Immunogenicity of a booster vaccination against tick-borne encephalitis

• Main Authors: Lucija Beškovnik, Tatjana Frelih, Tatjana Avšič Županc, Miša Korva, Alenka Trop Skaza
• Format: Article
• Language: English
• Published: Slovenian Medical Association 2016-10-01
• Series: Zdravniški Vestnik
• Subjects: tick-borne encephalitis – TBE; epidemiology; vaccination; serological response; flavivirus.
• Online Access: http://vestnik.szd.si/index.php/ZdravVest/article/view/1487

<p><strong>Abstract</strong></p><p><strong>Background:</strong> Tick-borne encephalitis is endemic in Slovenia, but still less than 10 % of people are regularly vaccinated. The proportion of vaccinated individuals was significantly influenced by obligatory vaccination for all Slovenian military conscripts between 1993 and 2003.</p><p><strong>Methods:</strong> Our study includes 73 men from the Celje region, who were vaccinated with three doses of vaccine against tick-borne meningoencephalitis FSME-Immun® (Baxter), but afterwards they stopped the vaccination for a period of 8 to 16 years. Participating men were serologically tested before and after the first booster dose. We used the enzyme immunoassay Enzygnost^®.</p><p><strong>Results:</strong> The result of the analysis was, that with most of the participants the value of titer of antibodies before receiving revaccination was protective (n=67; 91,8 %), while after receiving a booster dose, the protective value was exceeded for all participants who have submitted a second blood sample (n=69; 94,5 %). Geometric mean concentration before the booster dose was 56 U/ml and 314 U/ml after the booster dose.</p><p><strong>Conclusions:</strong> Our study confirmed the long-term protection after primary vaccination with three doses against tick-borne encephalitis with men younger than 50 years, by using enzyme immunoassay. The results support the careful consideration of currently recommended revaccination interval.</p>