Analysis of post-vaccination adverse reactions in patients vaccinated against tick-borne encephalitis with EnceVir vaccine during tick-borne encephalitis epidemiological season of2010-2011
The analysis of the post-vaccination fever, which appeared for the first time during tick-borne encephalitis epidemiological season after vaccination against tick-borne encephalitis with EnceVir vaccine showed, that the reactions were transient, took place on the day of vaccination and terminated within 1-3 days after vaccination. Their frequency in some regions exceeded the limits, specified in the prescribing information. Analysis of the reactions characteristics, quality control of 28 batches of the vaccine, and analysis for total protein and viral antigen content demonstrated that a possible reason for vaccinal fever was insufficient purification and substandard dilution of intermediate concentrate of TBE vaccine series produced in 2010-2011, which led to high concentration of viral antigen in the preparation.