THE PHYSICIAN AND SPORTSMEDICINE - VOL 27 - NO. 4 - APRIL 99
Lyme Disease Vaccination: Who Needs It? How Effective?
The first Lyme disease vaccine was approved in December 192021, and now that tick season is near, physicians are likely to field questions about the vaccine from anxious patients who have seen it advertised.
The vaccine (Lymerix, SmithKline Beecham Pharmaceuticals, Philadelphia) was approved for people aged 15 to 70 who are at risk for Lyme disease. It is given in three doses spread over a year. In clinical trials, the vaccine was 50% effective after two doses and 78% effective after three doses, according to a report from the Centers for Disease Control and Prevention (CDC) (1).
Brian S. Schwartz, MD, associate professor and director of the Division of Occupational and Environmental Health at Johns Hopkins School of Public Health in Baltimore, says the vaccine combines a single recombinant protein from the infective organism with an adjuvant that stimulates the immune system to produce an antibody. "The antibody in the human's blood kills Lyme disease bacteria in the gut of the tick after the tick feeds," says Schwartz, who has researched the risk in outdoor workers for 10 years (2) and sees Lyme disease patients on referral.
A second Lyme disease vaccine is awaiting US Food and Drug Administration (FDA) approval. ImuLyme (Pasteur Mérieux Connaught USA, Swiftwater, Pennsylvania) is based on the same recombinant protein as Lymerix, according to Schwartz.
Who Should Be Vaccinated?
Clinical opinions vary on who should receive the vaccine. John Meyerhoff, MD, clinical scholar in rheumatology at Sinai Hospital in Baltimore, says he recommends the vaccine to anyone who lives in or travels to endemic areas: from Maryland up the Atlantic coast, Wisconsin and Minnesota, and the Pacific Northwest.
Schwartz recommends the vaccine for those who live in an endemic area and don't feel they can adequately protect themselves from tick bites. "But I'm not sure people who are diligent need the vaccine," he says.
The vaccine was not tested in people younger than 15 or older than 70, pregnant women, and people with rheumatic arthritis or certain heart conditions, according to the FDA. Safety data for those groups therefore are limited.
Meyerhoff says patient risk factors might influence whether or not insurance companies or managed care organizations will pay for the vaccine, which costs about $200 for the series. Schwartz says insurance companies may wait until the Advisory Committee on Immunization Practices, a division of the CDC, issues its report. Barbara Reynolds, a spokesperson for the CDC, said the committee is drafting some recommendations that will appear in an upcoming issue of Morbidity & Mortality Weekly Report. "The recommendations will be based on individual risk and geographic risk," she says.
Protection Takes Time
The vaccine is given in three doses: at 0, 1, and 12 months. It can cause pain at the injection site and possibly a fever. Researchers don't know how long protection lasts, and boosters may be needed.
Pharmaceutical companies are working to improve the dosing schedules so that patients are fully protected faster. "It's also an issue of patient compliance—the longer the time [between doses], the smaller the proportion of people who will finish the series," Schwartz says. Meyerhoff, who wrote the first review article on Lyme disease (3), says physicians can boost patient compliance by developing a "tickle" file, keeping a log of who has received the vaccine, or emphasizing the patient's responsibility for follow-up. He notes that the Lyme vaccine is given on the same schedule as the hepatitis B vaccine.
Patients need to know that they are never fully protected by the vaccine, and that protection doesn't reach 78% until they have received all three doses a year after their first dose. That means patients shouldn't abandon the usual Lyme disease preventive measures, which include wearing long pants and other protective clothing, wearing tick repellent, checking for ticks, and knowing tick removal methods. Another reason to continue preventive measures is that the vaccine does not prevent other tick-borne illnesses such as ehrlichiosis, babesiosis, and Rocky Mountain spotted fever.
The lag in protection could cloud the clinical picture if a recently vaccinated patient has Lyme disease symptoms, Schwartz says. "The vaccine will produce a positive blood test on the first-stage ELISA test, and it does produce one band on the Western blot," he says. "That might make Lyme disease trickier to diagnose." (See "New In-Office Test Speeds Lyme Disease Detection," below.)
