Asifa Rasool Bhatti
Factors Effecting Activity Of Haemagglutinin Of Avian Influenza (H9 Type)Virus - 2002
Avian influenza virus (AIV) was propagated in 09-day-old chicken embryonated eggs and after 72 hours post incubation the AAF and CAM were harvested and AIV was confirmed by spot agglutination test and agar gel precipitation test.
The AIV (H9 type) agglutinated red blood cells from chicken, dog, horse, parrot, pigeon, guinea pig, buffalo and human blood group O but it did not agglutinate the RBC's from sheep and rabbit. The
virus gave HA titer of 1:512 when RBC's from chicken, human blood group O÷ve and dog were used. Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water when used with chicken RBC's (0.5 and 1%) resulted in similar HA titer 1:512. However HA titer of the virus was low (1:256) when normal saline was used as a diluent.
AIV agglutinated 0.5% and 1% chicken RBC's in 35 and 25 minutes respectively and both concentrations of RBC's gave similar HA titer (1:512) in the presence of Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water. However AIV with normal saline and 0.5% and 1% chicken RBC's gave a lower HA titer of 1:256 in 35 and 25 minutes.
It was also found that RBC's concentration of 0.1% did not result in any agglutination by the virus, even after 60 minutes.
Storage of AIV at either 4°C or -20°C did not affect its hemaggitination activity in 6 months. However storage at 37°C resulted in loss of hemagglutination activity after 4 months. Storage at room temperature also resulted in loss of HA but at a lower pace as appended to 37°C temperature. However, vaccines prepared from the alliquotes stored at different temperature did not different in terms of antibody response (HI titer of GMT 137.2) indicating that the loss of hemagglutination activity did not corresponds with loss of immunogencity.
Department of Microbiology
0831,T
Factors Effecting Activity Of Haemagglutinin Of Avian Influenza (H9 Type)Virus - 2002
Avian influenza virus (AIV) was propagated in 09-day-old chicken embryonated eggs and after 72 hours post incubation the AAF and CAM were harvested and AIV was confirmed by spot agglutination test and agar gel precipitation test.
The AIV (H9 type) agglutinated red blood cells from chicken, dog, horse, parrot, pigeon, guinea pig, buffalo and human blood group O but it did not agglutinate the RBC's from sheep and rabbit. The
virus gave HA titer of 1:512 when RBC's from chicken, human blood group O÷ve and dog were used. Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water when used with chicken RBC's (0.5 and 1%) resulted in similar HA titer 1:512. However HA titer of the virus was low (1:256) when normal saline was used as a diluent.
AIV agglutinated 0.5% and 1% chicken RBC's in 35 and 25 minutes respectively and both concentrations of RBC's gave similar HA titer (1:512) in the presence of Phosphate buffer saline, haemagglutination, inhibition buffer and 0.5% peptone water. However AIV with normal saline and 0.5% and 1% chicken RBC's gave a lower HA titer of 1:256 in 35 and 25 minutes.
It was also found that RBC's concentration of 0.1% did not result in any agglutination by the virus, even after 60 minutes.
Storage of AIV at either 4°C or -20°C did not affect its hemaggitination activity in 6 months. However storage at 37°C resulted in loss of hemagglutination activity after 4 months. Storage at room temperature also resulted in loss of HA but at a lower pace as appended to 37°C temperature. However, vaccines prepared from the alliquotes stored at different temperature did not different in terms of antibody response (HI titer of GMT 137.2) indicating that the loss of hemagglutination activity did not corresponds with loss of immunogencity.
Department of Microbiology
0831,T