Studies in Equine Encephalomyelitis.

This research focused on the propagation of the Equine Encephalomyelitis virus through various avian embryos. The researchers concluded that the infected developing chick embryo, which produces a high amount of virus, is a valuable tool for creating a concentrated antigen capable of stimulating immunity in susceptible animals.

Propagation of Equine Encephalomyelitis Virus

• The virus of Equine Encephalomyelitis, a disease affecting horses, was cultivated in a developing chick embryo. This method has been known to increase virus concentration (titre).
• The purpose of increasing virus titre is to produce a large amount of virus, which can be used to create a concentrated antigen. The antigen, when deactivated, can stimulate an immunity response in susceptible animals.

Experimenting with Different Avian Embryos

• The researchers also explored propagating the virus in different kinds of avian embryos. This investigation was considered important to discover if there are variations among different types of avian embryos.
• In addition to chicks, ducks and robins were also used in the experiment. It was noted that the time each species took to reach a similar stage of development varied. Duck embryos required fifteen days to reach a comparable stage with ten-day chick embryos, whereas robin embryos reached the same stage in six days.

Method of Inoculation

• Virus inoculation was conducted using the modified Burnet technique, as described in an earlier paper. The eggs were incubated at 37 Degrees Celsius with sufficient moisture.
• The eggs were frequently checked, and upon the death of the embryo, it was aseptically removed and macerated in a sterile glass bottle with glass beads and placed in a buffer solution.
• The virus propagation, or the increase in the virus titre, was observed and noted five days later.

Strain of the Virus

• The researchers used a strain of the Equine Encephalomyelitis virus, western type, isolated in 19372 for this experiment. They found that the titre of the virus increased with each passage through the chick embryo, reaching a peak on the twenty-third passage.