Small Steps Against Big Diseases

In suburbs and rural areas, summer is Lyme-disease season, prompting the flurry of instructions now issuing forth from doctors' offices on how to avoid the illness. It's wise to pay attention: the symptoms can range from joint pain and lethargy in mild cases to debilitating arthritis and even heart damage. But thwarting Lyme disease is not so easy, as anyone knows who has ever searched for the poppy seed-size tick that carries it, or for its unmistakable rash -- which sometimes never appears at all. Tests sometimes don't reveal an infection, and symptoms may not show up for months -- and when they finally do, antibiotics don't always work.

But medical researchers at Yale and Harvard say they have come up with a vaccine that appears to protect against Lyme disease -- in mice, at least. Not only that: when infected ticks bit vaccinated mice in the lab, the disease bacteria inside the ticks were killed as well. That was totally unexpected; if it works the same way in humans, the vaccine could lead not only to the prevention of Lyme disease in humans but to its complete elimination in the wild.

There was also progress last week on another vaccine; the step forward may have been smaller, but the disease much more widespread and deadly. Researchers in the U.S. and France presented a report in the journal Science on a breakthrough in creating a vaccination against aids. The scientists had already proved that chimps could be protected by an experimental vaccine, but only from the aids virus that swims in the fluids outside cells. The virus found within cells is infectious too, and the new results prove that the immunization works on this variety as well. No one knows exactly how the process works, which means it might not work the same way in humans, and the vaccination regime -- multiple shots over several months, and no guarantee the protection is long lasting -- makes it inconvenient, especially in Third World countries where medical services are poor. But any progress at all toward turning AIDS from a killer into a nuisance is good news.