Jan. 18, 2000 (Boston) -- A vaccine designed to protect people against the tick-borne illness Lyme disease may be as effective and well-tolerated in children as it is in teen-agers and adults. But even if the vaccine is eventually approved by the FDA for the under-15 set, should every child get it? Probably not, say leading pediatricians interviewed by WebMD.
"I think it's up to individual patients and physicians to decide, but this is not a huge scourge of humanity -- we're not preventing a fatal illness like polio," says Eugene D. Shapiro, MD, professor of pediatrics and epidemiology at Yale University School of Medicine in New Haven, Conn., in an interview with WebMD.
The old chestnut about an ounce of prevention being worth a pound of cure certainly holds true for Lyme disease, which, according to the CDC, accounts for more than the 95% of all insect- or animal-borne illness in the U.S. But although a recently approved vaccine (LYMErix) offers reasonably good protection against infection with the organism that causes Lyme disease, the best defense is to avoid getting bitten in the first place, say members of an American Academy of Pediatrics (AAP) advisory panel in the January issue of Pediatrics.
Lyme disease -- so named because some of the earliest identified cases occurred in the area around Old Lyme, Conn. -- can occur when a person is bitten by a common deer tick that is infected with a corkscrew-shaped bacterium called Borrelia burgdorferi. Infection usually begins with a red rash that spreads like a bulls-eye around the bite site. When caught early, the infection readily responds to treatment with antibiotics, but if it is left untreated or is misdiagnosed, it can cause muscle pain and headaches, fever, and painful swelling and inflammation of the large joints (Lyme arthritis). In advanced cases, infections can cause disabling symptoms in the heart and brain.
Most cases of Lyme disease in the U.S. are clustered in New England and the mid-Atlantic states and in the upper reaches of the Mississippi River. Deer ticks tend to favor wooded areas, high grasses, marshes, and beaches. But even in areas where the disease is common, the overall risk of infection following a deer tick bite is still 1 in 50, researchers estimate.
The AAP panel recommends that people take commonsense measures against infection, such as avoiding tick-infested areas, using protective clothing (pants tucked into socks, long-sleeved shirts), and using an insect repellent containing the chemical DEET (n,n-diethyl-m-toluamide) on the skin. A different type of repellent designed for application on clothing only and containing the chemical permethrin has also been shown to be highly effective.
The panel opposes routine use of antibiotics in people who have been bitten by a tick but have not been positively diagnosed with Lyme disease, saying that the practice "is of unproven value and is associated with potential risks and costs."
The AAP recommendations also say that the Lyme disease vaccine can be considered in teens aged 15 and over who live, work, or play in areas of high or moderate risk, or those who stay in such places during the peak transmission season of spring and whose activities result in frequent or prolonged exposure (i.e. lawn and garden work, beach-combing, boating, etc.).
But what about children between the ages of 5 and 15? In a study of 250 children reported in Pediatrics in November 1999, Henry M. Feder, MD, and others found that the vaccineappeared to be well tolerated and produced a high level of antibodies to the bacteria in 99% of the children who received the vaccine. The presence of the antibodies suggests that the children's immune systems had been primed to fight off Lyme disease.
"The preliminary feeling with the vaccine is that the side effects in children are, if anything, no more than in adults and probably less, and the immune response is at least as good, but probably better," says Feder, professor of pediatrics at Connecticut Children's Medical Center and professor of family medicine at the University of Connecticut Health Center in Farmington, in an interview with WebMD.
Feder says that because the vaccine is "not perfect" at protecting patients against infection, "it's very important that whatever people try to do to avoid Lyme disease, they should keep doing. I think that's one of the things that worries some physicians about the Lyme vaccine -- the idea that 'Oh, now that I've had the vaccine, I don't have to be careful [about exposure to ticks].'"
Shapiro tells WebMD that he agrees with the panel's recommendations for more study of the risks vs. benefits of the vaccine in children. "Perhaps more relevant is the fact that Lyme disease is generally a benign illness, so I would question the need for the vaccine as a routine," he says. "The recommendation of the expert panel is that its use be considered for people who are at high risk, but most kids are not at high risk, and in general it's an easily treated illness, so there's no real need for immunization."
Among the concerns about the vaccine, Shapiro notes, are the multiple doses required (three injections over as many months), frequent reports of pain and swelling at the injection site, and a high number of false-positive antibody tests in patients who have received the vaccine. False-positive antibody results could cause physicians to mistakenly believe that a patient has Lyme disease and overlook other possible causes of a patient's symptoms.
"I don't routinely recommend [the vaccine] to anyone," Shapiro says.