PubMed Health⌕ Search

Biomedical subjects

F Ambrosch

Publications and source records attributed to F Ambrosch.

At least 37 records · Page 2Linked to original sources
PubMed1990

Safety and immunogenicity of an inactivated hepatitis A candidate vaccine in healthy adult volunteers.

The reactogenicity and immunogenicity of a formaldehyde-inactivated hepatitis A vaccine have been investigated. Three different dose levels of vaccine (180, 360 and 720 ELISA units) were administered to healthy volunteers according to a 0, 1, 2 and 12 month schedule. The vaccine was safe and well tolerated. Reactions observed following vaccination were essentially mild and were not dependent upon the quantity of antigen administered. All subjects had measurable titres of anti-HAV antibodies after the full vaccination course; the immune response to the vaccine was dose-related. Antibody titres in vaccinees at month 13 were between 60- and 190-fold higher than those observed in a group of subjects given anti-HAV immunoglobulin.

Adolescent↗
PubMed1988

Tolerability and immunogenicity of a polyvalent Pseudomonas aeruginosa extract vaccine in human volunteers.

A polyvalent 16 serotype Pseudomonas extract vaccine was administered to normal volunteers to ascertain tolerability, immunogenicity and immunisation schedule. Four groups of nine volunteers were immunised with 0.8 X 10(9) bacterial equivalents (BE), 1.2 X 10(9) BE, 1.6 X 10(9) BE or placebo, respectively, on days 0, 14 and 21. A further six volunteers were immunised with 1.6 X 10(9) BE on days 0 and 28. Tolerability was excellent, slight side effects were unrelated to vaccine concentration and decreased with the number of injections. All concentrations of vaccine gave a significantly increased titre 14 days after the first immunisation. Reimmunisation did not increase the titre, which reached a plateau at day 14. Individuals with high pre-immunisation-titres produced very high post-immunisation-titres with a conversion factor of 6.5 whilst those with low pre-immunisation-titres had a higher conversion factor of 13 but produced lower final titres. ELISA titre did not always correlate with biological activity (mouse protection assay) suggesting that effective protective antibodies are only part of the total specific antibody measured by ELISA with the polyvalent whole-cell vaccine antigen.

Adult↗
PubMed1988

Lack of induction of IgE and IgG antibodies to yeast in humans immunized with recombinant hepatitis B vaccines.

Yeast-derived hepatitis B vaccines (partially purified or highly purified) at different dosages and a plasma-derived hepatitis B vaccine (control) were injected into 50 young volunteers 3 times at monthly intervals. Before and 4 weeks after this series of immunizations, blood samples were drawn and tested for presence of IgE and IgG antibodies against yeast antigens. No rise in IgE antibodies against Saccharomyces cerevisiae antigens nor in IgG antibodies against Candida albicans antigens was found. Together with former clinical results this underlines the experience that type I and type III reactions against putative yeast contaminants apparently play no major role after immunization with recombinant hepatitis B vaccines.

Adult↗
PubMed1987

[Travel diarrhea: attempt at a clinical-epidemiologic evaluation].

Traveller's diarrhea is the most common tourist's disease in the tropics. Therefore epidemiological data for the evaluation of factors influencing the attack rates and the severity of the disease are being required. This paper deals with the data of 1058 Austrian tourists travelling to warm climate countries. 47.3% of all travellers suffered from an episode of traveller's diarrhea during their stay. However, it could be evaluated that besides the destination seasonal influences were very important. Factors like individual hygiene and accommodation did not influence the attack rates. Age and environmental conditions, however, did partially influence the frequency of diarrhea. Furthermore, additional symptoms were interpreted and it could be seen that suspected heterogenicity of etiology leads to a similar pattern of clinical symptoms. Clinical evaluation proves that traveller's diarrhea is commonly not severe, but due to the incidence and duration of the disease it is a major health problem in modern tourism.

Cross-Cultural Comparison↗
PubMed1987

Multicentre dose range study of a yeast-derived hepatitis B vaccine.

