Monday, October 24, 2011

IDSA: Flu Vaccines In Pregnancy




Photo Credit – CDC

# 5920



Last week, in UK: Pregnancy And Swine Flu, we saw a study conducted at Oxford University by the National Perinatal Epidemiology unit that found a strong link between infection with the 2009 `swine’ flu and an increased number of stillbirths.


Fetal deaths among women infected with the H1N1 virus were 5 times higher than normal.


Very early into the 2009 H1N1 outbreak – even before the declaration of a pandemic by the World Health Organization – it became apparent that pregnant women were making up a disproportionate number of ICU admissions for influenza, and deaths.


Which is a pattern we’ve seen in pandemic outbreaks in the past (see Pregnancy & Flu: A Bad Combination).


While the CDC and other public health entities continue to stress the importance of seasonal flu vaccination for pregnant women, there remains some reluctance among pregnant women to get the shot.


Last week, several studies were presented at the 49th Annual Meeting of the Infectious Diseases Society of America (IDSA) reaffirming the benefits and safety of maternal vaccination.


The CDC has synopsized these studies and included a link to the IDSA press release.


Pregnancy and Influenza Vaccine Safety

Research shows:

Influenza vaccination during pregnancy protects newborns from getting influenza.

Pregnant women who get influenza vaccine pass their immunity to their babies in the form of flu antibodies. This protection lasts for several months after birth. Influenza protection was seen in newborns up to four months old. Babies born to women who were not vaccinated during pregnancy showed no antibody protection.

Influenza vaccination does not cause miscarriage.

Research shows no association between flu vaccination during pregnancy and miscarriage. This largest study conducted during the first trimester showed pregnant women who got the flu vaccine were no more likely to miscarry than those who did not get the flu vaccine.

More pregnant women are getting vaccinated against influenza.

The number of pregnant women receiving influenza vaccine has increased dramatically in the last couple of years in large part due to a national effort to vaccinate against the 2009 H1N1 pandemic influenza during the 2009-10 influenza season. Prior to 2009, less than 15 percent of pregnant women got vaccinated. In the past two influenza seasons, over half of pregnant women were vaccinated.

For more information on these studies, read the IDSA press release.




Vaccines are drugs, and there is no such thing as a 100% safe and 100% effective drug. Even taking over-the-counter medicines entail some risks.


But the safety profile of flu vaccines is excellent, and serious side effects are exceedingly rare.


The real risk comes from the virus, not from the shot.

While studies like the ones above are unlikely to dissuade most anti-vaccination activists, hopefully they will provide some reassurance to women who are considering the vaccine, but are still on the fence.