MARIETTA, Pa. — Malaria. Tuberculosis. Alzheimer's disease. AIDS. Pandemic flu. Genital herpes. Urinary tract infections. Grass allergies. Traveler's diarrhea. You name it, the pharmaceutical industry is working on a vaccine to prevent it.

Many could be on the market in five years or less.

Contrast that with five years ago, when so many companies had abandoned the vaccine business that half the U.S. supply of flu shots was lost because of contamination at one of the two manufacturers left.

Vaccines are no longer a sleepy, low-profit niche in a booming drug industry. Today, they're starting to give ailing pharmaceutical makers a shot in the arm.

The lure of big profits, advances in technology and growing government support has been drawing in new companies, from nascent biotechs to Johnson & Johnson. That means recent remarkable strides in overcoming dreaded diseases and annoying afflictions likely will continue.

"Even if a small portion of everything that's going on now is successful in the next 10 years, you put that together with the last 10 years (and) it's going to be characterized as a golden era," says Emilio Emini, Pfizer Inc.'s head of vaccine research.

Vaccines now are viewed as a crucial path to growth, as drugmakers look for ways to bolster slowing prescription medicine sales amid intensifying generic competition and government pressure to cut down prices under the federal health overhaul.

Unlike medicines that treat diseases, vaccines help prevent infections by revving up the body's natural immune defenses against invaders. They are made from viruses, bacteria or parts of them that have been killed or weakened so they generally can't cause an infection.