BackgroundOur aim was to determine the efficacy of a trivalent inactivated split virus influenza vaccine (TIV) against culture-confirmed influenza A and/or B in adults 18 to 64 years of age during the 2005/2006 season in the Czech Republic.Methods6203 subjects were randomized to receive TIV (N = 4137) or placebo (N = 2066). The sample size was based on an assumed attack rate of 4% which provided 90% power to reject the hypothesis that vaccine efficacy (VE) was ≥ 45%. Cases of influenza like illness (defined as fever (oral temperature ≥37.8°C) plus cough and/or sore throat) were identified both by active (biweekly phone contact) and passive (self reporting) surveillance and nasal and throat swabs were collected from subjects for viral culture.ResultsTIV was well tolerated and induced a good immune response. The 2005/2006 influenza season was exceptionally mild in the study area, as it was throughout Europe, and only 46 culture-confirmed cases were found in the study cohort (10 influenza A and 36 influenza B). Furthermore among the B isolates, 35 were identified as B/Hong Kong 330/2001-like (B/Victoria/2/87 lineage) which is antigenically unrelated to the vaccine B strain (B/Yamagata/16/88 lineage). The attack rate in the vaccine group (0.7%) was not statistically significantly different from the attack rate in the placebo group (0.9%).ConclusionDue to the atypical nature of the influenza season during this study we were unable to assess TIV efficacy. This experience illustrates the challenge of conducting a prospective influenza vaccine efficacy trial during a single season when influenza attack rates and drift in circulating strains or B virus lineage match can be difficult to estimate in advance.Trial RegistrationClinical trial registery: NCT00197223.

ClinicalTrials.gov identifier: NCT00363870.

Neuroborreliosis is a form of borreliosis that affects the central and/or peripheral nervous system. Although it can mimic neurologic and ophthalmologic disorders such as multiple sclerosis and optic neuritis, visual evoked potential (VEP) examination is usually not used in neuroborreliosis diagnostics. Combined VEP testing (pattern-reversal VEPs and VEPs produced in response to linear and radial motion) was performed in 81 patients with neuroborreliosis verified by laboratory results (positive polymerase chain reaction or intrathecal antibodies production). Thirty-four patients reported diplopia or blurred vision related to borreliosis. In 33 (40%) patients the VEPs were delayed: motion-onset VEPs were pathologic in 22 (27%) patients, reversal VEPs in 5 (6%) patients, and both VEP types in 6 (7%) patients. The findings suggest that VEP testing (especially the motion-onset VEP testing) can confirm CNS involvement. Much higher sensitivity of motion-onset VEPs in comparison with reversal VEPs can result from rather selective (earlier) involvement of the magnocellular system or the dorsal stream of the visual pathway.

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