A group of San Francisco researchers has successfully used a vaccine to prevent pneumonia and reported their discovery in an issue of the New England Journal of Medicine published yesterday.

Dr. Joseph E. Addiego Jr., acting chief of Hematology at the Children's Hospital Medical Center of Northern California, said yesterday that if the government allows the use of the vaccine for young children, an entire generation of the country could be immunized within five years.

The vaccine, made from the sugar coating of the bacteria, is particularly important because it will be useful against new strains of pneumonia recently found that are resistant to the usual antibiotic treatment.