The vaccine against human papillomavirus (HPV), the sexually transmitted virus that causes cervical cancer, is very cost-effective when given to girls at age 12 but a government-funded now raises questions about the value of pushing for vaccinating women ages 13 to 21.

Two researchers at the Harvard School of Public Health who did the study took into account the benefit of an intervention such as a vaccine in terms of the person's health and also the cost of the intervention to determine the cost-effectiveness

The U.S. Food and Drug Administration on Tuesday approved new strains of influenza vaccines for the 2008-09 flu season. The federal agency has changed all three strains for this year's vaccine.

Flu vaccines are altered every year, however, usually, only one or two strains change. This year, all three strains have been changed. Two of the three strains recommended for the United States this year are now in use for the Southern Hemisphere's 2008 flu season, which is underway, the FDA said on its Website

With the onset of the flu season, the first protection for seniors, who are considered among the most vulnerable, is the flu vaccine. However, a new study says the vaccine is less beneficial and may not protect older people from pneumonia after they have the disease.

Researchers collected data on 1,173 people between 65 and 94 who had pneumonia. These individuals were compared with 2,346 people who did not get pneumonia. Both groups had similar rates of flu vaccination over three seasons of studies, the researchers say

Parents who care for mentally-challenged children are prone to develop weak immune systems due to stress, new research suggests. The study concluded that such parents should be offered a better support system.

Researchers at Birmingham University analyzed 60 parents who received the pneumococcal vaccine as part of the study. Half of them had children with developmental disabilities

A measles outbreak affecting 120 people in 15 states has alarmed health officials as it's the largest outbreak to happen in the last 10 years, according to the Centers for Disease Control and Prevention.

U.S. health authorities believe that the measles outbreak is related to travelers coming back to the United States from other countries