An article yesterday incorrectly reported that the first Lyme disease vaccine for animals would be ready in two or three years. There is a vaccine now available for dogs. A vaccine for animals based on the work of Yale researchers will not be ready for two or three years. One for humans is said to be five to eight years away. (Published 10/27/90)

Yale scientists have developed the first practical candidate for a vaccine to protect humans and animals from the microscopic organism that causes Lyme disease.

A report in today's issue of the journal Science details the success of a vaccine that protected laboratory mice against the infection, which is the nation's most common tick-borne scourge and a cause of chronic arthritis, abnormal heart rhythms and extensive nerve damage in humans.

"We are very encouraged by our work," said Erol Fikrig of Yale University School of Medicine in New Haven, Conn. "We think we made real progress."

Fikrig and his colleagues at Yale believe a human vaccine will be available in five to eight years. A vaccine for pets and other animals should be ready in two to three years, the researchers said.

Virtually unknown a decade ago, Lyme disease has exploded from a medical curiosity to a worldwide health menace. Since the baffling illness surfaced in the town of Old Lyme, Conn., it has been reported from all but five states, as well as Britain, Australia and northern and eastern Europe.

The disease is spread by ticks, which carry a microscopic organism called Borrelia burgdorferi, named after National Institutes of Health researcher Willy Burgdorfer, who identified the corkscrew-shaped bacterium that causes the illness.

The bacterium usually causes a rash, muscle aches and a mild illness easily mistaken for the flu. Later symptoms can include a suite of skin, heart, joint and nervous system complications.

The work by Yale researchers first required the cloning of a gene that carries the code for a protein found on the surface membrane of the bacterium. Once the gene was cloned, the scientists used genetic engineering techniques to make a large quantity of the pure protein, which they then used in a vaccine that they injected into laboratory mice. In response to the vaccine, the mice's immune systems manufactured high levels of antibodies against the foreign protein. When challenged with injections of the Lyme disease bacteria, the vaccinated mice fought off the infection and were protected.

Fikrig said the Yale team is now testing the vaccine to see if it will protect mice against several dozen strains of the disease-producing microbes. Initial results, according to Fikrig, are encouraging. The vaccine already has protected the animals against three different strains.

The scientists soon plan to do safety studies in primates and, later, humans. Fikrig said the vaccine against Lyme disease probably would be administered much like one currently available against hepatitis B, an initial injection followed later by booster shots.