Robert F. Kennedy Jr., the nation’s top health official, has an unorthodox idea for tackling the bird flu bedeviling U.S. poultry farms. Let the virus rip.

Instead of culling birds when the infection is discovered, farmers “should consider maybe the possibility of letting it run through the flock so that we can identify the birds, and preserve the birds, that are immune to it,” Mr. Kennedy said recently on Fox News.