The sensitivity of detection of influenza H1N1 and H3N2 virus was 0.10 TCID_ 50 /50 μl by the second PCR and that was 0.01 TCID_ 50 /50 μl for influenza B virus.
28 of the influenza B viruses belonged to the B/Victoria lineage and were similar antigenically to the vaccine strain B/HongKong. 1 influenza B virus belonged to the B/Yamagata.
The sensitivity of detection of influenza H1N1 and H3N2 virus was 0.10 TCID_ 50 /50 μl by the second PCR and that was 0.01 TCID_ 50 /50 μl for influenza B virus.
28 of the influenza B viruses belonged to the B/Victoria lineage and were similar antigenically to the vaccine strain B/HongKong. 1 influenza B virus belonged to the B/Yamagata.
The specificity of the technique was verified in detecting another 7 respiratory viruses including influenza B virus, human parainfluenza virus 2, coxsackievirus serotype B_3 and B_5 and human adenovirus serotype 2、3 and 7, none of these viruses were found positive in the same multiplex PCR conditions.
Results also showed that the evolution of influenza B virus was under both strong positive selection and negative selection,which was contrary to previous reports.
Methods Primers were designed from highly conserved region of the hemagglutinin (HA) gene of influenza H1N1,H3N2 and B virus and MRT-PCR was performed.
Methods Influenza A (H3N2, H1N1) and B virus were inoculated in MDCK cells, MEK cells and FRhK-4 cells under different culture conditions to observe cytopathic effect (CPE), hemagglutination titer.
Results The result showed that positive seroconversion rates of anti - H1N1, anti - H3N2 and anti- HI were raised respectively from 1.56%,53. 13% and 53.60% to 82. 81% , 87. 50% and 97.92%,and antibody density increased respectively 18. 9,2.9 and 5.79 times of seroconversion density before vaccination.
Both vaccines caused a more than three-fold rise in geometric mean titers against influenza A strains, and about a twofold rise in geometric mean titers against influenza B/Hong Kong/5/73.
In contrast, about 70% of the patients on hemodialysis had responded to influenza A H1N1 and H3N2 vaccines while only 50% of the patients on hemodialysis had responded to influenza B antigen.
Optimization of baculovirus transduction on freestyleTM293 cells for the generation of influenza B/Lee/40
Nebularine (9-β-ribofurnosyl purine) is a naturally occurring purine nucleoside which is structurally similar to adenosine and it inhibits the growth of tumor cells and influenza B virus.
Amantadine blocks channel activity of the transmembrane segment of the NB protein from influenza B
Nebularine (9-β-ribofurnosyl purine) is a naturally occurring purine nucleoside which is structurally similar to adenosine and it inhibits the growth of tumor cells and influenza B virus.
Secondary infection (in the absence of neutralizing antibody) greatly enhances both the rapidity and the magnitude of this γδ T cell response for mice that are primed with a different type A influenza virus, but not with an influenza B virus.
Infectivity of influenza B virus in cultured human muscle
Severe muscle symtoms, particularly in children, are frequently associated with influenza B virus infection.
In this study we examined the effects of influenza B virus (Lee Strain) on cultured human muscle by light and electron microscopy (EM), immunofluorescence, hemadsorption and plaque assays.
The present paper describes the detection of antibody to influenza B virus in pig populations in Guizhou,China. Results suggested that pigs could be the natural host for all types of influenza virus and in a few pigs might be infected two different types or subtypes of influenza virus. The infection rate in pigs was different among different types or subtypes. The infection rate of H3N2 was about 14% and those of type B and C about 1 %, No antibody was detected against strains having disappeared in human populations....
The present paper describes the detection of antibody to influenza B virus in pig populations in Guizhou,China. Results suggested that pigs could be the natural host for all types of influenza virus and in a few pigs might be infected two different types or subtypes of influenza virus. The infection rate in pigs was different among different types or subtypes. The infection rate of H3N2 was about 14% and those of type B and C about 1 %, No antibody was detected against strains having disappeared in human populations. Meanwhile, only H3N2 viruses were isolated from 2.5% of pig lung and trachea, all isolates having been obtained in winter and spring seasons. Antibody tests with different Strains of infuenza B virus pointed out that like type A and C influenza viruses, in fluenza B virus in pigs might possibly be transmitted trom human due to closer human contact.
A comparison of RNA migration rates in polyacrylamid gel ( PAGE ) of influenza B virus strains prevalent in various periods was carried out. The result obtained indicated that their electropherotypes were different.This difference of RNA migration in PAGE corresponded with serological analysis of these strains of influenza B virus.
444 sera were tested for the HI antibodies to influenza A(H_1N_1), A (H_3N_2)and B viruses by hemagglutination inhibition (HI) test in the suburbs of Jinan in May 1983. The results were as follows: 1.The positive rates of HI antibody against the new H_1N_1 virus (strain A/Tietsin/78/77) is the highest in age groups 10-14 and 15-19, being 76.3%-85.2% and so the geometric mean titre(GMT), being 1: 13.71-1: 14.72. The age groups 5-9 and 20-21 being the next. 2. Antibody prevalence rate against H_3N_2 viruses(strain...
444 sera were tested for the HI antibodies to influenza A(H_1N_1), A (H_3N_2)and B viruses by hemagglutination inhibition (HI) test in the suburbs of Jinan in May 1983. The results were as follows: 1.The positive rates of HI antibody against the new H_1N_1 virus (strain A/Tietsin/78/77) is the highest in age groups 10-14 and 15-19, being 76.3%-85.2% and so the geometric mean titre(GMT), being 1: 13.71-1: 14.72. The age groups 5-9 and 20-21 being the next. 2. Antibody prevalence rate against H_3N_2 viruses(strain A/Shanghai/31/80) and the GMT is the highest in age groups less than 15 years, being 82.6%-100% and 1:28.61-1:65.20 respectively, and the second are aged 15-19 years and 55-64 years. 3. Antibody determination on influenza B (strain B/Shanghai/32/80) showed that people who fall into 20-24 and 45-54 age groups tend to lack antibodies and the positive rates are lower than other age groups and so does the GMT.