and TBE vaccines. immunosorbent assay (ELISA) or neutraliza-
tion test (NT), with seroconversion being
For both European TBE vaccines, there are no defined as NT ≥1:10, or according to the
data on their use during pregnancy and recommendations of the ELISA manu-
lactation. As with all other inactivated facturer. 9–12
vaccines, an application during pregnancy
may be considered after carefully weighing FSME-IMMUN
risk and benefit.
The clinical development program for FSME-
Vaccine stability and storage IMMUN included 13 studies that investigated
the immunogenicity and safety of the vaccine
FSME-IMMUN is available as a pre-filled in approximately 5,180 adults and 6,430
syringe without needle. The vaccine must be children. An additional 4 studies on FSME-
refrigerated at 2°C to 8°C. The shelf life is 30 IMMUN were identified after review and
9
months. Encepur is available as a pre-filled analysis of published literature. The sero-
syringe with and without needle and must be conversion rate in adults 16 to 65 years of age,
stored at the same temperature (between 2°C vaccinated according to the conventional
and 8°C). The shelf life is 24 months. TBE- schedule, was 97% after the second dose and
Moscow vaccine has a shelf life of 24 months ranged between 99.5% and 100% after the
9
and EnceVir of 36 months, both with the third dose, as measured by ELISA and/or NT.
same temperature requirements as the When the rapid immunization schedule (Table
European vaccines. The currently licensed 2) was used, seroconversion rates in NT after
Chinese vaccine has a shelf life of 21 months. the second vaccination were 98.0% and 89.9%
in adults younger or older than age 50,

respectively, and 100% and 99.3% in those 2
age groups after the third vaccination,
Vaccine immunogenicity respectively. Two pediatric studies (a dose-
finding study with more than 400 children
No clinical studies with efficacy endpoints who received the later licensed pediatric dose
have been conducted on any of the licensed and a large safety study with an immuno-
TBE vaccines. These vaccines have been genicity subset that included approximately
registered on the basis of immunogenicity 370 children, all between the ages of 1 and 15
and safety studies, which consistently show years) found seroconversion rates (ELISA) of
strong immune responses after primary 96% to 100% (depending on the age sub-
vaccination with the vaccine. A Cochrane group) after the second vaccination and
Collaboration review published in 2009 almost 100% in all age subgroups after the
summarized 11 randomized clinical trials (10 third vaccination.
13
publications), conducted with 3 different
TBE vaccines(IPVE, FSME-IMMUN, and
Encepur) and involving 8,184 subjects (6,586

444
451