Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional
Official Title: Humoral Response to TBE Vaccine in Elderly (50+ Year Olds) After Changed Dosage Intervals/Number of Doses?
Brief Summary:
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 EUDRA CT 2011 001348-31, unpublished information).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