A 66-year-old man from New Hampshire became the fourth person to receive a pig’s kidney.

The stop-work order on U.S.A.I.D.-funded research has left thousands of people with experimental drugs and devices in their bodies, with no access to monitoring or care.

Lifesaving treatment and prevention programs for tuberculosis, malaria, H.I.V. and other diseases cannot access funds to continue work.

The drug, Journavx by Vertex Pharmaceuticals, blocks pain signals to the brain, making it nonaddictive.

While some agree with Robert F. Kennedy Jr. that the agency needs reform, their ideas for fixing it are very different from his.