Roll up your sleeves, moms-to-be. It’s flu-shot season, and new research released Monday shows that babies whose mothers were vaccinated during pregnancy were less likely to get the flu or to be hospitalized with respiratory illnesses in their first six months of life.At risk is the baby who’s born during cold and flu season when people are cloistered indoors, sneezing and coughing on one another. Infants can’t be vaccinated against flu until their six-month birthday, yet young kids are at greater risk of flu-related complications. Although babies younger than six months don’t seem to come down with the flu as often as older babies, in severe flu seasons, death rates among infants younger than six months are greater than those associated with older babies. (More on Time.com: 5 Pregnancy Taboos Explained (or Debunked))
“Because they’re small and their lungs are small and their immune systems are immature, they’re quite vulnerable,” says lead researcher Kate O’Brien, a pediatric infectious diseases specialist at the Johns Hopkins Bloomberg School of Public Health. “Very vulnerable infants don’t have a good vaccination strategy.”
But now they do: their vaccinated moms, who convey maternal influenza antibodies via the placenta and through breast milk.
The new research, posted online, is slated to be published in the February 2011 issue of the Archives of Pediatrics & Adolescent Medicine. O’Brien and her colleagues zeroed in on Navajo and White Mountain Apache Indian reservations, where children typically contract more severe respiratory infections than the general population.
They studied 1,169 women who delivered babies during one of three influenza seasons and took blood samples from 1,160 mother-infant pairs. After crunching the numbers, they found that infants whose mothers were vaccinated had a 41% lower risk of a confirmed flu infection and a 39% reduced risk of hospitalization from flu-like illness. Blood analyses revealed that babies whose moms had gotten a flu shot had higher levels of flu antibodies at birth — and at 2 to 3 months — than babies of unvaccinated mothers. (More on Time.com: Want Good Health? There Are 10 Apps for That)
Pregnant women, experts say, should routinely opt for a flu shot. In September, a coalition of public-health groups including the March of Dimes, the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists called for pregnant women to be vaccinated as a matter of course. “Based on expert medical opinion, we urge all pregnant women, and women who expect to become pregnant, to get their influenza immunization because the flu poses a serious risk of illness and death during pregnancy,” says Jennifer Howse, president of the March of Dimes, in a news release.
Other studies, such as one from Emory University in Atlanta, have found that vaccinated women were 72% less likely to have a premature baby than those who did not receive the vaccine during a rampant flu season. And last year’s H1N1 pandemic highlighted the vulnerability of pregnant women to influenza. The H1N1 flu strain disproportionately infected expectant mothers, proving fatal in some cases. Although only 1% of the U.S. population is pregnant at any given time, pregnant women accounted for about 6% of confirmed H1N1 2009 influenza deaths. Yet more than a few pregnant women were skeptical of the brand-new vaccine and chose not to get immunized.
“Maternal influenza vaccination targets two high-risk groups with one vaccine dose — we can’t afford not to act,” wrote Justin Ortiz and Kathleen Neuzil, doctors at the University of Washington, in an editorial that accompanied O’Brien’s research.
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