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Biomedical subjects

S Krugman

Publications and source records attributed to S Krugman.

At least 73 records · Page 4Linked to original sources

Persistence of maternal antibody in infants beyond 12 months: mechanism of measles vaccine failure.

A serologic study was made in 34 children immunized against measles at the age of 12 months. Using a sensitive virus neutralization test, it was found that many of the children had pre-existing maternal antibody to measles virus. Children with high pre-existing antibody titers failed to seroconvert. Children with lower pre-existing antibody titers seroconverted, but the resulting antibody titer was significantly lower than in children without pre-existing antibody titer. The results of this study demonstrate a probably mechanism for measles vaccine failure in 12-month-old children and support the recommendation of the Public Health Service Advisory Committee on Immunization Practices to postpone measles vaccination to 15 months of age.

Age Factors↗

Effect of human immune serum globulin on infectivity of hepatitis A virus.

A standard preparation of immune serum globulin containing a titer of immune adherence hemagglutination hepatitis A antibody of 1:3,200 neutralized the infectivity of MS-1 serum. An inoculation of MS-1 serum was followed by the following evidence of hepatitis A infection in eight of 14 seronegative recipients: (1) abnormal values for serum aspartate aminotransferase after an incubation period of 29-42 days, and (2) no detectable immune adherence hemagglutination hepatitis A antibody (less than 1:5) before exposure, and an eightfold or greater increase in antibody titer during convalescence. In contrast, inoculation of the mixture of MS-1 serum and immune serum globulin was followed by (1) normal values for aspartate aminotransferase in all eight seronegative recipients, and (2) evidence of an antibody response (indicating subclinical infection) in two of the eight. Under the conditions of this study, the use of the preparation of immune serum globulin described prevented or modified hepatitis A infection.

Antibodies, Viral↗

Comparison of serological tests for antibody to hepatitis A antigen, using coded specimens from individuals infected with the MS-1 strain of hepatitis A virus.

To compare serological tests for antibody to hepatitis A antigen (anti-HA), we tested 15 paired serum specimens, submitted under code, from individuals infected with the MS-1 strain of hepatitis A virus. Immune electron microscopy (IEM), immune adherence hemagglutination (IAHA), and solid-phase radioimmunoassay (RIA) tests for anti-HA were performed with hepatitis A antigen (HA Ag) derived from human stool; results were also compared with previously reported titers determined by IAHA with HA Ag derived from marmoset liver. Antibody titers (IAHA and RIA) and ratings (IEM) determined with stool-derived HA Ag compared favorably, and a seroresponse to HA Ag was detected by all three methods for every serum pair tested. Differences in titers were noted between IAHA tests with liver-derived and with stool-derived HA Ag, but the discrepancies could be accounted for by differences in test technique. The agreement found in this study among the three techniques was quite good and confirms the specificity and sensitivity of tests for anti-HA that are done with stool-derived HA-Ag.

Antibodies, Viral↗

The prevention of viral hepatitis.

Studies with heat-inactivated MS-2 serum have indicated that active immunization against hepatitis B infection can be achieved even though the virus has not been cultivated in tissue culture. The development of new biophysical, biochemical and immunological techniques has increased knowledge of the hepatitis B virus and its associated antigens. In the wake of these recent developments the accumulating evidence indicates that active immunization could be achieved by the use of purified hepatitis B surface antigen or by one of its polypeptides or glycolipids.

Hepatitis B virus↗

Viral hepatitis, type A. Identification by specific complement fixation and immune adherence tests.

Hepatitis A antibody was detected by specific immune adherence and complement-fixation tests in a study involving 473 serum specimens from 20 patients who had viral hepatitis, Type A. In all 20 patients who had no detectable immune adherence antibody (less than 1:5) before onset of hepatitis high levels (greater than or equal to 1:1024) developed one to four weeks later, occasionally reaching peak levels exceeding greater than or equal to 1:81,920 several months thereafter. Five to 10 years later the immune adherence antibody levels ranged between 1:640 and 1:20,480. In general, the complement-fixation test was not as sensitive or as specific as the immune adherence test. These findings indicate that the immune adherence test should be a valuable tool for diagnosis, for epidemiologic surveys, for identification of susceptible and immune persons, for quantitative assays of gamma globulin and for identification of hepatitis A virus in attempts to propagate the virus in cell culture.

Animals↗

Viral hepatitis: recent developments and prospects for prevention.

During the past decade new development in hepatitis research have shed new light on the etiologic, epidemiologic, immunologic, and prophylactic aspects of type A and B hepatitis virus infection. Recent advances in hepatitis A virus research include: (1) identification of the virus as a 27 nm particle with characteristics resembling an enterovirus, (2) transmission of the infection to marmosets and chimpanzees, and (3) development of specific complement fixation and immune adherence antibody tests. Recent advances in hepatitis B research include: (1) identification of the virus as a 42 nm particle (Dane particle) containing an outer coat, the hepatitis B surface antigen, and an inner core, the hepatitis B core antigen, (2) development of specific tests to detect the hepatitis B antigens and their respective antibodies, (3) transmission of the infection to chimpanzees, (4) development of a specific hepatitis B immune serum globulin, and (5) development of an inactivated hepatitis B vaccine.

Animals↗

Viral hepatitis type B: propects for active immunization.

Studies conducted in 1970 and 1971 with heat-inactivated MS-2 serum revealed that this active immunizing procedure was associated with a protective effect, a more attenuated hepatitis B infection and a decreased hepatitis B carrier rate. More recent studies have revealed striking differences in the response of unimmunized and immunized persons following a parenteral exposure to the MS-2 strain of hepatitis B virus. Serial tests for the detection of hepatitis B surface antigen (HBsAg), DNA polymerase activity, serum transaminase (SGOT), antibody to HBsAg (anti-HBs) and antibody to hepatitis B core antigen (anti-HBc) revealed the following findings. In serosusceptible unimmunized persons HBsAg was detectable about 4 weeks after exposure, DNA polymerase activity at about 6 weeks, abnormal SGOT levels at about 8 weeks, anti-HBc at about 8-10 weeks, and anti-HBs usually after 20 weeks. In successfully immunized persons HBsAg, DNA polymerase activity, abnormal SGOT levels, and anti-HBc were not detectable, evidence of a booster response of pre-existing or non-detectable anti-HBs was observed one to two weeks after exposure. Studies by various investigators have revealed that anti-HBs is associated with protection and resistance to reinfection. In contrast, anti-HBc is not protective and does not correlate positively with either resistance to infection or recovery from infection. The availability of sophisticated biophysical and biochemical techniques has enabled several investigators to prepare candidate inactivated hepatitis B vaccines from purified preparations of HBsAg. The successful propagation of hapatitis B virus infection to susceptible chimpanzees has provided an excellent animal model for the evaluation of hepatitis B vaccines. At the present time various investigators are studying the immunogenic and protective effect of the vaccine in these animals. Prospects for the development of a vaccine for the prevention of viral hepatitis type B are encouraging. It is extraordinary that this objective will be achieved in spite of the failure to isolate the etiologic agent in tissue culture.

Animals↗

Seroepidemiologic survey of varicella: Value of specific fluorescent antibody test.

The sensitive varicella-zoster fluorescent antibody to membrane antigen (V-Z FAMA) test was used in a seroepidemiologic survey of two outbreaks of varicella involving 30 children. The attack rate of varicella based on clinical observations alone was 60%. The attack rate based on clinical and serological observations lay between 78% and 82%, after excluding those children who had detectable antibody at the time of exposure. No subclinical varicella infection was observed in this small series of patients. No boost in antibody response was observed in immunes who were exposed to varicella. No patients with detectable V-Z antibody by FAMA at the time of exposure developed clinical varicella. The V-Z FAMA test provided helpful information about the immune status of persons exposed to varicella.

Antibodies, Viral↗