A Phase 2/3 interventional study of FSME-immune in Tick-borne Encephalitis, sponsored by Sormland County Council, Sweden. Completed at 2 sites in 2 countries. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-02-10.
Sponsored by Sormland County Council, Sweden · Phase 2/3, Interventional, and Prevention
The risk for tick borne encephalitis increases in Sweden. Together with an increased awareness of the possibility to acquire protection by vaccination, this has led to an increase in the number of doses of the vaccine distributed in Sweden each year - now being approximately 400.000. The first year, two doses with an interval of 1 month is recommended for the general population, followed by a third dose approximately one year later and an additional booster dose three years after the third.
Preliminary results from a previous study showed a higher percentage protected (=titer at least 10) after 3 doses than after 2 doses (Rombo et al. EUDRA CT 2011 001348-31, unpublished information). In the same study, there were no differences between those who were vaccinated 0+7+21 compared to 0+30+90. The investigators were surprised to find marked differences between 2 and 3 doses also in the younger control group.
The investigators therefore aim to confirm results in a new study and to add a group with a double dose at day 0 and then a single dose at day 30 and 360
The risk for tick borne encephalitis increases in Sweden. Together with an increased awareness of the possibility to acquire protection by vaccination, this has led to an increase in the number of doses of the vaccine distributed in Sweden each year - now being approximately 400.000. The first year, two doses with an interval of 1 month is recommended for the general population, followed by a third dose approximately one year later and an additional booster dose three years after the third.
The manufacturer of Encepur recommended a total of three doses to this age group using the same regimen as with "accelerated vaccination schedule (0+7+21 days). Unfortunately, geometrical mean of titers after 3 doses with the accelerated schedule is not superior to 2 doses given at 0+30 days The manufacturer of FSME-immune instead recommended that serology should be checked one month after the second dose and that a third dose should be given if titers are not sufficient (0+30+60 days). Unfortunately, determinations of titers in a large number of samples put severe strain on logistics and is not feasible in Sweden.
In order to try to improve immunity in the age group 60+ , the Department of Communicable Disease Control and Prevention in Stockholm therefore recommends a third dose two months after the first two doses to the age group 60+ (= 0+30+90 days).
Preliminary results from a previous study showed a higher percentage protected (=titer at least 10) after 3 doses than after 2 doses (Rombo et al. EUDRA CT 2011 001348-31, unpublished information). In the same study, there were no differences between those who were vaccinated 0+7+21 compared to 0+30+90. The investigators were surprised to find marked differences between 2 and 3 doses also in the younger control group
Primary aim: To study whether any differences remain before and one month after an additional dose at the following season Secondary aim: To study whether an additional dose of TBE vaccine 2 months after the second dose will improve protection in an age group 50+.
Primary endpoint: Serum concentration of neutralising antibodies against tick borne encephalitis one month after an additional dose the following year
Secondary endpoints: Serum concentration of neutralising antibodies against tick borne encephalitis one month after two or three doses.
Calculation of power: Depend on whether the aim is to determine differences in geometric mean titers or differences in seroconversion rate. The investigators prefer the former but have not settled for the least difference which would be interesting.
Inclusion critera: Age 50 years or more. Exclusion critera: previous tick borne encephalitis infection. Previously immunized with tick borne encephalitis vaccine. Anaphylactic reac tion to egg protein. Any disease or therapy which might suppress the immune response. Vaccination should be delayed if a participant has fever.
Study design. The investigators intend to give FSME-immune to 4 groups with varying vaccination schedules (see below) 50 participants will be randomized to each Group. A younger age group (50 participants between 18-49 years) will serve as controls and will be given FSME-immune according to standard recommendations (0+30 days)
Days 0 7 21 30 90 360 Vaccine group 1 x x x Vaccine group 2 x x x x Vaccine group 3 x x x x Vaccine group 4 xx x x Controls x x x
Blood samples (10 ml of blood) will be obtained for humoral response as shown below
Days 0 60 120 360 400 Group 1 x x x x x Group 2 x x x x x Group 3 x x x x x Group 4 x x x x x Controls x x x x x
Analyses Samples are analysed for neutralising antibodies at the Swedish institute for Infectious disease control - other options possible.
51 studies on the registry are indexed under Encephalitis, Tick-Borne; 9 are open to participants now.
This study's enrollment of 250 is above the median of 192 across 32 interventional studies indexed under Encephalitis, Tick-Borne.
Browse Encephalitis, Tick-Borne studies →Sormland County Council, Sweden is the lead sponsor of 11 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This group of 50 participants will follow the standard recommendation and will be given TBE vaccine 0.5 ml FSME immune at 0 + 30 days during the first year and an additional dose one year later
Biological: FSME-immune
This group of 50 participants will will be given TBE vaccine 0.5 ml FSME immune at 0 + 7 +21 days during the first year and an additional dose one year later
Biological: FSME-immune
This group of 50 participants will will be given TBE vaccine 0.5 ml FSME immune at 0 + 30 + 90 days during the first year and an additional dose one year later
Biological: FSME-immune
This group of 50 participants in the age group 18-49 years will be given TBE vaccine 0.5 ml FSME immune at 0 +30 days during the first year and an additional dose one year later
Biological: FSME-immune
This group of 50 participants will be given two doses of TBE vaccine 0.5 ml FSME immune at the first day of the study and an additional dose at day 30 as well as one year later
Biological: FSME-immune
0.5 ml im as scheduled in the 5 arms
Serum concentration of neutralising antibodies against TBE one month after two or three doses.
Determination of neutralising antibodies one month after completion of the first years vaccination series
Time frame: 18 months after the first dose
Serum concentration of neutralising antibodies against TBE one month after the dose which will be given a year later
Determination of neutralising antibodies one month after the dose which will be given a year later
Time frame: 18 months after the first dose has been given
This study is completed, as verified in Feb 2021. You cannot join it, but the record below documents what was studied.
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Sormland County Council, Sweden