Two Vaccines Prove Not Immune to the Vagaries of Fate

Vaccines are supposed to be a traveler’s ally, guarding against diseases that lurk in exotic locales or even at home.

But two recent developments prove vaccines aren’t foolproof. In December, several lots of Vaqta, a vaccine to prevent the viral liver infection hepatitis A, were voluntarily recalled by the manufacturer, which feared the vaccine didn’t protect patients adequately. And late last month, the manufacturer removed from the market the only vaccine available in the U.S. that protects against Lyme disease.

Even so, with a little know-how, travelers can still protect themselves against both diseases.

In all, 40 lots of Vaqta, all single-dose syringes, were recalled because their levels of antigen--a substance that stimulates the production of antibodies--were insufficient, said Art Kaufman, a spokesman for Merck & Co., which makes the vaccine. Consumers who may have received doses from the recalled lots would have been vaccinated with the adult dose after May 29, 2001, and with the pediatric or teen dose after June 16, 1999. (Vaqta is administered in one primary dose and one booster.) Merck has contacted physicians.

Those who may have been vaccinated with an affected lot should consult their doctor. If you were given a vaccine from a recalled lot and your doctor decides to do a blood test to see whether you are adequately protected against hepatitis A, Merck will cover the cost of the test, Kaufman said. If the doctor thinks you need another vaccination, Merck will also cover the cost of the vaccine, he said.

Merck is halting production of the vaccine in syringes until the manufacturing process is improved, Kaufman said, and will still supply Vaqta in vials, which have had no production problems.

Hepatitis A is spread by contaminated food and drink and is a problem in developing countries, where sanitation can be poor. Outbreaks also occur in the U.S. In 1997 more than 200 schoolchildren, most of them in Michigan, contracted the disease after eating tainted strawberries, according to the federal Centers for Disease Control and Prevention.

Symptoms can include fever, loss of appetite and abdominal discomfort, followed by jaundice. The disease can last from a few weeks to several months. To prevent it, travelers, especially if they are not vaccinated, are urged to avoid food that might be contaminated--raw vegetables, fruits and fruit juices, milk products and shellfish are often implicated in outbreaks--and avoid drinking water and beverages containing ice in areas of poor sanitation. There is no specific treatment, just supportive care such as a nutritious diet and plenty of rest.

Soon after the Vaqta recall, GlaxoSmithKline in late February pulled its Lyme disease vaccine, Lymerix, off the market, citing poor demand. On the market since 1999, Lymerix was the only vaccine for Lyme disease available here.

Doctors had observed the condition for years but didn’t identify it as Lyme disease until a cluster of cases occurred in 1977 in Lyme, Conn. The illness, which is spread to humans through the bite of deer ticks infected with the bacterium Borrelia burgdorferi, is now found in the Northeast, the mid-Atlantic and the north-central part of the country, as well as in some northwestern California counties, according to the CDC.

The manufacturer’s withdrawal of Lymerix came as no surprise--and often as a relief--to Lyme disease organizations. “We’ve been working to get it off the market,” said Chris Malinowski, a spokesman for the Lyme Disease Foundation. The manufacturer has been the target of several lawsuits from consumers who say the vaccine left them with neurologic or joint disease or inflammation of heart muscle tissue. Malinowski says his group has also received reports from vaccinated patients complaining of “brain fog” and sensitivity to light and sound.

GlaxoSmithKline spokeswoman Ramona DuBose would not say how many lawsuits have been filed, and emphasized that the vaccine was withdrawn only because of low demand.

After evaluating the 905 adverse reports received after a total of 1.4 million doses were given, CDC researchers concluded in a report published last month that most of the adverse reactions did not differ from what was reported in clinical trials, which were not judged significant enough to prevent marketing approval.

One exception was the 22 hypersensitivity reactions reported. These ranged from hives to difficulty breathing, which are typical symptoms of an allergic reaction, said Dr. Ned Hayes, medical epidemiologist with the CDC Lyme disease branch. But it could not be proved that these reactions were caused by the vaccine.

Symptoms of Lyme disease include a bull’s-eye rash, fever, headache and fatigue. Antibiotics are used to treat the illness; if untreated, it can become severe or disabling, according to the CDC.

Travelers can still guard against Lyme disease. The CDC suggests wearing pants and long-sleeved shirts (in light colors so ticks show up more easily) and using insect repellents containing DEET (N, N-diethyl-meta-toluamide).

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Healthy Traveler appears twice a month. The writer can be reached at kathleendoheny@earthlink.net.