ASK DR. BAUGHAN                                                         January 15, 1999

LYME DISEASE VACCINE

Lyme disease is one of the diseases that has become a commonplace term in the past 20 years in the United States.  It was named for Lyme, Connecticut (something the Lyme Chamber of Commerce has not celebrated) where it was first isolated and identified.  It is caused by a bacteria with the awkward name of Borrelia burgdorferi, and is transmitted by the bite of a deer tick, a small tick no bigger than a comma, not the larger, more common dog tick.  The sneaky and frustrating features of the disease is that symptoms may show up weeks or months after a bite, and since the tick is so small, a person may not be aware of a tick bite.  The first symptoms may be malaise, acheyness, and a characteristic bull’s-eye rash.  The person may get better and only weeks to months later still develop joint pains, persistent fatigue or neurologic symptoms of numbness or weakness in the extremities.  A blood test may help diagnose the disease only after the person has been infected for a while, and the test is not always positive even then, and there can be false positive results as well.

Antibiotics can treat it very effectively in the early stages, but less well if it is not detected until months down the road.  Therefore, a vaccine for Lyme disease has been eagerly pursued and awaited.  Such a vaccine is being released this month or next under the brand name LYMErix by SmithKline Beecham Pharmaceuticals.  Now the questions arise: (1) How effective is it?  (2) Are there any risks? (3) Who should get it?

The vaccine requires 3 doses, and may need annual booster shots to work at all.  Initial studies gave the 3 doses over 12 months, but then it was found that giving them over a two month period worked just as well.  The immune system then took 2 more months before achieving the peak antibody response needed to protect against the disease.  The ticks are most likely to infect between April and the end of July, so the immunizations should optimally be complete by the end of February.  Even then, about 75% of people given the vaccine will have a protective antibody level.

In research studies to date, there were brief, mild to moderate side effects.  Some researchers have expressed theoretical concerns about a possible vaccine-induced arthritis in genetically susceptible patients, but so far none have been found.  It has not been tried on children under 15 or on pregnant women, so it is not presently recommended for them.

The vaccine will be most widely used in the parts of the country were Lyme disease is widespread, the Northeast from Massachusetts through Rhode Island, Connecticut, and New York down to Maryland, then in Wisconsin, Minnesota and northern California.  If you visit those areas, the value of the vaccine will depend on whether you visit during the peak epidemic times, April through July.  The Center of Disease Control found that treating early signs of Lyme disease with generic antibiotics could be just as cost-effective as vaccinating, and may still be necessary for those who show any symptoms, since the vaccine may not work for 25% of those vaccinated.

The New Hampshire Office of Community and Public Health acknowledged that they do not have very reliable statistics on how widespread Lyme disease is in New Hampshire, but is conducting a study this year.  We know that deer ticks exist throughout the state, but how many carry the bacteria this far north is harder to study.  They could not yet give any hard guidelines on who should receive the vaccine; they recommended a case by case decision between each doctor and each patient.

So, vaccine or no vaccine, continue to take tick precautions.  Wear light-colored clothes so you can see the ticks more easily.  Tuck pants into socks to keep them from getting under clothes.  The ticks must be attached for almost 24 hours to spread the bacteria, so daily “skin checks” can be very helpful if you spend time outdoors.  Finally, use tick repellent, permethrins.