Abstract
Backgrounds: Tick-borne Encephalitis (TBE) is an infection by the Tick-borne Encephalitis virus (TBEV)
with central nervous system signs and/or symptoms. TBE is endemic in Latvia and elsewhere in Europe
and Asia. In Latvia, pediatric TBE vaccines, including FSME-IMMUN Junior (FSME-Jr), are
recommended, and partially government-reimbursed, for children 1-15 years-of-age but TBE vaccine
effectiveness (VE) in children has not been reported.
Methods: Rīga Stradinš University conducted nationwide population-based surveillance for TBE cases in
collaboration with the Centre for Disease Prevention and Control, the National Reference Laboratory, and
15 hospitals. Serum and cerebrospinal fluid were tested by ELISA for TBEV-specific IgG and IgM
antibodies. After informed consent, patient interviews and medical record review were used to determine
the proportion of TBE cases FSME-Jr fully-vaccinated (on-schedule receipt of the three-dose primary
series) (PCV). General population surveys conducted by IPSOS in 2019 and 2020 were used to
determine the proportion of the population FSME-Jr fully-vaccinated (PPV). FSME-Jr VE (with 95%
confidence interval) was estimated using the screening method (VE=1−((PCV/(1−PCV)/(PPV/(1−PPV)).
Results: From 2018-2020, surveillance identified 36 TBE cases in children 1-15 years-of-age; all cases
were hospitalized, 5 (14%) for >12 days. TBE incidence in children 1-15 years-of-age was 4.0/100,000
population per year. Of the TBE cases, 34 (94%) were unvaccinated, 1 (3%) was FSME-Jr fullyvaccinated, and 1 (3%%) was partially-vaccinated. Among children 1-15 years-of-age with a reported
vaccination status in the general population, 44% were unvaccinated, 13% were FSME-Jr fullyvaccinated, and 43% were partially-vaccinated or received another TBE vaccine. VE of FSME-Jr was
90.1% (27.3-98.6) against TBE.
Conclusions/Learning Points: FSME-Jr was highly effective in preventing TBE in children 1-15 yearsof-age in Latvia. Increasing FSME-Jr uptake and adherence to the recommended three-dose schedule is
essential to maximize FSME-Jr public health impact.
with central nervous system signs and/or symptoms. TBE is endemic in Latvia and elsewhere in Europe
and Asia. In Latvia, pediatric TBE vaccines, including FSME-IMMUN Junior (FSME-Jr), are
recommended, and partially government-reimbursed, for children 1-15 years-of-age but TBE vaccine
effectiveness (VE) in children has not been reported.
Methods: Rīga Stradinš University conducted nationwide population-based surveillance for TBE cases in
collaboration with the Centre for Disease Prevention and Control, the National Reference Laboratory, and
15 hospitals. Serum and cerebrospinal fluid were tested by ELISA for TBEV-specific IgG and IgM
antibodies. After informed consent, patient interviews and medical record review were used to determine
the proportion of TBE cases FSME-Jr fully-vaccinated (on-schedule receipt of the three-dose primary
series) (PCV). General population surveys conducted by IPSOS in 2019 and 2020 were used to
determine the proportion of the population FSME-Jr fully-vaccinated (PPV). FSME-Jr VE (with 95%
confidence interval) was estimated using the screening method (VE=1−((PCV/(1−PCV)/(PPV/(1−PPV)).
Results: From 2018-2020, surveillance identified 36 TBE cases in children 1-15 years-of-age; all cases
were hospitalized, 5 (14%) for >12 days. TBE incidence in children 1-15 years-of-age was 4.0/100,000
population per year. Of the TBE cases, 34 (94%) were unvaccinated, 1 (3%) was FSME-Jr fullyvaccinated, and 1 (3%%) was partially-vaccinated. Among children 1-15 years-of-age with a reported
vaccination status in the general population, 44% were unvaccinated, 13% were FSME-Jr fullyvaccinated, and 43% were partially-vaccinated or received another TBE vaccine. VE of FSME-Jr was
90.1% (27.3-98.6) against TBE.
Conclusions/Learning Points: FSME-Jr was highly effective in preventing TBE in children 1-15 yearsof-age in Latvia. Increasing FSME-Jr uptake and adherence to the recommended three-dose schedule is
essential to maximize FSME-Jr public health impact.
| Original language | English |
|---|---|
| Pages | 622 |
| Publication status | Published - 2023 |
| Event | 41st Annual Meeting of the European Society for Paediatric Infectious Diseases (ESPID - Online, Lisbon, Portugal Duration: 8 May 2023 → 12 May 2023 Conference number: 41 https://espidmeeting.org/?utm_source=google&utm_medium=search&utm_campaign=earlyregistration&gclid=EAIaIQobChMIx8m4j46s_QIVByIYCh26qQWvEAAYASAAEgJj-vD_BwE |
Conference
| Conference | 41st Annual Meeting of the European Society for Paediatric Infectious Diseases (ESPID |
|---|---|
| Country/Territory | Portugal |
| City | Lisbon |
| Period | 8/05/23 → 12/05/23 |
| Internet address |
Field of Science*
- 3.2 Clinical medicine
Publication Type*
- 3.4. Other publications in conference proceedings (including local)
