Dr. R. Palmer Beasley, an epidemiologist who discovered that hepatitis B is easily transferred from mothers to infants during childbirth, confirmed the role of the virus in causing liver cancer and saved millions of lives by helping to persuade world health officials to include a vaccine for the virus in its global recommendations for immunizations, died on Saturday at his home in Houston. He was 76.

The cause was pancreatic cancer, said his wife, Dr. Lu-Yu Hwang.

Dr. Beasley became particularly interested in hepatitis B in the mid-1960s, after it was isolated in the blood serum of an aboriginal Australian by Dr. Baruch S. Blumberg, an American who later helped develop the vaccine and shared the Nobel Prize for his research in infectious diseases.

Hepatitis B and liver cancer were far more common in developing countries than in the United States, and Dr. Blumberg and others struggled to understand why. It was Dr. Beasley and his colleagues who discovered that in developing countries hepatitis B, a blood-borne virus, was commonly passed from mother to infant during childbirth.

At the time, Dr. Beasley was on the faculty of the University of Washington but was working in Taiwan at a special American medical research unit in Taipei. He and his colleagues began what became a decades-long study of 22,000 Taiwanese civil servants, which helped determine that immunizing infants at birth was the best way to prevent them from contracting hepatitis B as well as cirrhosis and liver cancer. Before the vaccine was developed, infants had a much higher rate of contracting a chronic form of the virus, which often showed no symptoms until it developed into cirrhosis or liver cancer decades later.