Search PubMed⌕ Search

Biomedical subjects

H L Bock

Publications and source records attributed to H L Bock.

At least 55 records · Page 3Linked to original sources

Immunogenicity, reactogenicity and consistency of a new, inactivated hepatitis A vaccine--a randomized multicentre study with three consecutive vaccine lots.

We investigated immunogenicity, reactogenicity and consistency of three consecutive lots of an inactivated hepatitis A vaccine in 204 seronegative volunteers. Each volunteer received a total of three doses of vaccine (720 EIU) according to a 0, 1 month primary vaccination schedule with a booster dose given at month 6. Mild, moderate and mostly local side effects were reported in 49.7% after the first and in less than 30% after the third injection. Seroconversion rate after one vaccine dose was as high as 91%. All subjects but one had already seroconverted by 1 month after the second injection, corresponding to a seroconversion rate of 99%. The geometric mean titres (GMT) increased with each dose of vaccine administered. Our results show that this inactivated hepatitis A vaccine is highly immunogenic, safe and well tolerated. Furthermore, there were no significant differences between the three vaccine lots in respect to seroconversion rate, size of antibody titre or reactogenicity.

Antibodies, Viral↗

Vaccination against hepatitis A: comparison of different short-term immunization schedules.

A total of 114 healthy young adults were immunized with hepatitis A vaccine using different vaccination schedules. Individuals received either a single dose (group 1), two doses given simultaneously (group 2), two doses at days 0 and 14 (group 3) or at days 0 and 28 (group 4), or three doses at days 0, 7 and 21 (group 5). Two weeks after a single dose, seroconversion rates between 77 and 85% were achieved (groups 1, 3, 4). All individuals immunized with two doses within two weeks (groups 2, 3, 5) had antibodies to hepatitis A vaccine (anti-HAV positive) by week 3; these participants also showed clearly higher mean anti-HAV values (geometric mean titres, GMTs) at this time than those individuals vaccinated only once. GMTs at week 8 were 560 IU/l in group 5, 236, 339 and 428 IU/l in groups 2-4 and 102 IU/l in group 1. Of participants with anti-HAV at week 8, 82 were again tested 4 months later; all were still seropositive. Ten individuals were tested during the first three weeks at 3-4 day intervals for anti-HAV immunoglobulin M (IgM); specific IgM responses were not detectable before day 10 but were present in eight of 10 vaccinees by day 14.

Adult↗

Reactogenicity and immunogenicity of three different lots of a hepatitis A vaccine.

To study the immunogenicity and reactogenicity of an inactivated hepatitis A vaccine, 204 healthy individuals were randomized into three equal groups, each to receive a different vaccine lot. Each subject received a total of three doses, each of 720 ELISA units of hepatitis A vaccine HM175, according to a 0 and 1 month primary vaccination schedule, with a booster dose given at month 6. Side effects were low and were < 30% after the second injection. All subjects but one had antibodies to hepatitis A virus two months after the first dose of vaccine. At month 6 all vaccinees had seroconverted. There were no differences between the three vaccine lots with respect to side effects, seroconversion rates and geometric mean titre of antibodies. We conclude that the three lots of inactivated hepatitis A vaccine are safe, well tolerated and equally immunogenic.

Adult↗

The efficacy of halofantrine in the treatment of acute malaria in nonimmune travelers.

A multicenter prospective trial was performed to investigate the efficacy and the tolerability of halofantrine in nonimmune patients with malaria imported from areas with drug-resistant falciparum parasites (mainly Africa). Forty-five of the 74 subjects were treated with a one-day regimen (3 x 500 mg) of halofantrine, and the other 29 received the same regimen with an additional treatment on day 7. In the second group, a 100% efficacy rate was demonstrated, but in the group receiving the one-day regimen, four recrudescences were observed in patients with falciparum malaria. Only five mild adverse reactions were seen, which disappeared spontaneously after the end of the treatment. We conclude that halofantrine is highly effective in curing malaria in nonimmune subjects. The treatment scheme for such persons should include an additional treatment on day 7 for nonimmune individuals. This drug was well tolerated in our patients, indicating that halofantrine will be useful in the treatment of multidrug-resistant malaria in nonimmune persons.

Acute Disease↗

Coagulation disorders in experimentally induced acute mouse malaria.

The development of coagulation disorders was studied in murine malaria. Plasmodium vinckei was chosen following an initial experiment because onset and duration of parasitemia were more suitable for hemostasiological studies than in the short-lasting infection, caused by P. berghei. Evaluation of the time courses of hematocrit, platelets, antithrombin (AT) III activity, Factor V activity and parasitemia showed a significant decrease in platelets, hematocrit, Factor V and AT III activity during the course of infection. The obtained data strongly suggest the development of a disseminated intravascular coagulation in mice during the terminal phase of murine malaria.

Animals↗

Humoral immunity against tick-borne encephalitis virus following manifest disease and active immunization.

Humoral immunity against tick-borne encephalitis virus (TBEV) in patients with a well-documented history of naturally acquired tick-borne encephalitis (TBE) was compared with immunity resulting from vaccination in a carefully controlled immunization programme. The vaccination study was performed with a highly purified, inactivated virus particle vaccine and the immune response was followed by tracing the course of IgG antibody formation in an enzyme-linked immunosorbent assay and a neutralization assay. It was shown that this TBE vaccine induced a strong immune response. TBE IgG antibody titres measured after three vaccinations were of the same order of magnitude as those determined in patients recovered from manifest TBE.

Adult↗

A new vaccine against tick-borne encephalitis: initial trial in man including a dose-response study.

A new vaccine against tick-borne encephalitis was investigated in 56 healthy volunteers randomized for five different doses of antigen in a comparative group trial. Good tolerability and high immunogenicity were found using three different antibody test systems. The dose response study revealed that there was a strong relationship between the amount of antigen administered and the antibody response over the range of 0.03-3.0 micrograms antigen per dose.

Adult↗

Antithrombin III substitution affects survival rate in a murine malaria model.

The effect of AT III substitution on survival time was studied in P. vinkei infected mice. One hundred mice were infected, randomly selected and allocated to two groups of 40 animals each on day 13 after infection. One group was placebo treated, the other group received 3 IU AT III daily on days 13 to 19. Comparison of the survival time in the log rank test showed a prolongation of the median survival time (5 versus 9 days, P less than 0.01). It is concluded that AT III might be beneficial in the treatment of severe malaria cases.

Animals↗

Preclinical investigations of the safety, immunogenicity and efficacy of a purified, inactivated tick-borne encephalitis vaccine.

A new tick-borne encephalitis (TBE) vaccine for human use has been developed. TBE virus (TBEV) was propagated in primary chick embryo cells, inactivated by formalin and purified by continuous-flow density gradient centrifugation. The TBE vaccine was tested for innocuity, immunogenicity and protective capacity in a series of laboratory tests. The results indicated that the vaccine is outstandingly well tolerated, highly immunogenic in various laboratory animals, and induces protective immunity in mice. These data suggest that this new vaccine should be studied in clinical trials.

Animals↗

[Not Available].

Explore the source record for details and available documents.

Allergy and Immunology↗

[Is there a paraspecific effect of influenza vaccination?].

In a placebo-controlled pilot trial no paraspecific effects of influenza vaccination were evident. An activation of unspecific immune defence in the sense of "biological immune response modifiers" is discussed in literature as a possible positive side effect of the vaccination. According to the authors the trial shows the progress achieved in the production of vaccines, which is the better tolerance of the vaccine.

Adult↗

Virus safety of a pasteurized antithrombin III concentrate. Preclinical and clinical data.

Blood derived products carry the risk of virus transmission, especially for the hepatitis B virus (HBV), non-A/non-B virus(es) (NANBV) and human immunodeficiency virus (HIV). The precautionary measures for guaranteeing the virus safety of the pasteurized antithrombin III concentrate Kybernin HS/P are described and the efficacy of these measures is demonstrated by in vitro studies and by chimpanzee trials. The inactivation rate is greater than or equal to 10(6.7) for HIV, greater than or equal to 10(6.7) for HBV, and greater than or equal to 10(5.3) for NANBV (Hutchinson Pool). Clinically, virus safety was demonstrated by long-term drug surveillance as well as by both a retrospective and prospective clinical trial. The 13 participants of the prospective study were checked clinically and biochemically according to the standards of the International Committee of Thrombosis and Hemostasis (ICTH). Within an observation period of 12 months, no seroconversion has been detected for HIV or HBV. Neither have any increases in the transaminases occurred which would indicate NANB hepatitis.

Alanine Transaminase↗

Hepatitis B and C in heterosexual patients with various sexually transmitted diseases.

The seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were prospectively assessed in 356 heterosexuals with STDs (sexually transmitted diseases) and compared to a control group of 381 healthy first-time blood donors. Eighty-one of 356 STD patients were anti-HBC positive (22.8%) compared to 14/381 blood donors (3.8%; p less than 0.001). In addition, 18 of the 81 anti-HBC positive STD patients, but none of the controls, were positive for HBSAg (p = 0.06). The prevalence for anti-HCV was also significantly higher in the STD group than in the controls (5.3% vs. 0.5%; p less than 0.001). Among the various STDs syphilis (anti-HBC: 67.5%; anti-HCV: 12.5%) and Chlamydia trachomatis infections (anti-HBc: 20.2%, anti-HCV: 8.1%) had the highest prevalence for both infections. This study provides strong evidence of heterosexual transmission of hepatitis B and C virus infections. Thus, heterosexuals with STDs or multiple partners should be actively vaccinated against hepatitis B.

