PREGNANT PAUSE

The Baltimore Sun

It sounds like some medieval baby-killer that must have disappeared when husbands first began boiling water as their wives went into labor.

But 25 percent of pregnant women in the United States carry a common, potentially deadly bacterium called group B streptococcus (or GBS) that can infect their babies during childbirth or soon after.

Although doctors frequently administer antibiotics during labor to prevent them, GBS infections kill or injure several thousand babies each year - within hours or weeks of their birth.

Advocates say vaccinating pregnant women could avert those tragedies - unfortunately, no vaccine for GBS exists. Nor is any drug company likely to develop one, they say, and most doctors probably wouldn't use one if it were available.

"Just forget it. It ain't gonna happen," said Dr. Carol J. Baker, a GBS expert and co-director of the Texas Children's Vaccine Center, who spoke recently to colleagues in Baltimore for the 10th annual Conference on Vaccine Research. "We could make these numbers 100 times worse in terms of the disease burden and death rates, and it ain't gonna happen. It's about lawyers."

The debate over vaccinating pregnant women goes well beyond GBS. On one hand, researchers say this may be the best time to protect mother and infant against a variety of diseases, from flu to whooping cough.

But drug companies are less than enthusiastic about developing vaccines with small markets that could open them to ruinous lawsuits if a baby suffers a birth defect or complication - for any reason. Many doctors feel the same way about prescribing vaccines to pregnant women - even safe ones. So newborn deaths and GBS brain injuries persist.

One such infection caught little Max Royka, who was 6 weeks old and thriving at home in Nashville, Tenn., when the group B strep bacteria suddenly overwhelmed his system.

His mother had tested negative for the bacteria, so he probably had not been infected at birth - but he began his life with no immunity to the bacteria and paid a terrible price.

"He was fine one minute, and literally a couple of minutes later he was pale and whimpering," his mother, Jill Royka, 36, recalls. Within hours he was in a coma. "He was completely consumed by this germ."

After 13 days in intensive care and seven weeks of hospital treatment for meningitis, Max was left permanently brain-injured.

Now 6, he is legally blind and unable to speak or walk normally. He must be fed and hydrated through a tube. He also takes seven different medicines for epilepsy, behavioral problems such as head-banging and hair-pulling, and for diabetes insipidus, which causes frequent urination.

"It is a daily struggle," Jill Royka said.

The same fear of litigation is making doctors wary of vaccinating pregnant women against whooping cough, or pertussis - a rapidly growing threat in the United States.

More than 25,000 Americans came down with whooping cough in 2004 - double the count in 2003. Between 1997 and 2000, some 62 Americans died from complications of whooping cough, according to the U.S. Centers for Disease Control and Prevention. Fifty-six of those were younger than 6 months.

Just as disturbing: Despite clear government approval for it, doctors vaccinate only 12 percent of pregnant women against influenza, an illness that causes high rates of complications during pregnancy.

"At most, about half of OB-GYNs will provide [flu] vaccine," said Dr. Kathryn M. Edwards, professor of pediatrics at the Vanderbilt University Medical Center in Nashville. Another 28 percent will refer their patients for vaccination elsewhere, while 24 percent make no referral at all. "This is a major issue."

The flu vaccine should not be a concern, experts say. "We have good data that the inactivated [flu] vaccine is safe in pregnancy. It's not associated with any risk of adverse outcomes," said Dr. Neal A. Halsey, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health.

But some doctors note that it's easy for parents to look back and find something to blame for abnormalities, which occur once in 100 births and for myriad reasons unrelated to vaccinations.

"People tend to assume that anything bad that happens - all congenital abnormalities - might have been caused by something administered during pregnancy," Halsey said.

Vaccines have come under increasing suspicion since the late 1980s, when some parents and researchers began to associate childhood immunizations with an increase in autism diagnoses.

The CDC says there is insufficient evidence to support such a conclusion. But the number of autism-related claims against drugmakers through the National Vaccine Injury Compensation Program has nevertheless soared into the thousands.

For drugmakers, the issue goes beyond fear of litigation, according to Alan Goldhammer, deputy vice president of the Pharmaceutical Research and Manufacturers of America.

