Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
New High-Dose Flu Vaccine Better Protects Seniors
A new high-dose flu vaccine for seniors is more effective than the standard shot, according to a study by vaccine manufacturer Sanofi Pasteur.
People 65 and older generally have weaker immune systems and regular flu shots tend to be only 30 to 40 percent effective in them, according to experts. The study found that the new Fluzone High-Dose vaccine was 50 percent effective in seniors, the Associated Press reported.
In other age groups, the effectiveness of the regular flu vaccine can be 60 percent.
The Sanofi study of 32,000 seniors in the U.S. and Canada during the last two flu seasons found that the high-dose vaccine was 24 percent more effective than the regular vaccine at preventing flu.
"I wouldn't call it great," flu vaccine researcher Dr. Edward Belongia, of the Marshfield Clinic Research Foundation in Wisconsin, told the AP. He was not involved in the study.
But Belongia added that any improvement in protecting seniors from the flu is welcome.
A Sanofi executive was scheduled to present preliminary study findings on Thursday at a meeting of the Advisory Committee on Immunization Practices, which advises federal health officials, the AP reported.
Many Parents Concerned About Football Brain Injury Risk: Survey
About 1 in 3 American parents say the link between football-related concussions and long-term brain injury would make them less likely to allow their son to take the field, a new poll finds.
But 39 percent said that reports of such risk hasn't changed their level of concern about the game, according to CBS News.
Seventy percent of respondents believe the benefits of playing football outweigh the risks, while 24 percent say the risk of injury is too high, the HBO Real Sports/Marist survey found.
"It's a dilemma. It is a tough decision for a parent to make. But the good news about the study is that it creates real public awareness," Liz Giordano, of the Head Injury Association, told CBS News.
Ob/Gyns Change Pregnancy Length Definitions
New definitions of preterm and full term pregnancies have been released by the American College of Obstetricians and Gynecologists.
Until now, a baby was considered preterm if born before 37 weeks of pregnancy and full term if born anytime from 37 to 42 weeks, the Associated Press reported.
The new definitions are: early term, between 37 weeks and 38 weeks 6 days; full term, between 39 weeks and 40 weeks 6 days; late term, the 41st week; post term, after 42 weeks. On average, a pregnancy lasts 40 weeks.
The updated classifications were published Tuesday in the journal Obstetrics & Gynecology.
The new definition of a full term pregnancy is meant to reflect the fact that even at the end of the last trimester, a bit more time in the womb can benefit a baby's development and health.
"Weeks matter," Dr. Jeffrey Ecker of Massachusetts General Hospital, chair of the ACOG committee that came up with the more specific labels, told the AP. Since babies' outcomes can differ, "let's not call it all the same," he said.
In recent years, experts have emphasized that that elective deliveries -- inductions and cesarean sections scheduled without a medical reason -- shouldn't be performed before the 39th week of pregnancy. Studies show that infants born at 37 weeks have a higher risk of complications, such as difficulty breathing, than those born just two weeks later.
The new definitions were welcomed by the March of Dimes, which said they will eliminate "confusion about how long an uncomplicated, healthy pregnancy should last," the AP reported.