Healthy young adult volunteers, 778 in number, without HBV markers were randomly distributed into groups and administered different lots of a yeast-derived hepatitis B vaccine (YDV) at different dose levels or a commercial plasma-derived vaccine (PDV), according to a 0, 1, 2, 12-month vaccination schedule. The YDV proved to be safe and well tolerated, even when partly purified lots were given. Reactions were mild and transient, comparable to those observed after PDV. One month after three YDV doses, 0-7% of subjects overall had failed to seroconvert; all those evaluated one month after the booster dose had seroconverted. No significant difference was found between the two vaccine types as far as seroconversion rates were concerned. Geometric mean anti-HBs levels following three vaccine doses were higher in seroconverters of the PDV groups. However, a booster dose of YDV resulted in high anti-HBs levels in all groups varying from 11,474 to 51,404 IU l-1 (purified YDV lot), 4915 to 18,832 IU l-1 (partly purified YDV lots) and 11,008 to 15,805 IU l-1 (PDV lots). Of seroconverters to the purified lots of YDV 93% attained 1000 IU l-1 after the booster dose, thus ensuring protection for a number of years. Dose-response studies provided a basis for the selection of 20 micrograms of highly purified YDV as the standard dose.

Adult↗
PubMed1987

Reactogenicity and immunogenicity of different lots of a yeast-derived hepatitis B vaccine.

Several lots of a yeast-derived hepatitis B vaccine at different doses and a 20 micrograms dose of plasma-derived vaccine were tested in young healthy adults and compared with respect to risk of hypersensitivity reactions, reactogenicity, and immunogenicity. No signs of hypersensitivity either pre-existing or vaccine-induced were observed. Reactogenicity was low and similar in all vaccine groups. It was not dose related and unaffected by the number of injections. Immunogenicity was evaluated for a 0, 1, 2, and 12 month vaccination schedule. Seroconversion rates (greater than or equal to 10 IU/l) were not significantly different between the purified yeast- and plasma-derived vaccines one month after the second vaccination whereas the percentage of seroconversion was slightly lower in the groups receiving only partly purified recombinant vaccines. Although geometric mean titres induced by the plasma-derived vaccine were somewhat higher after the first months, the antibody titres induced by the recombinant vaccine were at least as high as those elicited by a plasma-derived vaccine following the booster dose.

Antigens↗
PubMed1987

Persistence of vaccine-induced antibodies to hepatitis B surface antigen and the need for booster vaccination in adult subjects.

Protection against hepatitis B virus infection can be achieved by the induction of neutralizing antibodies against the hepatitis B surface antigen (HBsAg). An antibody concentration of 10 IU/l, as measured by radioimmunoassay, is considered to be protective. HBsAg can be produced either from the plasma of chronic carriers or by DNA recombinant technology in yeast cells. Plasma- and yeast-derived vaccines have been compared in several studies and their immunological properties were found to be similar, including the persistence of antibodies induced by either type of vaccine. Finally, yeast-derived hepatitis B vaccine can boost anti-HBs responses initially elicited by either plasma- or yeast-derived vaccine equally and effectively. In order to maintain protective immunity after hepatitis B vaccination, antibody determination and, if necessary, booster vaccination should be performed, particularly in high-risk persons.

Adult↗
PubMed1986

A controlled trial for evaluating two live attenuated mumps-measles vaccines (Urabe Am 9-Schwarz and Jeryl Lynn-Moraten) in young children.

A prospective, randomised clinical trial was conducted to evaluate the efficacy of two live attenuated mumps-measles vaccines, the Urabe Am 9-Schwarz and the Jeryl Lynn-Moraten vaccine, in 400 young children aged 9 months-4.5 years (median 13.4 months). Antibody responses to both vaccine components were measured by the enzyme-linked immunosorbent assay (ELISA); 96.9% of the seronegative children who received the Urabe Am 9-Schwarz vaccine showed satisfactory mumps antibody responses compared to 90% of the Jeryl Lynn-Moraten vaccine recipients (P less than .01). Similar proportions of both groups, 98.5% and 96.8%, respectively, developed measles virus specific antibodies. Both vaccines were equally well tolerated and clinically acceptable.

Antibody Formation↗
PubMed1986

Studies on the influence of BCG vaccination on infantile leukemia.

