Adele and Charles Sands cherish their daily hike in Oregon Ridge Park. But as the vegetation has grown more lush, the Timonium couple has become increasingly apprehensive about the ticks they find clinging to their dog, Samantha. Although the Australian shepherd has had shots to prevent Lyme disease for several years, the Sandses recently joined the first wave of humans to try vaccination as protection from the tick-borne illness.
Adele Sands has already had a brush with the infection. About a year ago, she developed a circular rash that looked suspiciously like the classic bull's-eye rash of Lyme disease, a bacterial infection that can invade different systems of the body. Her physician prescribed oral antibiotics, the usual treatment for early stages of the infection, and Sands suffered no further symptoms.
But the experience left her shaken. In addition to a rash, early indications of Lyme's disease can include fatigue, chills, fevers and joint pain. Untreated, it can cause numbness, arthritis, paralysis, irregular heartbeat and, in rare cases, death.
When she learned the U.S. Food and Drug Administration had approved LYMErix a few months ago, Sands was ready to try it.
"The alternative to not taking the vaccine was not pleasant," she says. "We thought, 'Let's give ourselves an edge.' "
The new vaccine does not guarantee immunity to Lyme. Given in three shots over the course of a year, LYMErix is judged to be only 78 percent effective. So far, the Sandses have each had two shots, which confers about 50 percent protection.
Injections are expensive: Each one can cost from $65 to $100 at a doctor's office, says Rob Stoltz, an internist at Greater Baltimore Medical Center who has given the vaccine to roughly 75 people, including the Sandses, during the last few months.
Although the clinical trials for the vaccine tested only people aged 15 to 70, Stoltz feels comfortable giving it to older patients -- the Sandses are in their early 70s -- who spend a lot of time in areas with many ticks.
Most of the reported cases of Lyme disease, however, are adults between 30 and 59 and children. Results from the first study of LYMErix's effects on children 4 to 15 in age should be available later this year, according to a spokesperson for SmithKline Beecham, the drug's manufacturer.
At present, the national centers for disease control and prevention do not recommend the vaccine for children, pregnant women, people who live, work or re-create in areas that are at low risk for deer ticks, and for people who have treatment-resistant Lyme arthritis.
LYMErix is the first vaccine to work by killing an infectious agent while it is still outside the human body. The drug actually enters the tick while it is feeding upon human blood and kills the bacteria, a spirochete, in the insect's stomach before it is able to inject it into its host.
Because the spirochete never enters the human body, however, it doesn't provoke the body's natural defenses into manufacturing additional antibodies to fight it. Researchers believe people who are vaccinated will need booster shots of the vaccine to maintain their level of protection.
Side effects
Although no serious adverse side-effects have been observed from taking the vaccine, someone could theoretically develop an arthritis-like reaction to the antibodies in it, researchers say.
And physicians like Charles Hale, chief of infectious diseases at GBMC, say they may prescribe the vaccine more frequently after learning more about its effects on a larger population. So far, physicians have given about 700,000 doses of the vaccine, according to SmithKline Beecham.
"I've never seen any side effects. ... A small percentage of people might get a little local pain [at the site of the injection] or have flu-like symptoms for a day or two," Rob Stoltz says. "If you're an outdoor person at all, why risk it?"
An avid golfer, Stoltz has taken the vaccine himself and also inoculated his wife, who spends a lot of time in their Baltimore County garden.
There were 659 confirmed cases of Lyme disease last year in Maryland, an increase of nearly 33 percent from the previous year. Nationwide, 18,000 cases were diagnosed, most from states along the northeastern and mid-Atlantic seaboard and from the upper north-central region of the country.
Health officials warn that the mildness of the past winter may increase the incidence of Lyme disease as well as such tick-borne diseases as erlichiosis, a parasite infection of white blood cells that can be fatal.
"It appears tick numbers are way up -- even though last year was a record," says David Weld, executive director of the American Lyme Disease Foundation. "We feel the vaccine is another important protection tool by people in endemic areas. Someone who goes to a place like Nantucket or vacations on the shore along the northeast coast should consult with their physician about the possibility of getting the vaccine."
Take precautions
Even with the added protection of LYMErix, people who spend a lot of time outdoors should take the usual precautions to avoid ticks: Wear long pants tucked into shoes or socks, choose light-colored clothing that makes it easier to see ticks and use insect repellents containing DEET.
A number of types of ticks are common on the East Coast, but only deer ticks carry Lyme. They contract the bacteria from feeding on white-tailed deer or white-footed mice. One-fourth to one-half of deer ticks in Lyme-infested areas carry the disease, researchers say. To pass it to a human, an infected tick must feed on its human host for about 36 hours.
Most people who are bitten by a deer tick never feel it. Much smaller than dog ticks, adult deer ticks are hardly bigger than a capital O until they become engorged with blood. Nymphs, which tend to feed in June and July, are about the size of a pinhead.
How severely someone gets Lyme usually depends on how soon it is treated. Early symptoms vary, but most people will get a red rash, usually near the bite. The rash may appear as early as two days after infection or not appear for several months. It often has a bull's-eye appearance, but may also be shaped like a ring, triangle, oval or long thin ragged line. In African-Americans and other people of color, the rash can resemble a bruise.
It is usually not itchy or painful, feels warm to the touch and eventually disappears -- it can last from a week to a month. Sometimes it is so faint that it is hard to detect.
A person needn't go into the woods to be at risk for Lyme disease, health officials warn. Animals and birds carry deer ticks into back yards, picnic areas and golf courses.
During the summer months, daily tick checks can prove essential to preventing the disease. To remove a tick, use blunt-tip fine-point tweezers to grasp the tick where its mouth parts enter the skin. Tug gently until it releases its hold. Wipe the area with antiseptic or soap and water.
Grabbing at a tick -- or pricking, burning or squeezing it -- can cause it to regurgitate bacteria into its host.
LYMErix vaccine
Given in three shots over the course of a year, LYMErix is judged to be only 78 percent effective.
At present, the National Centers for Disease Control and prevention do not recommend the vaccine for children; pregnant women; people who live, work or play in areas that are at low risk for deer ticks; and people who have treatment- resistant Lyme arthritis.
Pub Date: 06/20/99