An obituary in Friday's editions about Dr. Robert J. Byrne, 58, who died Wednesday after a heart attack, incorrectly described him as the acting director of the National Institute of Allergy and Infectious Diseases. In fact, he was acting director of NIAID's extramural activities program. The director of NIAID is Dr. Richard M. Krause.

Dr. Robert J. Byrne, 58, acting director of the National Institute of Allergy and Infectious Diseases (NIAID), died Wednesday at Surburban Hospital in Bethesda after a heart attack.

Dr. Byrne, a veterinarian and microbiologist, had been an administrator and researcher with NIAID, which is part of the National Institutes of Health, since 1966. He was named NIAID's deputy director in 1977 and was its acting director at the time of his death.

During his years with the institute, he worked on projects involving the development of viral vaccines and on hepatitis studies. In 1975, he received the Department of Health, Education, and Welfare's Superior Service Award.

Dr. Byrne, who lived in Bethesda, was a member of the World Health Organization's Board for Comparative Virology. He was a past president of the Maryland State Veterinary Medical Association and the D.C. Veterinary Medical Association. He also was a member of the American Veterinary Medical Association, the International Association of Biological Standardization and other professional groups.

Dr. Byrne was a native of New Jersey. He attended Cornell University, where he did his undergraduate work and where he received his doctorate of veterinary medicine in 1944.

During World War II, he served in the Army's veterinary corps. He moved to the Washington area in 1949 to head the Maryland Board of Agriculture's Livestock Diagnostic Laboratory in Centreville. During the Korean conflict, he returned to active duty with the Army, retiring in 1953 with the rank of lieutenant colonel.

From 1954 to 1963, Dr. Byrne was associate professor of veterinary science at the University of Maryland. He received a master's degree in microbiology from George Washington University in 1958. He joined the National Institutes of Health in 1963 as chief of the laboratory aids branch, remaining in that position until he joined NIAID.

Survivors include his wife, Sara DeWitt Byrne of Bethesda, and three sons, Robert A., of Clinton, Iowa, James R., of Boston, and C. Thomas, of Bethesda.

The family suggests that expressions of sympathy be in the form of contributions to the Patient Emergency Fund, Clinical Center, National Institutes of Health, Bethesda, or to the World Wildlife Fund, Washington, D.C.