SALT LAKE CITY — Flu shots for pregnant women are a "public health priority,” according to authors of a large study being released Tuesday that found the vaccine confers a significant protection for newborns in the first six months of their lives.

University of Utah researchers analyzed the records of more than 245,000 infants born in Utah and found that babies whose mothers were vaccinated while pregnant had a 70 percent reduction in lab-confirmed flu cases and an 80 percent reduction in flu-related hospitalizations.

Despite the benefits, only 1 in 10 pregnant women were immunized during the nine-year period the study covered, according to researchers.

"Women are concerned about anything they do in pregnancy," said Dr. Julie Shakib, University of Utah assistant professor of pediatrics and the study's lead author. "But what they have to learn and understand is that not immunizing themselves against influenza during pregnancy can cause harm for their infant."

Of the 658 babies with lab-confirmed flu, 97 percent were born to moms who were not immunized, according to the study. And of those infants, 23 percent were hospitalized for flu-related conditions, researchers found.

Dr. Daniel Chappell, a family medicine doctor and pediatrician in Bountiful, said the results of the study are "not at all surprising."

Coverage rates were low before the 2009 flu epidemic, which was a wake-up call for many in the medical community, Chappell said. The strain that year — H1N1 — hit pregnant women particularly hard.

At the time, many OBGYNs did not consider the vaccine a necessity for pregnant women. And less than 3 percent of pregnant women in the database reported getting the immunization, according to the study.

Then researchers started noticing that pregnant women were being hospitalized and dying at far higher rates than the rest of the population.

Now the vast majority of the pregnant women in Chappell's practice get the flu vaccine, he said. Those who don't tend to be wary of vaccines in general.

"You talk about the risks versus the benefits," Chappell said. "In the case of vaccines, the benefits definitely outweigh the risks."

The Centers for Disease Control and Prevention, American Academy of Pediatrics and American Congress of Obstetricians and Gynecologists recommend maternal influenza immunizations.

Still, Chappell said, every doctor has patients who object to vaccines for strong religious or personal reasons.

"I try not to push it with them," Chappell said, although he added that he's had a number of patients who agreed to vaccines after spending several years with him as their pediatrician.

Pregnant women who get immunized aren’t just protecting themselves, Shakib said.

Flu in infants

All young children are at high risk of serious flu-related complications, according to the CDC, but children younger than 6 months are at the highest risk because they cannot be immunized.

Shakib said the consequences of getting the flu as an infant are "potentially devastating," with associated complications like pneumonia, dehydration, ear infections and — in rare cases — death. The CDC estimates that 20,000 children younger than 5 years old are hospitalized due to flu complications each year in the U.S.

Many of those trips to the hospital could be prevented if moms had received the flu vaccine during pregnancy, according to the study, when a mother's maternal antibodies are transferred to her unborn child through the placenta during pregnancy.

"It's a gift that the mother gives to her baby before the baby's even born," Shakib said.

Access

Another issue is access, according to Shakib. The study found that uninsured women, women with government insurance and women living in rural or frontier areas are less likely to report receiving the vaccine.

The influenza immunization coverage rate for pregnant women jumped from a low of 2.2 percent before the H1N1 pandemic to 21 percent during and after the pandemic, the study reports.

"However, those numbers aren't high enough," Shakib said.

She said researchers are working on solutions to increase the coverage rate for maternal immunizations, including better education for obstetricians and increasing access for patients.

The take-home message for moms, according to Shakib, is simple: "Get your flu shot during pregnancy," she said. "Get it as soon as it’s offered to you." Email: dchen@deseretnews.com Twitter: DaphneChen_

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