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Biomedical subjects

S Iwarson

Publications and source records attributed to S Iwarson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Antibodies against Haemophilus influenzae type b and tetanus in infants after subcutaneous vaccination with PRP-T/diphtheria, or PRP-OMP/diphtheria-tetanus vaccines.

In an open randomized study, serum antibodies against Haemophilus influenzae type b capsular polysaccharide (PRP) and tetanus toxoid were determined in 146 Swedish infants; 75 of them received PRP conjugated to tetanus toxoid (PRP-T) concurrently with diphtheria toxoid vaccine, and 71 received PRP conjugated to an outer membrane complex of Neisseria meningitidis (PRP-OMP) concurrently with diphtheria-tetanus toxoid vaccine. Injections were given subcutaneously at ages 3, 5 and 12 months. One month after the second injection, the PRP-T recipients had a geometric mean (GM) concentration of 0.38 microgram/ml and only 69% had PRP antibodies > or = 0.15 microgram/ml (considered a protective level). In the PRP-OMP group the GM concentration was 0.44 microgram/ml and 85% had PRP antibodies > or = 0.15 microgram/ml. One month after the third injection, 99% of the infants in both groups had PRP antibodies > or = 0.15 microgram/ml, but PRP-T recipients had significantly higher GM concentration than infants vaccinated with PRP-OMP, 10.21 micrograms/ml vs. 1.90 micrograms/ml (P < 0.001). After all three injections the diphtheria-tetanus toxoid vaccine elicited higher GM concentrations of tetanus toxoid antibodies than did the PRP-T vaccine, but both vaccines induced antibodies above the proposed protective level, 0.01 IU/ml. The reason for the lower than expected immunogenicity of the two Haemophilus influenzae type b conjugate vaccines has yet not been established. For PRP-OMP the most probable explanation is the use of a lot of low immunogenicity, but the route of administration also has to be considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Bacterial↗
PubMed1994

The natural course of chronic hepatitis C.

In 1988, investigators from the Chiron Company (USA) detected the non-A, non-B agent and named it hepatitis C virus (HCV). An anti-HCV antibody assay (ELISA) and subsequently confirmation tests (immunoblot and polymerase chain reaction) were developed. HCV exposure results in a chronic infection in a majority of cases. This chronic infection is associated with slowly progressive chronic liver disease. Chronic HCV infection is, like HBV, also associated with the development of hepatocellular carcinoma. Most HCV carriers are infected by parenteral routes. Intravenous drug users have the highest risk of becoming infected. Intrafamiliar spread is seen in certain parts of the world but sexual and perinatal transmission does not play an important role in spreading the infection. Antiviral therapy (alpha-interferon) in patients with chronic hepatitis C will normalize liver function tests in about 25% of the cases.

Carrier State↗
PubMed1994

Substantial decline of notified hepatitis B in major parts of Europe after 1985.

A decline in the incidence of notified hepatitis B cases has been observed in major parts of Europe since the mid-1980s. Sweden may be taken as an example of a low prevalence area in the north where notifications of acute hepatitis B declined from 6 cases/100,000 inhabitants in 1985 to only 3/100,000 annually in 1988-91. Choosing W. Germany as an example from central Europe, the notification rate of acute hepatitis B declined from 11 cases/100,000 inhabitants in 1984 to 6-8/100,000 in 1988-91. In Italy, a dramatic decline in hepatitis B infections has occurred since 1985, according to the national hepatitis surveillance system (SEIEVA), from 12 cases/100,000 inhabitants in 1985 to 5/100,000 in 1988-91. A similar trend has also been observed in the USA which seems to be unrelated to vaccination, since only limited vaccination programs have been initiated in high-risk groups. Also in Europe, changed sexual and needle-usage practices in risk groups such as drug addicts and male homosexuals have probably contributed to the observed decline. In southern Europe, rapidly improving socio-economic conditions and improved medical precautions against hepatitis B have probably also been important factors.

Europe↗
PubMed1993

Strategies for immunization against hepatitis B in western Europe.

In western Europe there has been a striking decline in the incidence of hepatitis B virus infection during the second half of the 1980s. Only a minor part of this decrease is the effect of vaccination, since rather limited vaccination programmes have been introduced in most west European countries. The policies for recommendation of hepatitis B vaccination have differed from north to south in Europe due to different risks of exposure to hepatitis B virus. In Scandinavia, vaccination has mainly been recommended for health-care workers with frequent blood contact, while in Germany and in France vaccination has been recommended for all health-care workers with patient contact. Further south, as in Italy, all health-care workers have been considered a risk group, and vaccination is recommended for all newly recruited workers and students.

Europe↗
PubMed1993

World-wide strategies for immunization against invasive Haemophilus influenzae type b disease.

Data available on the immunogenicity, safety and efficacy of Haemophilus influenzae type b (Hib) conjugate vaccines are encouraging and the prospects for controlling invasive Hib disease are good. The incidence of Hib meningitis in many industrialized countries increases sharply between 6 and 12 months of age and the first two doses of a Hib vaccine should ideally be given before that. In non-industrialized countries, the incidence peak is seen very early in life, which would require a very early start for Hib vaccination in such areas.

Adolescent↗
PubMed1992

Diverging policies for vaccination against hepatitis B.

Policies toward vaccination against hepatitis B vary globally according to local prevalence and the population of infected individuals. In the present report, vaccination plans, policies, risks, and experiences of both apparent successes and failures are described. Possible plans, including local vaccine production, are discussed in regard to problems of third-world countries with high HB prevalence. Recommendations are made for vaccination policies in various circumstances.

Developing Countries↗
PubMed1992

The main five types of viral hepatitis: an alphabetical update.

The rapidly increasing knowledge in the field of viral hepatitis warrants regular updates. Clinical studies with new hepatitis A vaccines have shown that they are safe, well-tolerated, and effective. Several reports on hepatitis B virus (HBV) variants have appeared. Surface antigen mutants may have an important influence on vaccine prophylaxis because existing vaccines may not protect against infection with these variants. Hepatitis D virus is a circular RNA virus that requires the presence of HBV for successful infection. The requirements for the dual expression of these viruses are unknown and their relation is complex. Hepatitis C virus (HCV) is a RNA virus that has homology with the flaviviridae. This is a rather common agent in most populations studied and often causes chronic infection but little is known about its spread. Hepatitis E virus is a RNA virus which is usually spread by contaminated water in developing countries. The disease causes high mortality in pregnant women. The existence of further viral hepatitis agents have been suggested but hard data confirming this is so far lacking.

Animals↗
PubMed1991

Strategies for immunization against invasive Haemophilus influenzae type b infection.

Available data on the immunogenicity, safety and efficacy of Hib conjugate vaccines are encouraging and the prospects for having a means to control invasive Hib disease are good. Most of the third generation Hib vaccines seem to prevent invasive Hib disease at a level of efficacy that motivates worldwide mass immunization of infants. The peak incidence of Hib meningitis occurs before the age of 1 year in most industrialized countries and the most desirable time to start vaccination against Hib is at 2-3 months of age. In many countries a Hib conjugate vaccine may ideally be coordinated with the DTP immunization programme. In non-industrialized countries the peak incidence of Hib meningitis occurs earlier than in industrialized countries, which means that in these areas immunization against Hib meningitis should start earlier, for instance at 6 weeks when the first DTP vaccine injection is given in many countries.

Haemophilus Infections↗