Efficacy of inactivated split-virus influenza vaccine against culture-confirmed influenza in healthy adults: a prospective, randomized, placebo-controlled trial.

BACKGROUND: A new trivalent inactivated split-virus influenza vaccine (TIV) was recently introduced in the United States. We assessed the efficacy of TIV against culture-confirmed influenza A and/or B. METHODS: In this double-blind trial conducted from September 2006 to May 2007 in the Czech Republic and Finland, participants aged 18-64 years were randomized to receive 1 dose of TIV (n = 5103) or placebo (n = 2549). Influenza-like illnesses (ILI) (defined as at least 1 systemic symptom [fever {oral temperature, > or = 37.8 degrees C} and/or myalgia] and at least 1 respiratory symptom [cough and/or sore throat]) were identified by both active (biweekly phone contact) and passive surveillance. Nasal and throat swab specimens were collected for viral culture. RESULTS: The attack rate for culture-confirmed ILI was 3.2% in the placebo group, with most strains identified as influenza A (all except 1 were H3N2) matching the vaccine strain. There were 6 cases of influenza B, all of which were of a different lineage (Yamagata) than the vaccine strain. Vaccine efficacy against culture-confirmed influenza A and/or B due to strains antigenically matched to the vaccine was 66.9% (95% confidence interval [CI], 51.9%-77.4%; P < .001) and to any strain was 61.6% (95% CI, 46.0%-72.8%; P < .001). CONCLUSION: TIV is efficacious against culture-confirmed influenza in healthy adults. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00363870.

Challenge of conducting a placebo-controlled randomized efficacy study for influenza vaccine in a season with low attack rate and a mismatched vaccine B strain: a concrete example.

BACKGROUND: Our 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. METHODS: 6203 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 > or = 45%. Cases of influenza like illness (defined as fever (oral temperature > or =37.8 degrees 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. RESULTS: TIV 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%). CONCLUSION: Due 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 REGISTRATION: Clinical trial registery: NCT00197223.

TBE infection in an incomplete immunized person at-risk who lives in a high-endemic area--impact on current recommendations for immunization of high-risk groups.

This is a case report on a 50-year-old patient, working as a forest guard in a high-endemic region. The subject was immunized with two doses of FSME Immun 0.5 Baxter vaccine (with a time interval of 18 days between the two doses). Approx. two months after the second vaccination the subject developed symptoms of Tick-borne encephalitis. Clinical course and laboratory findings confirmed diagnosis of meningo-encephalo-myelitis with moderate sequelae 1 year after infection. Based on this clinical case we recommend in subjects with an accumulation of risk factors, as age older than 50 years who are living and working in high-endemic areas, a vaccination with conventional schedule (at least two doses applied at 0 to 1-3 months) ahead of TBE season or a rapid schedule with three doses (0, 7 and 21 days) of vaccine.

Motion-onset and pattern-reversal visual evoked potentials in diagnostics of neuroborreliosis.

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.

[Malaria-an unusual cause of fever in the infant.].

Malaria is the fourth most frequent cause of death in African children. Connected with perinatal diseases as well as gastrointestinal and respiratory infections malaria has been still a serious health problem of that region. Occurrence of tropical malaria in infants reported in European countries is relatively rare. Not only from that reason, the assesment of diagnosis in children under one year of age seems to be obviously more difficult. The authors report the malaria in five-month-old infant from Cameroon who became ill during his stay in the Czech Republic. Non-specific symptoms, high level of parasitemia and impairment of blood coagulation were the main features of the emergent infection. On conclusion, the lack of suitable forms of childrens antimalarial drugs both for profylaxis and treatment is mentioned.

Potency requirements of rabies vaccines administered intradermally using the Thai Red Cross regimen: investigation of the immunogenicity of serially diluted purified chick embryo cell rabies vaccine.

To determine the minimum vaccine potency per intradermal dose required to elicit an adequate immune response using the Thai Red Cross (TRC) regimen (2-2-2-0-1-1), healthy volunteers received 0.1 mL volumes of PCECV containing decreasing amounts of antigen. Subjects also received HRIG to evaluate potential interference with antibody production. Results indicated that when each 0.1 mL intradermal dose of PCECV contained antigen corresponding to 0.32 IU per intramuscular dose, every subject had titers above 0.5 IU/mL by day 14. These results confirm that the current World Health Organization (WHO) recommendations for vaccine potency (2.5 IU per intramuscular dose) are sufficient for use in the Thai Red Cross intradermal regimen.

Diagnosis of Lyme borreliosis using enzyme immunoanalysis.

BACKGROUND: Antiborrelia antibodies in Lyme borreliosis (LB) are mostly detected by enzyme immunoassay (EIA), confirmed by immunoblot (the "two-step system"). In indicated cases, direct evidence of Borrelia burgdorferi is obtained with the PCR method, electron microscopy and cultivation. The "one-step system" of testing for IgM and IgG antibodies in LB is economically preferably, but it requires an EIA kit with more than 90% sensitivity and specificity. MATERIAL/METHODS: 90 blood samples were collected, 54 from patients with clinically defined LB and 36 samples from individuals free of LB. IgM and IgG antibodies against Borrelia burgdorferi were detected in parallel with five different EIA kits from various producers. The results were verified clinically in all cases, in disputable cases with additional immunoblot (BAG-Med), and analyzed statistically. RESULTS: Specificity and sensitivity were calculated from the measured values, and diagnostic efficiency was determined for each EIA kit. EIA kits for antiborrelia antibody assay with high specificity have low sensitivity and vice versa. In 9 samples from patients with clinical diagnoses (multiple sclerosis, Parkinson disease, epilepsy, rheumatoid arthritis) we found false positives in EIA and WB tests. CONCLUSIONS: The best results for a "one-step system" of examinations for antiborrelia antibodies were obtained with the Abbot and Euroimmun EIA kits in our set. A "two-step system" of serological examination could be composed from the basic IgM and IgG examination with a high sensitivity EIA kit (Viroimmun, Test-Line) followed with confirmation of positives by specific immunoblot.

[Clinical manifestations and treatment of Lyme disease]. / Klinické projevy a lécba lymské boreliózy.

Survey of criteria necessary to establish the diagnosis of Lyme disease according to its definitions by various organizations and institutions in the USA and Europe (European Union Concerted Action on Lyme Borreliosis, Centers for Disease Control and Prevention, The International Lyme and Associated Diseases Society). In the discussion the authors present other possible clinical manifestations connected with the involvement of various organs. In the second part of their paper they describe patterns of therapy for individual forms of Lyme disease in Europe and the USA and their differences.