Biomedical subjects
Publications and source records attributed to L Brydak.
Vaccination was performed by influenza virus vaccine trivalent type A and B. We vaccinated about 75,000 persons in Poland in different groups of age. HI and NI tests were used for testing antibody level for A/Taiwan/1/86 (H1N1), A/Beijing/353/89 (H3N2) and B/Panama/45/90. The rise of antibody level was statistically significant.
Vaccination was performed by influenza virus vaccine, trivalent type A and B. We vaccinated about 50,000 persons in Poland in different groups of age. HI and NI tests were used for testing antibody level for A/Taiwan/1/86 (H1N1), A/Shanghai/16/89 (H3N2) and B/Yamagata/16/89. The rise of antibody level was statistically significant.
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The level of antibodies was tested in 9 age groups since 6 years up to over 75 years of age for H and N of influenza A(H1N1), A(H3N2) and B in epidemic season 1990/91. The highest GMT were found in all age groups for H3-A/Shanghai/16/88, much lower for H1-A/Taiwan/1/86. The titers were almost the same in all age groups excluding 6-8 years where GMT was much higher. The lowest titers were found for hemagglutinin of B/Yamagata/16/88 and different in different age groups. The highest GMT of neuraminidase were found for N2 in group 41-50 years old, in other groups were different. GMT for N1 were differentiated, but in 51-64 years old group was 3.5 times higher in comparing to the lowest value. For B neuraminidase the titer of antibodies was the highest in 31-40 years old group, and the lowest for 41-50 old people.
Five strains of influenza viruses A(H3N2) replicated at low temperature passaged in cotton rats were reisolated. The properties of these strains replicated at low temperature were compared before and after passage in susceptible animals to check the stability of some its markers. At the same time original viruses replicated at 37 degrees C--which are different in epidemiological potency--were compared. The following parameters being tested: NA activity, HA titers, heat inactivation NA and Ha, Michaelis constants and optimum pH. We observed some differences between strains both replicated at low temperature after passage in the susceptible animal organism and original viruses from 37 degrees C. Viruses replicated at low temperature from original epidemiostrain are really cold adapted and remained stable after passage in the animals when the others derived from no epidemic strain are not stable.
Resistance against proteolysis enzymes, detergents and chemical group-specific reagents has been compared for the neuraminidase and hemagglutinin of influenza virus replicated at low temperature and original strain replicated at 37 degrees C before and after passage in the susceptible animal organism - cotton rat. Our study indicated great differences between strains and temperature conditions to resistance of the neuraminidase and hemaglutinin to proteolytic enzymes, detergens and chemical group specific reagents. No differences was found for sensitivity of influenza virus replicated at low temperature before and after passages for 3 strains -A/Pol/L/71, A/Phil/2/82, A/Pol/79/85 which are really cold adapted viruses. On the other hand neuraminidase of this strains was more resistance to these treatments.
Swiss white mice were given intranasally suspension of influenza A virus (H3N2) isolated at different period of time and replicated in lowered temperatures in 11 days old chicken embryos. The presence of antigen in lung of animals was detected by IF. They were given the virus replicated at 30 degrees C at different rate depending on strain tested. No distinct differences were observed in haemagglutination inhibition antibody level. On the other hand the level of neuraminidase activity inhibiting antibodies level was significantly higher after giving virus replicated at 30 degrees C than after giving the virus replicated at 37 degrees C. In the case of epidemic strains 4-5 fold fold increase of immunogenicity of neuraminidase component was observed and in the remaining strains immunogenicity of neuraminidase increased 1-5-fold only.
Influenza A/H3N2/ virus strains derived from various isolations and replicated in lowered temperatures (37 degrees, 35 degrees, 33 degrees, 30 degrees) in chicken embryos were used for the study. An alteration of temperature optimum of neuraminidase activity was established after 12-15 passages of influenza virus in lowered replication temperature and it differed depending on tested strain. During adaptation process of viruses to lowered replication temperatures no correlation between neuraminidase activity and haemagglutinating titer was seen.
A total of 1215 persons, divided into 4 groups, were immunized with influenza vaccines A (highly purified, whole-virion), B (subunit, containing H and M), and C (conventional, commercial partly purified by Sharplers centrifugation). Post-vaccination reactions were followed, and serological tests (HI and NI) were performed with serum specimens taken from each vaccine 4 times during and after the vaccination period. The results point to clear superiority of purified and subunit vaccines over the conventional one.
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Peptide maps were prepared by high-voltage electrophoresis and chromatography for t 30 degrees C mutant and the original strain A Port Chalmers 1/73 H3N2 of influenza virus. Clear differences in the distribution and number of spots between the mutant and the original strain were found. The differences are due presumably to changes in the amino-acid sequences.
The t 30 degrees C mutant of A Port Chalmers 1/73 (H3N2) influenza virus passaged in cotton rats was reisolated. The original mutant and the reisolated virus were compared, the following parameters being tested: NA activity, HA titer, sensitivity of NA and HA to proteolytic enzymes, detergents and temperature, and Michaelis constant of NA. No differences were found in the parameters tested, thus suggesting that features of the mutant remained stable after passage in the susceptible animal organism.
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Cold adapted variants of influenza virus, replicated at 37, 35, 33 and 30 degrees C, were tested for capability to multiply in ferrets and to induce H and N antibodies. Virus grown at 30 degrees C differed from the other in electrophoretic mobility of its polypeptides in PAGE, in inducing higher level of N antibodies, and in higher intensity of immunofluorescence reaction in the respiratory tract.
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