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 Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>