Kinetics of humoral antibody response to trivalent inactivated split influenza vaccine in subjects previously vaccinated or vaccinated for the first time.

We studied differences in immune responses after first time immunization with a trivalent inactivated split influenza vaccine, or after vaccination in the preceding year, in 42 healthy volunteers (40 +/- 13 years). Sequential serum samples were collected over 40 weeks. Previously vaccinated volunteers exhibited 40-92% protective antibody levels in their prevaccination sera. Subjects vaccinated for the first time had higher response rates and meanfold antibody increases than those vaccinated previously. Both groups had protective antibody titres 59% 7 days after vaccination and 70% of vaccinees maintained protective antibody titres after 280 days. The results corroborate earlier findings on the rapid immune response and may have a bearing on future vaccination policy.

Influenza vaccination in older patients. Immunogenicity, epidemiology and available agents.

Excess hospitalisation and deaths attributable to influenza virus infections often occur during epidemics and even in interepidemic periods. Influenza vaccines in current use are inactivated preparations that contain 15 micrograms each of the most recently circulating influenza A (H3N2 and H1N1) and B viruses. At present, 3 types of inactivated influenza virus vaccines are available: (a) whole virus vaccines; (b) split virus vaccines; and (c) subunit vaccines. All 3 types are similarly immunogenic in primed patients. Vaccine efficacy depends on a close antigenic match between the vaccine composition and the influenza strains circulating in the human population. The continuous antigenic drift of the viral membrane antigens (haemagglutinin and neuraminidase) necessitates an update of the vaccine composition each year according to the recommendations of the World Health Organization (WHO). Subunit and split virus vaccines cause fewer systemic reactions than whole virus vaccines. At present, live attenuated influenza virus vaccines are not licensed. In perspective, combined administration of live and inactivated vaccines seems to be advantageous. Influenza vaccine is approximately 75% effective in reducing deaths in elderly and high risk persons. Several studies have shown that the antiviral agent amantadine is a useful adjunct to vaccination for preventing influenza A in institutional settings. Currently, the proper use of inactivated vaccine according to the recommendations of public health authorities is the only way to reduce the annual influenza-associated medical and economic burden.

Comparison of humoral immune responses to trivalent influenza split vaccine in young, middle-aged and elderly people.

A total of 296 volunteers in five different groups were immunized with one dose of the commercial 1991-1992 trivalent split influenza vaccine formulation A/Singapore/6/86 (H1N1), A/Beijing/353/89 (H3N2) and B/Yamagata/16/88. The groups differed in age (young adults, middle-aged and elderly) and history of previous vaccination. Antibodies were determined in pre- and postvaccination sera by haemagglutination inhibition assay and the results were evaluated as geometric mean titre, mean fold antibody increase, protection and response rates. No significant age-related differences among the protection rates were found. The proportion of vaccinees with antibodies > or = 40 ranged between 70 and 95%. Compared with the H3N2 and B components the antibody response to the H1N1-component was low. Residents of a nursing home fully vaccinated the previous year developed 7.6-8.4-fold antibody increases and showed 96-100% protection rates.

Rapid, easy and economical dot EIA for detection of antibodies to HIV-1 using recombinant env- and gag-proteins.

A rapid and simple screening test for antibodies to HIV-1 was designed on the principle of dot-EIA. Recombinant HIV-1 env and gag polypeptides are fixed on nitrocellulose sheets. Peroxidase conjugated protein A is used for detection of bound antibodies. After addition of hydrogen peroxide and 2-bromo-1-naphtol antigen-antibody complexes are visualized as discrete blue coloured spots. The test is completed within 15 min. Out of 111 sera positive by commercial EIA and Western blot analysis 110 were recognized by dot-EIA (sensitivity: 99.1%). False positive results compared with commercial EIA were found in 2 of 423 healthy blood donors (specificity: 99.5%).

[The expanded WHO vaccination program and the vaccination strategy in East Germany]. / Das erweiterte Impfprogramm der WHO und die Impfstrategie der DDR.

Evaluating the current stage and future trends of WHO's Expanded Programme on Immunization (EPI), conclusions for national immunization strategies have been considered. The global eradication of poliomyelitis is an important target. In 1988, an Immunization Advisory Group of the Ministry of Health has been founded. Recommendations regarding the update of immunization schedule have been elaborated. Changes are foreseen for BCG (deletion of revaccination), rubella (implementation of immunization for all girls aged 11/12 years), diphtheria (diphtheria/tetanus booster for adults), and measles (2-shot-strategy for young children and schoolchildren.

The intestine of ferret--a possible site of influenza virus replication.

Anal virus shedding and stimulation of the immune response were observed in ferrets after oral and rectal administration of influenza A/Hongkong/1/68 (H3N2) virus. Despite of the low pH in the stomach, the virus had reached the intestines after oral administration and was found in high concentration in faeces and in mucosal cells lining the colon. Using immunofluorescent staining, the virus antigen was detected in cytoplasm of columnar epithelial cells. Virus replication also occurred in the respiratory tract, probably as result of inhalation of anally shedded virus. However, the virus replication in the lungs did not seem essential for virus isolation from the intestines. Taking into account the very short food passage time in ferrets the results could indicate the replication of influenza A/Hongkong/1/68 virus in the digestive tract of ferrets.

[Inhibition of the hemolytic activity of influenza viruses by antibody]. / Hemmung der hämolytischen Aktivitäten von Influenzaviren durch Antikörper.

Haemolysis caused by influenza viruses is known to occur below pH 6; the pH-optimum for each virus strain is different. Clear dose-effect correlations were found to prevail between the amount of haemolysis and virus concentration. Antibody-mediated inhibition of haemolysis has been investigated with the strain A/PR/8/34 (H1N1) and the recombinant X-73 (H3N2). Inhibition of haemolysis by antisera against different influenza. A virus subtypes suggests that haemolysis inhibiting antibodies are not identical with haemagglutination inhibiting antibodies. The action of antibodies directed against host-cell specific components was excluded by adsorption procedures. Haemolysis inhibiting antibodies are thought to be directed against antigenic determinants of the haemagglutinin functioning as fusion factor.

[Effect of low pH values on the infectivity and neuraminidase activity of human and animal strains of influenza virus type A]. / Uber den Einfluss niedriger pH-Werte auf die Infektiosität und Neuraminidaseaktivität menschlicher und tierischer Stämme des Influenzavirus Typ A.

The influence of acidic pH on the infectivity and neuraminidase activity of human, equine and avian type A influenza virus strains has been studied. Following exposure to pH 3 human and equine strains lost their infectivity completely, whereas all investigated strains of the subtypes Hav6N2 and Hav7Neq2 retained a certain amount of infectivity. In contrast to human and equine strains the avian strains retained also 38% of their original neuraminidase activity after acidic treatment. Partial retention of infectivity and the relative stability of the neuraminidase following exposure to acidic pH are supposed to be linked together in avian influenza virus strains implicating neuraminidases for their ability to prevent the aggregation of virions.

[Demonstration of the oncogenic activity of cell cultures using antithymocytic serum]. / Nachweis der Tumorbildenden Aktivität von Zellkulturen durch Anwendung von Antithymozytenserum.

The authors examined 10 cell strains of different origin as to their effect on mice by means of antithymocytic (ATC) serum. In dependence on the strain used the tumors developed in different number and with different growth tendency. In control animals not treated by the ATC serum, small ganglions developed in some cases which, however, disappeared in 2--3 days. Both strains of diploide cells WI 38 and LEP and primary cultures of chicken fibroblast from embryos of SPF chickens did not develop any tumors. The antithymocytic serums from calfs were found to be less toxic for mice than the rabbit sera.

