Navigation Links
Study: Obesity limits effectiveness of flu vaccines
Date:10/25/2011

People carrying extra pounds may need extra protection from influenza.

New research from the University of North Carolina at Chapel Hill shows that obesity may make annual flu shots less effective.

The findings, published online Oct. 25, 2011, in he International Journal of Obesity, provide evidence explaining a phenomenon that was noticed for the first time during the 2009 H1N1 flu outbreak: that obesity is associated with an impaired immune response to the influenza vaccination in humans.

"These results suggest that overweight and obese people would be more likely than healthy weight people to experience flu illness following exposure to the flu virus," said Melinda Beck, Ph.D., professor and associate chair of nutrition at the UNC Gillings School of Global Public Health and senior author of the study.

"Previous studies have indicated the possibility that obesity might impair the human body's ability to fight flu viruses. These new findings seem to give us a reason why obese people were more susceptible to influenza illness during the H1N1 pandemic compared to healthy weight people."

The study reports for the first time that influenza vaccine antibody levels decline significantly in obese people compared to healthy weight individuals. What's more, responses of CD8+ T cells (a type of white blood cell that plays a key role in the body's immune system) are defective in heavier people.

Researchers studied people at a UNC clinic who had been vaccinated in late 2009 with inactivated trivalent influenza vaccine, the common flu vaccine for that fall and winter season. Although obese, overweight and healthy weight individuals all developed antibodies to flu viruses within the first month after vaccination, the antibody levels in the blood declined more rapidly in obese and overweight individuals over time.

About 50 percent of obese participants had a four-fold decrease in antibody levels at 11 months compared to one month post vaccination. However, less than 25 percent of healthy weight participants had a four-fold decrease in antibody levels.

Also, when study participants' blood samples were tested in the lab and exposed to a flu virus 11 months after vaccination, about 75 percent of healthy weight people's CD8+ T cells still expressed interferon-γ, an infection-fighting protein. However, only about 25 percent of obese patients' cells responded by producing the protein.

When vaccination fails to prevent flu infection, people must rely in part on their CD8+ T cells to limit the spread and severity of infection, said Patricia Sheridan, Ph.D., research assistant professor of nutrition and an author on the paper.

"If antibody titers are not maintained over time in the obese individuals and memory CD+ T cell function is impaired, they may be greater risk of becoming ill from influenza," Sheridan said.

Heather Paich, a doctoral student in Beck's lab, added: "The findings also suggest overweight and obese people are more likely to become sicker and have more complications. That's because influenza-specific CD8+ T cells do not protect against infection, but instead act to limit the disease's progression and severity of disease."

In 2005, Beck and her colleagues reported that obesity in mice impaired the animals' ability to fight influenza infections and increased the percent dying from influenza, compared to lean mice with the same infections. In 2010, her team showed that obesity seemed to limit the mice's ability to develop immunity to influenza, suggesting vaccines may not be as effective in obese and overweight as in healthy weight humans. Also, the fatality rate was higher in obese mice none of the lean mice died, but 25 percent of the obese mice died.

"This latest study shows that obese people may have a similar impaired response to influenza vaccines as our mouse models did to influenza virus," Beck said. "We need to continue to study the effect of obesity on the ability to fight virus infections. Influenza is a serious public health threat, killing up to half a million people a year worldwide. As rates of obesity continue to rise, the number of deaths from the flu could rise too. We need to better understand this problem and to look for solutions."


'/>"/>

Contact: Ramona Dubose
ramona_dubose@unc.edu
919-966-7467
University of North Carolina School of Medicine
Source:Eurekalert

Related medicine news :

1. Mayo Clinic study: PSA test valuable in predicting biopsy need, low-risk prostate cancer
2. Rochester study: Age a big factor in prostate cancer deaths
3. Virginia Commonwealth University study: We are what we experience
4. Mayo Clinic study: multiple surgeries and anesthesia exposure
5. Study: Overweight older women have less leg strength, power
6. Study: No link betweem menopause and increased risk of fatal heart
7. Study: 85 percent of homeless people have chronic health conditions
8. Study: Afghan patients a common source of drug-resistant bacteria
9. Study: Community organization can reduce, negate impact of alcohol outlets on neighborhood violence
10. Study: Graphic warning labels reduce demand for cigarettes
11. Study: Inexpensive method detects ALK rearrangement in lung cancer patients
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/28/2017)... FL (PRWEB) , ... May 28, 2017 , ... ... of America (PPOA), is proud to announce that Sheldon K. Cho, MD, has ... interventional pain management, a specialty that concentrates on minimally invasive techniques to treat ...
(Date:5/27/2017)... ... May 27, 2017 , ... In any business, follow up ... talent of your dental team at presenting treatment, there will always be some patients ... of time and money on best practices when it comes to presenting treatment. ...
(Date:5/26/2017)... (PRWEB) , ... May 26, 2017 , ... ... met this week to review more than eighty-nine grant submissions all vying ... emerging young scientists in the Parkinson’s field.     , The American Parkinson Disease Association ...
(Date:5/26/2017)... Clara, Calif. (PRWEB) , ... May 26, 2017 ... ... announces the integration of the CareFusion NOX-T3 portable sleep monitor with its Somnoware ... provides a consistent, browser-based interface for diagnostic device operations. With this platform, initializing ...
(Date:5/26/2017)... ... May 26, 2017 , ... On May 24, the ... narrowly passed the U.S. House on May 4, would result in 23 million Americans ... continued implementation of the 2010 Patient Protection and Affordable Care Act (ACA). , ...
Breaking Medicine News(10 mins):
(Date:5/9/2017)... , May 9, 2017 Zimmer Biomet Holdings, ... musculoskeletal healthcare, today announced it has earned a spot ... 2017" list. The Company was ranked among 500 U.S. ... Employers and Healthcare Equipment and Services. The ... on an anonymous, independent survey of over 30,000 employees ...
(Date:5/9/2017)... 2017  Semler Scientific, Inc. (OTCQB: SMLR), an ... improve the clinical effectiveness and efficiency of healthcare ... quarter ended March 31, 2017. ... to identify when preventive care options are appropriate, ... heart attacks or strokes occur," said Doug ...
(Date:5/6/2017)... --  Provista , a proven leader in the supply chain ... Jim Cunniff as the company,s new president and ... to Provista, including most recently serving as the president and ... . He assumed his new role with Provista on May ... Provista," says Jody Hatcher , president, Sourcing and Collaboration ...
Breaking Medicine Technology: