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May 6, 2015

Study Finds Factors That May Influence Flu Vaccine Effectiveness

The long-held approach to predicting seasonal influenza vaccine effectiveness may need to be revisited, new research suggests. Currently, seasonal flu vaccines are designed to induce high levels of protective antibodies against hemagglutinin (HA), a protein found on the surface of the influenza virus that enables the virus to enter a human cell and initiate infection.

New research conducted by scientists at NIAID found that higher levels of antibody against a different flu surface protein—neuraminidase (NA)—were the better predictor of protection against flu infection and its unpleasant side effects. Neuraminidase, which is not currently the main target antigen in traditional flu vaccines, enables newly formed flu viruses to exit the host cell and cause further viral replication in the body.

The findings, from a clinical trial in which healthy volunteers were willingly exposed to naturally occurring 2009 H1N1 influenza type A virus, appeared online Apr. 19 in the open-access journal mBio.

“Each year, between 3,000 and 49,000 people in the United States die as the result of seasonal influenza and its complications,” said NIAID director Dr. Anthony Fauci. “Annual vaccination against seasonal flu continues to be the most effective way to protect against infection, and this new study provides some interesting clues about how we might improve the level of protection that flu vaccines provide.”

Greenness Around Homes Linked to Lower Mortality

Women live longer in areas with more green vegetation, says new NIEHS-funded research.
Women live longer in areas with more green vegetation, says new NIEHS-funded research.

Women live longer in areas with more green vegetation, according to new research funded by NIEHS. Women with the highest levels of vegetation, or greenness, near their homes had a 12 percent lower death rate compared to women with the lowest levels of vegetation near their homes. The results were published Apr. 14 in the journal Environmental Health Perspectives.

The researchers found the biggest differences in death rates from kidney disease, respiratory disease and cancer. The scientists also explored how an environment with trees, shrubs and plants might lower mortality rates. They showed that improved mental health and social engagement are the strongest factors, while increased physical activity and reduced air pollution also contribute.

“It is important to know that trees and plants provide health benefits in our communities, as well as beauty,” said NIEHS director Dr. Linda Birnbaum. “The finding of reduced mortality suggests that vegetation may be important to health in a broad range of ways.”

The study examined greenness around the homes of 108,630 women in the long-term Nurses’ Health Study. The scientists consistently found lower mortality rates in women as levels of trees and plants increased around their homes. This trend was seen for separate causes of death, as well as when all causes were combined.

New Role Identified for Scars at Site of Injured Spinal Cord

For decades, it was thought that scar-forming cells called astrocytes were responsible for blocking neuronal regrowth across the level of spinal cord injury, but recent findings challenge this idea. According to a new mouse study, astrocyte scars may actually be required for repair and regrowth following spinal cord injury. The research was funded by NINDS and published in Nature.

“At first, we were completely surprised when our early studies revealed that blocking scar formation after injury resulted in worse outcomes,” said Dr. Michael Sofroniew, professor of neurobiology at the University of California, Los Angeles, and senior author of the study. “Once we began looking specifically at regrowth, though, we became convinced that scars may actually be beneficial. Our results suggest that scars may be a bridge and not a barrier towards developing better treatments for paralyzing spinal cord injuries.”

Neurons communicate with one another by sending messages down long extensions called axons. When axons in the brain or spinal cord are severed, they do not grow back automatically. For example, damaged axons in the spinal cord can result in paralysis. When an injury occurs, astrocytes become activated and go to the injury site, along with cells from the immune system, and form a scar.

Scars have immediate benefits by decreasing inflammation at the injury site and preventing spread of tissue damage. However, long-term effects of the scars were thought to interfere with axon regrowth.

“This important research provides further evidence about the complexity of the brain and spinal cord’s injury response,” said NINDS program director Dr. Lyn Jakeman. “It shows that scar-forming astrocytes

Healthy Diet May Reduce High Blood Pressure Risk after Gestational Diabetes

Another study lauds a diet rich in fruits, vegetables and whole-grain foods.
Another study lauds a diet rich in fruits, vegetables and whole-grain foods.

Sticking to a healthy diet in the years after pregnancy may reduce the risk of high blood pressure among women who had pregnancy-related (gestational) diabetes, according to a study by researchers at NIH and other institutions. The study was published in Hypertension.

“Our study suggests that women who have had gestational diabetes may indeed benefit from a diet rich in fruits, vegetables and whole grains and low in red and processed meats,” said the study’s senior author, Dr. Cuilin Zhang, a senior investigator in the Epidemiology Branch, NICHD.

In fact, a healthy diet was associated with lower risk for high blood pressure even in obese women. Obesity is a risk factor for high blood pressure. But obese women in the study who adhered to a healthy diet had a lower risk of high blood pressure, when compared to obese women who did not.

Approximately 5 percent of pregnant women in the United States develop gestational diabetes, despite not having diabetes before becoming pregnant. The condition results in high blood sugar levels, which can increase the risk of early labor and a larger than average baby, which may result in problems during delivery. For most women with the condition, blood sugar levels return to normal after birth. However, later in life, women who had gestational diabetes are at higher risk for type 2 diabetes and high blood pressure.

The current study is the first to show that adopting a healthy diet—known to reduce high blood pressure risk among the general population—also reduces the risk among women with prior gestational diabetes.

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