[Biological properties of the mumps virus--behavior in the rct marker]. / Biologisches Eigenschaften des Mumpsvirus--Das Verhalten im rct-Marker.

12 different mumps virus strains or their variations were studied in the rct-marker in dog kidney cell cultures at 32 degree and 39 degree C. The results obtained were compared with those of the T50 marker ascertained earlier revealing considerably coincident data. Changes in culture conditions became clearly evident in both markers. Relations between their behaviour in vitro in vivo are discussed.

Evidence of tumorigenic activity of candidate cell substrates in vaccine production by use of antilymphocyte serum.

Candidate cell substrates for vaccine production must be controlled for the absence of tumorigenic activities. This test is done in most laboratories by heterotransplantation of living cells in Syrian hamsters either subcutaneously into newborns or into the cheek-pouch tissue of older ones. The necessity of a long observation period and high rate of intercurrent mortality among newborn hamsters are the disadvantages of this method. The method described by the authors is based on the use of three-week-old mice. Suspensions of living cells (at least 10(6)) were inoculated simultaneously with an antilymphocyte serum of bovine origin. The application of the antilymphocyte serum is repeated twice. Different heteroploid cell strains were studied and their tumorigenic activities were demonstrated. In no case tumors developed after inoculation of diploid cell strains. The results showed that the use of immunodepressed mice is an efficient method for the determination of the cell culture tumorigenic activity.

[Biological properties of the mumps virus. Behavior using the T50 marker]. / Biologische Eigenschaften des Mumpsvirus. Das Verhalte im T50-Marker.

The authors studied the behaviour of 11 mumps virus strains or variants including the thermolabile standard Jeryl Lynn strain under thermal charge (50 degrees C/30 min). Varants were obtained from the Soviet vaccinal strains Leningrad-3 by cultivation under various conditions. Incubation temperature and cellular substrate played an important role therein. Variants with various behaviour in the marker T50 resulted. It was found that passages at 32 degrees C at limited dilutions as well as those on chick embryos or in cultures of chicken fibroblasts increased their thermolability. Possible correlations between their behaviour in the marker T50 and the degree of di attenuation are discussed. (Ta)

[The influence of straw, particularly rice straw, together with calcium-cyanamide on the microbiological activity of two Portuguese soils (author's transl)]. / Der Einfluss von Stroh, insbesondere Reisstroh, in Verbindung mit Kalkstickstoff auf die mikrobiologische Aktivität zweier portugiesischer Böden

The influence of calcium-cyanamide upon the microbiological activity was tested in pot experiments under controlled conditions in two Portuguese soils (sandy and loamy) after the addition of rice or wheat straw (rice straw 0.275% N, wheat straw 0.307% N). The amount of straw was equalled to 100 dz/ha, the application of calcium-cyanamide to 25, 50 and 100 kg N/ha. In the containers treated with straw the total amount of microorganisms (Koch-method) was higher in sandy than in loamy soil after 30 days, but after 70 days it was higher in loamy soil. The content of active nitrogen (NH4 + NO3) increased, when calcium-cyanamide was added, but decreased after the application of straw. After 70 days sandy soil again showed an increase of active nitrogen. Straw increased the rates of CO2-production considerably, wheat straw was superior to rice straw. Calcium-cyanamide increased the CO2-production more in sandy than in loamy soil or German loess, which was also used for this experiment. Only in the case of rice straw higher doses of calcium-cyanamide had a positive effect. After 70 days the CO2-production rose only when rice straw was applied. The dehydrogenase-activity was increased in both soils, but a superiority of wheat straw occurred in sandy soil only. The microbiological activity in the pots with straw was higher in sandy than in loamy soil, the addition of calcium-cyanamide accelerated it. Doses of 25-50 kg N/ha are sufficient generally. The period of the formation of insoluble organic N-compounds, usually connected with the application of organic matter with a wide N:C-ratio, seems to be reduced by the addition of calcium-cyanamide.