Adolescent↗

Symptoms and complications of pertussis in adults.

There is increasing evidence that pertussis occurs frequently in adults, but there is limited information on the clinical course of this disease beyond childhood. A household contact study on the efficacy of an acellular pertussis vaccine was used to study the symptoms of pertussis in adults. Among 257 patients with pertussis identified in 121 families during a two-year period in one study center with a low whole-cell pertussis-vaccine uptake, 79 (30.7%) were adults, aged 19-83 years (mean age: 36 years) with a 1:1.8 male to female ratio. Ninety-one percent of the adults suffered from coughing (mean duration: 54 days), and in 80% this cough lasted > or = 21 days. Whoops were rare (8%), whereas cough followed by vomiting and/or choking (53%) and cough disturbing sleep (52%) were common. This is the first report to describe sweating attacks as symptom of pertussis (14%). Pharyngeal symptoms (37%), influenza-like symptoms (30%), sneezing attacks (22%), hoarseness (18%), sinus pain (16%) and headaches (14%) were also observed. Various complications were seen in 23% of the patients. In order to minimize the spread of the organism, microbiological diagnostics should be vigorously applied to all symptomatic contacts of a patient with pertussis but also to all patients with long lasting cough-irrespective of age.

Adult↗

Synergy of antithrombin III concentrate and antivenom in preventing coagulopathy in a rat model of Malayan pit viper envenoming.

The effects of unrefined equine antivenom and antithrombin III (AT-III) concentrate on the coagulopathy induced by systemic envenomation by Malayan pit viper (Calloselasma rhodostoma; MPV) venom were investigated in a rat model. 37 rats received an intramuscular injection of MPV venom and serial blood samples were taken from the femoral vein for simple whole blood clotting tests and measurement of AT-III activity. 30 min after venom injection, treatment (antivenom, AT-III or both) was given intravenously. 6 rats were untreated and all developed uncoagulable blood and AT-III depletion 90-210 (median 180) min after venom injection. A combination of high dose AT-III concentrate (0.5 units/g) and antivenom (20 micrograms/g) prevented abnormal clotting (P less than 0.001), whereas AT-III alone, antivenom alone, or a combination of low dose AT-III (0.25 units/g) and antivenom did not (P less than 0.05). These results suggest that the coagulation abnormality in MPV envenomation is secondary to activation of the coagulation cascade at several levels, and that treatment with antivenom alone may not be sufficient to reverse or prevent this phenomenon.

Animals↗

Does the concurrent administration of an inactivated hepatitis A vaccine influence the immune response to other travelers vaccines?

BACKGROUND: Travelers seeking protection from hepatitis A also often need protection against other infections, prevalent at their destinations. METHODS: A total of 396 volunteers received not only a hepatitis A vaccine but also either a vaccine against polio, hepatitis B, diphtheria, tetanus, yellow fever, Japanese encephalitis, typhoid fever or rabies according to their individual needs. We investigated the potential influence of the hepatitis A vaccination on the immune response to the other travelers vaccines that were administered concurrently. RESULTS: With seroprotection rates of 100% for yellow fever, Japanese encephalitis and rabies immunization and tetanus boosters our data demonstrate that the concurrent administration of hepatitis A vaccine does not compromise the immune response of these vaccines. Also for oral typhoid, hepatitis B and diphtheria vaccination we did not detect a negative influence of concurrent hepatitis A vaccine administration as compared with respective vaccinations when given alone. Prior to vaccination, more than one third of our subjects lacked protective antibody levels against diphtheria and only 44% of initially seronegative travelers seroconverted to an anti-diphtheria titer > or = 0.01 mIU/mL, supporting a need for an additional dose. Furthermore, only two thirds of the vaccinees tested prior to vaccination were protected against polio type 3, and the seroconversion rate following the administration of oral polio vaccine, was lower for viral type 3 (80%), as has been previously demonstrated in settings without concurrent other vaccinations. CONCLUSION: No negative effect of concurrent travelers vaccinations on the immune response of a hepatitis A vaccine has been detected in a previous report, and, likewise our data suggest no impairment of the antibody response of these travelers vaccines by the concurrent administration of the hepatitis A vaccine.

Adolescent↗