In the situation of low and decreasing risk of tuberculosis the possible non specific effect of BCG vaccination against leukemia becomes more and more important. To answer this question several studies using epidemiological and clinical data of children up to 5 years were performed in Austria. The following parameters which might be influenced by a possible protective effect of BCG vaccination were checked: leukemia mortality, case fatality, age of manifestation, frequency of different kinds of leukemia and the distribution of tuberculin reactions in leukemic and non leukemic children. All these parameters showed significant differences between vaccinated and non vaccinated leukemic and non leukemic children respectively making a protective effect of BCG vaccination against leukemia highly probable.

Austria↗
PubMed1984

[Split tetanus vaccine. Studies on its efficacy and tolerance as compared to adsorbed vaccine].

A tetanus split vaccine consisting of the purified C fragment of tetanus toxin was compared with normal adsorbed toxoid vaccine with respect to local reactions and immunogenicity. Altogether, 200 volunteers with primary vaccination against tetanus were vaccinated. Local reactions were studied in 170 persons, the immune response in 87. Immunogenicity, expressed as mean conversion factor, was identical for both groups. Local reactions, including frequency, duration and intensity of symptoms, were reduced by 60% in the subjects given split vaccine. In both groups a positive correlation between preimmunization antibody titer and the mean extent of the local reaction was observed.

Adult↗
PubMed1984

Risks and benefits of vaccinations.

Any medical intervention is expected to prevent sickness and complications of a disease rather than to induce them. This is true for therapy as well as prophylaxis. Special formulas have been developed to calculate the risks and benefits of vaccinations simply but with sufficient accuracy. The risk ratio (Q) tells how many times the risk of contracting certain complications or even death from a disease is greater in unvaccinated than in vaccinated individuals. The risk difference (D) directly expresses the number of complications or deaths that may be prevented by a certain vaccination. It is even possible to evaluate the epidemiologic trend of a disease and to calculate or estimate the point of time when the risks of disease and vaccination are just balanced, ie, when a vaccination has lost its beneficial effect. Vaccinations against measles, poliomyelitis and tick borne encephalitis in Austria are highly beneficial. BCG vaccination is still beneficial on a low level in Austria as far as protection against tuberculosis is concerned. This effect will persist for the rest of this century. The benefit of pertussis vaccination depends on the local epidemiologic situation. It has expired for non-risk groups in Austria since 1976 but continues to persist in the US.

Austria↗
PubMed1984

[A new ELISA micromethod for the determination of tetanus antibodies].

Due to its simplicity, accuracy and economy, the ELISA technique is a suitable method also for the determination of tetanus antibodies. By the method described, a titration curve is established from each serum to be investigated as well as from a standard serum. The horizontal distance between standard and unknown serum expressed in log2 titre steps is called titre difference. From this titre difference and the concentration of the standard serum the concentration of the unknown serum can be calculated. By means of an appropriate computer this evaluation can be done automatically. The variation coefficient with regard to concentration was 18.3%. A comparison with the toxin neutralisation test showed a correlation coefficient of 0.87. The application of this method to various problems is described.

Antibodies, Bacterial↗
PubMed1983

Immunogenicity and side-effects of a new tetravalent meningococcal polysaccharide vaccine.

A new tetravalent meningococcal polysaccharide vaccine containing groups A, C, W 135, and Y was administered to 40 healthy adults. The vaccine was well tolerated and bactericidal assay showed mean titre increases for the meningococcal polysaccharide groups A, C, W 135, and Y of 5.0, 7.8, 8.2, and 5.9 log(2) titre steps, respectively. The immunogenicity and side-effects of the vaccine were similar to those associated with monovalent and bivalent vaccines containing group A and C meningococcal polysaccharides.

Adult↗
PubMed1982

Immunoglobulin allotypes and immune response to meningococcal polysaccharides A and C.

Serum samples were collected from 113 healthy Caucasian volunteers before and after vaccination with meningococcal polysaccharides (MPS) group A and group C. Antibodies to MPS group A and group C were measured and sera were typed for several Gm and Km(1) allotypes. A significant association was found between the Gm 1,3,17; 5,13,14,21 phenotype and low immune responsiveness to MPS group A. These results suggest the possible existence of an immunoglobulin allotype-linked immune suppression (Is) gene(s) in man.

Adult↗