What is a recombinant vaccine, and how does it work?

Question: What is a recombinant vaccine, and how does it work?

There has been a lot of discussion in recent years about vaccination protocol for pets and the safety and efficacy of animal vaccines. The focus of this FAQ cannot cover all of these issues, but will focus on a newer type of vacine class called recombinant vaccines. To learn more about diseases and what vaccinations are available, please see the vaccinations section of this site.

Answer: Traditional vaccines are made by killing or weakening the disease organism (virus, bacteria, fungus, etc.) and injecting it into the patient to stimulate the patient's immune system to produce antibodies against the disease. Then, in theory, if the patient came in natural contact with the disease organism, the body's immune system would mount a response and prevent illness in the patient.

Recombinant vaccines are created by utilizing bacteria or yeast to produce large quantities of a single viral or bacterial protein. This protein is then purified and injected into the patient, and the patient's immune system makes antibodies to the disease agent's protein, protecting the patient from natural disease.

Advantages of the recombinant vaccine technology are that there is virtually no chance of the host becoming ill from the agent, since it is just a single protein, not the organism itself. Traditional vaccine risks come from the organism not being totally weakened (attenuated) or a reversion to a virulent (disease causing) form. Another advantage of a recombinant vaccine is that it does not need an adjuvant. An adjuvant is an agent that stimulates (irritates) the immune system to find and react to the vaccine agent. Some adjuvants have been implicated in causing cancer in some animals over time.

Please speak to your veterinarian if you have questions or concerns regarding your pet's vaccination protocol or scheduling.