A vaccine against Lyme disease is given to mice to reduce the risk of this tick-borne disease, reports the Journal of Infectious Diseases.
Lyme disease, caused by the bacterium Borrelia burgdorferi, is a dangerous disease – it can damage joints and cause neurological problems. Every year in the USA, 300 people are diagnosed with Lyme disease. In 000, an effective vaccine was developed against it, but due to serious side effects in 1998 it had to be withdrawn from the market.
As the main reservoir of B. burgdorferi are mice, Maria Gomes-Solecki from the University of Tennessee in Memphis decided to act on them. She concluded that it was enough to immunize the mice and the ticks that sucked their blood would also become immune – thanks to the murine antibodies. As a result, bacteria could not live in mice or ticks, protecting humans.
The Gomes-Solecki team has succeeded in developing an edible vaccine that can be administered in the form of oat granules. The vaccine pellets were scattered over four areas of a meadow the size of a football field. Pellets without vaccine were sprinkled on three others. Where the vaccine was delivered, the percentage of ticks infected with Borrelia declined over time – after five years, it fell by 76%. As expected, the pellets without vaccine did not change the percentage of infected ticks.
Thomas Mather of the University of Rhode Island Tick Encounter Resource Center (USA) finds this concept good, though difficult to implement. As early as 1987, he himself experimented with cotton balls saturated with tickicide, which mice eagerly used to house their nests with. Unfortunately, not only mice are infected with Borrelia – larger mammals such as skunks and deer are also affected. However, according to Gomes-Solecki, vaccinating mice can significantly reduce the spread of Lyme disease without disturbing the balance of the ecosystem. The scientist believes that the ideal would be a vaccine that would work against many species of animals (PAP).