April 15, 1986

An obituary of the poet John Ciardi on April 2 misidentified a school where he had been an English instructor. It was the University of Kansas City, not Kansas State University.

IF doctors develop an AIDS vaccine, will anyone want to be immunized? In the rush to develop a vaccine against acquired immune deficiency syndrome, a number of serious questions like this are not being adequately addressed, health care experts say. Questions are being raised now because some researchers are reporting glimmers of success in the early stages of developing a vaccine. But as is true with most scientific successes, with each step forward, the future steps and complications become more troubling, and the need for public discussion becomes more urgent. All the questions point to the extraordinary difficulty of developing a safe vaccine and to whether, even if one is developed, it will actually prove useful in halting the spread of the fatal disease. The AIDS virus has already widely infected those most at risk - male homosexuals and intravenous drug users - who, presumably, will not be helped by any vaccine.

An article on Saturday about job cutbacks at television stations owned by Capital Cities/ABC misidentified the ABC station in Chicago. It is WLS-TV, not WGN.

Salvage crews off the Florida coast have recovered a burned-out section of the booster rocket joint whose rupture is thought to have led to the destruction of the space shuttle Challenger, the Navy said yesterday. The discovery provides the first tangible evidence that a failure of the joint, whose questionable design had worried rocket engineers for nearly a year before the Jan. 28 explosion, caused the disaster, which took the lives of seven astronauts. After discovery of the crew cabin, which was hauled ashore last month, the search for the booster joint was the top priority for the flotilla of surface ships and submarines still combing the ocean floor off Cape Canaveral. Key 4,000-Pound Segment The wreckage, a 4,000-pound section of the aft-center segment of the rocket, was recovered early Sunday morning by the salvage vessel Stena Workhorse and an unmanned submersible working in 560 feet of water. Along one edge, where a tang fits into a groove on an adjacent rocket segment, a 2-foot-wide hole is evident, burned through the hardened steel of the rocket casing.

The United States conducted a series of air strikes on Monday night against what the White House called ''terrorist centers'' and military bases in Libya. President Reagan, in a nationally broadcast speech, said the American forces had ''succeeded'' in their mission of retaliating against Libya for what he termed the ''reign of terror'' waged by Col. Muammar el-Qaddafi, the Libyan leader, against the United States. Defense Secretary Caspar W. Weinberger said later that one United States plane, an F-111 with a crew of two, ''is not accounted for at this time.'' But he declined to say if the plane had been shot down. Libya Says 3 Jets Downed The Libyan radio, monitored in London, said that three United States aircraft had been shot down and that Libyans had killed their pilots and crew.