Jiri Beran1, Maria Lattanzi2, Fang Xie3, Luca Moraschini4, Ilaria Galgani5. 1. Vaccination and Travel Medicine Centre, Tylovo nábřeží 418/6, 500 02 Hradec Králové, Czech Republic; Department for Tropical, Travel Medicine and Immunization, Institute for Postgraduate Medical Education in Prague, Ruská 2412/85, 100 00 Prague 10, Czech Republic. Electronic address: jiri.beran@vakcinace.cz. 2. GSK, Via Fiorentina 1, 53100 Siena, Italy. Electronic address: maria.x.lattanzi@gsk.com. 3. GSK Vaccines, 14200 Shady Grove Rd, Rockville, MD 20850, USA. Electronic address: fang.z.xie@gsk.com. 4. GSK, Via Fiorentina 1, 53100 Siena, Italy. Electronic address: luca.x.moraschini@gsk.com. 5. GSK, Via Fiorentina 1, 53100 Siena, Italy. Electronic address: ilaria.x.galgani@gsk.com.
Abstract
BACKGROUND: Tick borne encephalitis (TBE) endemic zones are expanding. We previously evaluated long term persistence of antibody 5 years after the first booster immunization following different primary immunization schedules with the polygeline-free inactivated TBE vaccine (TBEvac) in adults and adolescents. Here, we report anti-TBE virus (TBEV) antibody persistence from 6 to 10 years post-booster administration. METHODS: This was a phase IV, open-label, single-center, second extension study (NCT01562444), conducted in Czechia. Healthy adults and adolescents ≥12 years who had received 3 different primary vaccination schedules (rapid, conventional and accelerated conventional) in the parent study and a booster dose before (12-18 months post-primary series completion) or at the beginning (3 years post-primary series completion) of the first extension study were screened and enrolled in this study. Blood samples were collected yearly and anti-TBEV antibody response was evaluated by neutralizing test (NT) antibody assays. Analysis was performed overall and per age strata: 15-49 years, ≥50 years, and ≥60 years. RESULTS: Of 206 screened individuals, 191 completed the study. Overall, 90-100% of participants in the all-screened set and ≥97% in the per-protocol set had the clinically meaningful threshold of protection (NT titers ≥10) across all timepoints, regardless of the primary vaccination schedule. Overall, antibody geometric mean titers (GMTs) varied from 134 to 343 in the all-screened set. Older age groups showed overall lower GMTs, although GMTs remained higher than NT titers ≥10 up to year 10 in all groups. CONCLUSION: This study showed long-term persistence of anti-TBEV NT antibodies for up to 10 years after the first booster dose of TBEvac in all age groups, regardless of the primary vaccination schedule.
BACKGROUND:Tick borne encephalitis (TBE) endemic zones are expanding. We previously evaluated long term persistence of antibody 5 years after the first booster immunization following different primary immunization schedules with the polygeline-free inactivated TBE vaccine (TBEvac) in adults and adolescents. Here, we report anti-TBE virus (TBEV) antibody persistence from 6 to 10 years post-booster administration. METHODS: This was a phase IV, open-label, single-center, second extension study (NCT01562444), conducted in Czechia. Healthy adults and adolescents ≥12 years who had received 3 different primary vaccination schedules (rapid, conventional and accelerated conventional) in the parent study and a booster dose before (12-18 months post-primary series completion) or at the beginning (3 years post-primary series completion) of the first extension study were screened and enrolled in this study. Blood samples were collected yearly and anti-TBEV antibody response was evaluated by neutralizing test (NT) antibody assays. Analysis was performed overall and per age strata: 15-49 years, ≥50 years, and ≥60 years. RESULTS: Of 206 screened individuals, 191 completed the study. Overall, 90-100% of participants in the all-screened set and ≥97% in the per-protocol set had the clinically meaningful threshold of protection (NT titers ≥10) across all timepoints, regardless of the primary vaccination schedule. Overall, antibody geometric mean titers (GMTs) varied from 134 to 343 in the all-screened set. Older age groups showed overall lower GMTs, although GMTs remained higher than NT titers ≥10 up to year 10 in all groups. CONCLUSION: This study showed long-term persistence of anti-TBEV NT antibodies for up to 10 years after the first booster dose of TBEvac in all age groups, regardless of the primary vaccination schedule.
Authors: Monique Petry; Martin Palus; Eva Leitzen; Johanna Gracia Mitterreiter; Bei Huang; Andrea Kröger; Georges M G M Verjans; Wolfgang Baumgärtner; Guus F Rimmelzwaan; Daniel Růžek; Albert Osterhaus; Chittappen Kandiyil Prajeeth Journal: Vaccines (Basel) Date: 2021-02-26