New In-Office Test Speeds Lyme Disease Detection
In February the US Food and Drug Administration (FDA) approved a new blood test for Lyme disease that can produce initial results in an hour. The test will enable physicians to make a diagnosis without sending the sample to a lab and to start antibiotic treatment sooner, according to an FDA press release.
The Centers for Disease Control and Prevention recommends a two-step procedure for Lyme disease testing: A positive ELISA test should be confirmed by a Western blot test. The new test, Pre Vue B. burgdorferi Antibody Detection Assay (Chembio Diagnostic Systems, Medford, New York) is simply a quicker version of the ELISA test, says John Meyerhoff, MD, clinical scholar in rheumatology at Sinai Hospital in Baltimore.
In its press release the FDA said approval of the test was based on studies that showed a 3% false-positive rate, similar to the rate for other tests for Lyme disease.
Meyerhoff says the availability of a quicker, easier test for Lyme disease may raise some problems. He notes that the tests are "reasonably" sensitive and specific, but that more false-positives could skew the results if physicians are testing patients with a low likelihood of having Lyme disease. "The test is only as good as the people who are using it, and physicians need to learn to use the tests selectively," he says. Patients who have the classic bull's-eye skin rash don't need the test because Lyme disease is highly likely, he says, and the tests are negative in patients who have been infected in the previous 2 to 3 weeks.
News From the AAOS Annual Meeting
The 66th annual meeting of the American Academy of Orthopaedic Surgeons (AAOS) was held in February in Anaheim, California. Here are some highlights of the meeting as described in press releases and news reports from the AAOS.
NBA Team Physicians Cope With Lockout Fallout
Settlement of the National Basketball Association (NBA) lockout in early January meant that players—some out of shape and overweight—were thrust into an intense 2-week training camp. Then they embarked on a rigorous, condensed schedule that often requires teams to play three games in three nights.
What are NBA team physicians' impressions of the medical consequences of the lockout and schedule, and what are the teams doing to keep players healthy and on the court?
Sheldon Burns, MD, medical director, Minnesota Timberwolves:
Glenn Perry, MD, team physician, Charlotte Hornets, president of the NBA Team Physicians Society:
Harlan Selesnick, MD, team physician, Miami Heat:
Does Smokeless Tobacco Improve Performance?
Researchers investigated the effects of smokeless tobacco on reaction time and strength in Division III college athletes. The researchers compared 20 athletes who used smokeless tobacco with 20 who did not use any form of tobacco (the tobacco users were tested during use and while abstaining). The results showed that smokeless tobacco had no effect on reaction time but may have impaired strength.
Let Patients Know About Fitness Week
FDA Urges Supplement Recall
According to an FDA press release, products containing GBL purportedly build muscles, improve physical performance, enhance sex, reduce stress, and induce sleep. Brand names include Renewtrient, Revivarant, Blue Nitro, GH Revitalizer, Gamma G, and Remforce. Sold in liquid and powder forms, the products are marketed on the Web, in health food stores, and in some gyms and fitness centers.
When taken orally, GBL converts to gamma hydroxybutyrate, a drug currently under study for the treatment of narcolepsy. GBL-related products have been associated with at least 55 adverse events, including one death, according to the FDA. In 19 cases, consumers became unconscious or comatose. Other reported effects include seizures, vomiting, slow breathing, and bradycardia.
Dietary Supplement Data on the Web
Study Sheds New Light on Women's ACL Injuries
Incidence rates per 1,000 exposures were 0.0055 in men and 0.0135 in women, giving women a relative risk of 2.44. Gwinn noted that the higher risk in women has been attributed to several intrinsic and extrinsic factors, but that this study suggests intrinsic causes because female and male midshipmen met athletic competence standards upon admission and had the same training programs and facilities while at the academy. "This is of particular concern and deserves further study," Gwinn said.