POLYOMAVIRUS VACCINATION

By David Hannon, DVM

Well, Branson Ritchie finally did it. Not only did his research group successfully create an effective polyomavirus vaccine, but they also made it safe as well. That's the good news. The bad news is that right now the USDA licensing is all tied up in a ball of red tape, and we're looking at another 6-8 months before it becomes commercially available. However, in the face of an outbreak, Biomune, the company which is marketing the new vaccine, can make an autogenous vaccine from the virus isolated from a bird that has succumbed to the infection. And this vaccine can be utilized in the same manner as the commercial form will be, once it is on the market.

This new vaccine was field tested on 21 different bird species, including macaws, Amazons, cockatoos, and African greys. It was shown to stimulate polyomavirus antibodies (antibodies are proteins that the body makes in order combat infection) in 95% of the vaccinated birds. The only vaccination reactions noted were discoloration or thickening of the skin at the injection site, or, on rare occasion, granuloma formation (cockatoos appear to be more sensitive to these reactions). All reactions should resolve within six weeks.

The current recommendation is to vaccinate all birds 20 days old or older. Initially, each bird should get two doses 2-3 weeks apart, and annually thereafter. Birds should be vaccinated during quarantine, and at least one month prior to shipping, and all vaccinated birds should be considered susceptible to the disease until two weeks after the second injection. Adult birds tend to have a better immunological response than neonates. In order for the vaccine to be effective, it must be stored and administered properly, utilizing the proper dosage and route. Dr. Ritchie recommends vaccinating all non-clinical birds in the face of an outbreak in order to protect uninfected birds. Although the vaccine will not hurt an infected bird, it will not offer it any protection either, and the bird may still die.

Although the vaccine will help prevent polyomavirus outbreaks, proper husbandry must also be utilized. Dr. Ritchie has come up with a list of techniques for preventing and controlling polyomavirus outbreaks in the nonbudgerigar psittacine nursery. These are as follows:

Prevention:

1. Vaccinate susceptible adults and neonates.
2. Never ship or accept an unvaccinated bird.
3. Do not maintain budgerigars, cockatiels, or lovebirds in the same airspace with other unvaccinated psittacine neonates.
4. Clean and disinfect the nursery environment regularly.
5. Ship only weaned birds.
6. Use biosecure shipping containers to prevent virus exposure during transport.
7. Maintain a closed aviary, and strictly limit visitations by non-aviary personnel.
8. Never return a neonate to the nursery if it has been exposed to other birds.
9. If new birds must be added to the flock, vaccinate and quarantine them for a minimum of 60-90 days.
10. Never mix neonates from multiple sources in the same airspace.
11. Use separate feeding instruments for each bird.
12. Never use a feeding utensil and place it back into a common food container.

Control:

1. Isolate clinically infected birds.
2. Carefully vaccinate exposed birds making sure that virus transmission is not facilitated by the handling procedure.
3. Never place a clinically ill bird in the same airspace with birds in the nursery.
4. Isolate birds in direct contact with clinically ill birds or those that are shedding virus.
5. Completely clean and disinfect the nursery environment.
6. Use the DNA probe to test the nursery environment for viral contamination.