First, he said, ethical concerns make it "extremely unlikely" that the Food and Drug Administration would approve clinical vaccine trials on pregnant women. Nor are university ethical review boards likely to endorse them.

Also, Goldhammer said, the market for a one-time vaccine for women is small. "There is a real concern on the part of pharmaceutical companies as to whether there would be a sufficient return on investment to engage in the considerable amount of work required to develop a vaccine."

Still, vaccination during pregnancy is saving lives elsewhere. A United Nations campaign to vaccinate pregnant women (and encourage "clean deliveries" in a sanitary environment) in 58 countries reduced newborn tetanus deaths from 787,000 in 1987 to 150,000 in 2004, according to U.N. figures.

"A baby is a wonderful parasite," said Vanderbilt's Edwards. Maternal antibodies developed in response to a vaccine begin to move across the placenta to the baby just 17 weeks after conception. By 33 weeks, the infant's antibody levels equal the mother's.

For Baker, the greatest potential to save babies' lives this way now lies with group B strep. First described in the 1930s, GBS is now the single most common cause of bloodstream infections and infectious disease deaths during the first month of life, she said.

Around the world, about 25 percent of humans carry it - men and women. We pass it around through sexual contact and "fecal-oral" exchange - failure to wash properly after using the bathroom.

Usually benign, GBS lives as "normal flora" in the digestive and genital tracts, Baker said, causing "no symptoms, no problems."

None, that is, until a chronic illness weakens our immune defenses, or in infancy, when our immune system is weak because of its immaturity. "The chances of serious bacterial infection in the first month are greater that at any other time of life," Baker said.

After an early rupture of the amniotic membranes, and then during delivery, a baby is exposed to all the bacteria living in its mother's vagina.

All but 1 percent or 2 percent of babies emerge unscathed. But of those who acquire an infection, 95 percent fall ill within the first 24 hours of life. About 3,000 of these early-onset infections occur each year, Baker said, and half of those newborns develop neurological symptoms, including meningitis. At least 200 die.

Another 3,000 infants a year, like Max Royka, fall ill a week to three months after delivery. Doctors think these infections likely occur postnatally, from contact with a carrier, perhaps a family member.

Baker said one-third of late-onset victims such as Max develop meningitis, and half of those will be permanently brain-damaged. About 90 die each year, Baker said.

To avoid such tragedies, the American College of Obstetricians and Gynecologists recommends that all women who test positive for GBS after 35 weeks of pregnancy receive intravenous antibiotics during labor to reduce the threat.

Jill Royka tested negative for GBS while pregnant with Max, so she received no antibiotics. Max was stricken weeks later. With her second delivery, Royka still tested negative for GBS, but she insisted on receiving antibiotics, just in case. Her younger son, Luke, now 3, is healthy.

Antibiotics given during labor have reduced the incidence of early-onset GBS infections by 80 percent in the past decade, Baker said. But it's not a perfect solution. Many doctors don't like the idea, and sometimes the baby just arrives too quickly.

Nor have antibiotics given during labor had any impact on the incidence of late-onset GBS infections such as Max Royka's. That's why Baker is so keen on vaccines.

The vaccine would not be hard to make, Baker said. But after advocating for a decade without success, she is considering other possibilities, including the routine vaccination of adolescent girls and women before they conceive.

Many are already getting meningitis shots and boosters against whooping cough, tetanus and diphtheria. And the CDC now recommends that all females ages 11 to 26 receive a vaccination against the human papillomavirus (HPV) found to cause cervical cancer.

Baker believes drugmakers might sign on to the idea of a preconception GBS vaccine that could be offered along with these other immunizations. Physicians, too, may warm to the idea.

She said the CDC is encouraging more "preconception health visits," to inform women about coming medical and nutrition issues as they approach their child-bearing years, such as the need for folic acid in their diet to prevent a crippling birth defect called spina bifida.

Such preventive medicine is not something all gynecologists routinely do, she said. But requests for HPV shots may change that.

"I think that's going to change their behavior as physicians," she said. "They're going to be thinking about vaccinations, so it's not too great a leap to get them to think about other important vaccines."

frank.roylance@baltsun.com

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