Vaccines

Interest is growing in controlling coccidiosis by vaccination because immunological control is recognized as the only practical alternative to anticoccidial drugs in largescale production. (Chapman, 2002)

Large poultry companies usually vaccinate chicks at company-owned hatcheries. Smaller producers buy chicks from independent hatcheries, but some hatcheries do not offer coccidiosis vaccination. Small producers may need to do the vaccination themselves, once the chicks arrive at the farm.

Types of Vaccines

• Coccivac®: This vaccine was developed in the early 1950s. The “B” and “D” types are different mixtures of Eimeria species; the “T” type is for turkeys. Coccivac® is produced by Schering Plough Animal Health. More information about vaccinating against Coccidiosis can be found in ThePoultrySite's online CocciForum.
  
  
• Immucox®: This vaccine was developed in Canada by Vetech Laboratories. It is distributed by Wingo.
  
  
• Advent®: This vaccine was recently developed in the U.S. by Viridus Animal Health. It is marketed as having more viable oocysts (truly sporulated oocysts that can cause immunity) than other vaccines.

The vaccines above can actually cause some lesions and occurrence of coccidiosis in birds because they are not “attenuated” or weakened in some way. It is a controlled occurrence, but it may be necessary to treat for secondary gut disease, using antibiotics or alternatives such as probiotics. In contrast, coccidiosis vaccines used in Europe are attenuated. They are altered because the coccidia used in the vaccine are designed to mature quickly and have a short (“precocious”) life cycle and low fertility. They are not pathogenic – disease-causing – and are more costly to produce than the nonattenuated vaccines. They include Paracox®, Livacox®, and Viracox® which are marketed in other countries but not currently in the U.S.

More types of vaccines are likely to be developed, because the government approval process is much cheaper for vaccines than for anticoccidial drugs.

Since immunity is species-specific, anticoccidial vaccines include mixtures of species of Eimeria that affect chickens. It is especially important to include the three types that cause the most damage in chickens: Eimeria acervulina, Eimeria maxima, and Eimeria tenella.

Using Vaccines

Birds need good protection by the time they are three weeks old, so vaccines should be given at the hatchery or by one week.

• Spray cabinets: These are used at hatcheries on day-old chicks and may include a dye to indicate application. This is the most uniform method of application, resulting in 90 to 95 percent of chicks exposed to the vaccine. (Chapman, 2000)
• Edible gel: Gel pucks are placed in transport crates or on the floor of the house when the chicks arrive. The gel is brightly colored to attract the attention of the chicks. Immucox ® is administered in this form.
• Feed spray: Vaccines are mixed with water in a garden pressure-sprayer and sprayed on a 24-hour supply of feed. Advent® is either sprayed on the feed in this manner or applied in a spray cabinet at the hatchery.
• Drinking water: The chicks should be slightly water-starved to encourage them to drink. Since oocysts are heavy and fall to the bottoms of drinkers, they are mixed with a suspension agent to keep them evenly distributed. (Chapman, 2000) This method can be used for older chicks. Vaccines cannot be given through proportioners or nipple drinkers.

To confirm the method of application, check the tag. For example, Coccivac® is given to turkey poults by spray cabinet at 1 day old; feed spray at 1 to 3 days old, and via drinking water from 3 to 14 days old.

It is important to apply vaccines uniformly to ensure the birds get equal exposure. If birds receive too much of a nonattenuated vaccine, the parasites can cause lesions. If attenuated vaccines are not given in adequate doses, the birds will be susceptible to field strains of the coccidia. (Chapman, 2000)

The environment must allow the oocysts to sporulate, since the goal of vaccination is to introduce the parasite in small numbers. Litter should be damp but not wet. (Chapman, 2000) After vaccination, birds excrete fresh oocysts onto the litter. Birds then eat these (second cycle) oocysts. (Chapman, 2000) Two cycles of replication are needed for good protection.

Vaccines are usually sold only in large amounts. Advent is sold in 1,000-dose vials that cost about $13.50 each and must be purchased in boxes of 10 vials per box. Immucox can be purchased in smaller amounts. A tube of gel costs about $70 and has 28 “slices.” Each slice serves 100 birds. Half tubes can also be purchased for about $35.

Since the vaccines contain live oocysts, they should not be frozen. Birds need access to their droppings in order for the vaccine to work, since oocysts must be reingested. Vaccines are not effective for birds raised in batteries or cages with wire floors.

Vaccines have been used for some time to provide immunity for broiler breeders and commercial egg layers, but there is less use in broilers.

Vaccine boosters are not normally given. Broilers usually have a short life and do not need boosters. Longer-lived birds like layers are constantly re-exposed to coccidia, so immunity is topped off constantly.

Do not give drugs and vaccines to the same flock – they are opposed to each other.

If your flock is raised under intensive conditions, you will eventually need to vaccinate or use drugs. Tips for using vaccines in large-scale production are provided below. Although most large poultry companies work with their veterinarians on health issues, these tips will be useful.