New vaccines against currently circulating influenza variants are required every year due to the diversity of<unk>  viruses and variable efficacy of vaccines to prevent them. A<unk>  vaccine would eliminate the need to create a vaccine for each year's variants. The efficacy of a vaccine refers to the protection against a broad variety of influenza strains. Events such as antigenic shift have created pandemic strains such as the H1N1 outbreak in 2009. The research required every year to isolate a potential popular viral strain and create a vaccine to defend against it is a six-month-long process; during that time the virus can mutate, making the vaccines less effective. High-risk populations, including the elderly and those with chronic disease, often acquire only limited immunity towards the<unk>  from vaccines. The vaccines have been found to be 30% to 70% effective in preventing hospitalization from the<unk>  or pneumonia. On average influenza vaccine efficacy is 60% among the general population that receive yearly vaccinations. A<unk>  vaccine could be manufactured in quantity and eliminate availability and supply issues of current vaccines. There is conflicting evidence on whether it would cut costs.
Universal flu vaccine
Rabies vaccine
Hantavirus vaccine
Dengue vaccine
Measles vaccine
Yellow fever vaccine
Ebola vaccine
Malaria vaccine