Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lessons from flu seasons past

02.11.2009
Risk of serious flu-related sickness far outpaces risk of injectable vaccine in pregnant women

Pregnant women who catch the flu are at serious risk for flu-related complications, including death, and that risk far outweighs the risk of possible side effects from injectable vaccines containing killed virus, according to an extensive review of published research and data from previous flu seasons.

The review, a collaboration among scientists from the Johns Hopkins Children's Center, Emory University and Cincinnati Children's Hospital, and published online Oct. 22 in the American Journal of Obstetrics & Gynecology, found substantial and persistent evidence of high complication risk among pregnant women -- both healthy ones and those with underlying medical conditions -- infected with the flu virus, while confirming vaccine safety. The findings, researchers say, solidify existing CDC recommendations that make pregnant women the highest-priority group to receive both the H1N1 and seasonal flu vaccines.

"The lessons learned from flu outbreaks in the distant and not-too-distant past are clear and so are the messages," says lead investigator Pranita Tamma, M.D., an infectious disease specialist at the Johns Hopkins Children's Center. "If you are an expectant mother, get vaccinated. If you are a physician caring for pregnant women, urge your patients to get vaccinated."

Because even healthy pregnant women end up in the hospital with preventable flu complications -- some devastating and some fatal -- at a rate far higher than that of other adults, and because of the proven effectiveness and overall safety record of flu vaccines, all pregnant women should consider getting vaccinated to prevent complications in both the expectant mother and her offspring, researchers say.

"Healthcare providers will play a key role in women's decisions about whether or not to be vaccinated against H1N1," says study senior investigator Saad Omer, M.B.B.S., M.P.H. Ph.D., of Emory University. "There is substantial evidence that vaccination is not only safe for pregnant women but that it is critical for protecting women and their infants against serious complications from the flu. Physicians and other providers should talk about risks and benefits with their patients and help alleviate any unfounded fears."

Even though there are still no published data on the safety of the new H1N1 vaccine, experts believe it to be just as safe as the seasonal flu vaccine, Johns Hopkins' Tamma says, because "the H1N1 vaccine is manufactured in the same rigorous way as the seasonal flu vaccines and we expect it to have a very similar safety profile as the other flu vaccines."

In their extensive review of data from three past flu pandemics and 11 published research studies on vaccine safety outcomes over 44 years, the researchers found no increased risk of either maternal complications or bad fetal results from the inactivated (injection) flu vaccine.

Researchers point out that even though study after study has found no link between the vaccine stabilizer thimerosal and autism, thimerosal-free injectable versions of the flu vaccine are available for those who have lingering concerns.

In their review, researchers say four studies have found evidence that antibodies protective against the flu, developed by the mother after vaccination, cross the placenta and transfer some protection to the fetus that lasts up to six months after birth.

Because pregnancy causes a variety of changes in the body, most notably decreased lung capacity, along with increased cardiac output and oxygen consumption, it puts pregnant women at high risk for complications. In addition, parts of the mother's immune system are selectively suppressed, a process that offers essential protection to the fetus, but decreases the mother's ability to fight off infection.

Other findings in the review:

In the first four months of the H1N1 flu outbreak this spring, pregnant women were hospitalized at four times the rate of other healthy adults infected with the virus, according to the CDC.

Pregnant women made up 13 percent of all H1N1 deaths during that period, and most of the women who died were previously healthy.

Pregnant women do not get infected with the flu more often than other adults, but they develop more serious complications and more often. Pregnant women with underlying conditions such as asthma or diabetes are at even higher risk for complications.

During the 1918 Spanish flu pandemic, of the 1,350 flu-infected pregnant women who were studied, half developed pneumonia, and more than half of those who did so died, with most deaths occurring during the third trimester.

During the 1957 pandemic, nearly half of all women of childbearing age who died of the flu were pregnant.

Eleven clinical studies closely followed pregnant women and/or their fetuses after vaccination and found no evidence of harmful side effects in either the mother or the fetus.

The Vaccine Adverse Event Reporting System database, a national repository of self-reports of adverse vaccine effects, showed 26 reports of adverse effects between 2000 and 2003, a period during which 2 million pregnant women were vaccinated against the flu. Of the 26 reports, six had to do with wrongly administered vaccine without any negative consequences; nine reports described brief injection site tenderness; eight involved systemic symptoms, such as malaise and fever; and three were miscarriages. Investigators point out that these are self-reported events and do not establish any evidence of cause and effect either with respect to either miscarriage or side effects.

The research was funded partially by an NIH fellowship training grant to Pranita Tamma. Co-investigator Neal Halsey, M.D., of Johns Hopkins, receives grant support from NIH, CDC, Berna, Intercel, Merck and Novartis, none of which went toward this particular research.

Other investigators in the study include Kevin Ault, M.D., and Carlos Del Rio, M.D., of Emory University; and Mark Steinhoff, M.D., of Cincinnati Children's Hospital.

Ekaterina Pesheva | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>