Stig Børsen Hansen, a founding member who was one of two reviewers who presented the study to the Danish committee, resigned from the group in protest on Friday, citing major ethical issues with the study.

“You are now enrolling newborns in a lottery to test a hypothesis,” Hansen said. The children who are randomly selected not to receive the birth dose of the vaccine, those who “lost the lottery”, face in their earliest days the risk of contracting hepatitis B, which can cause irreversible lifelong damage. “They contract hepatitis B in the context of being part of a research project,” Hansen said, which made their infection happen, in effect, “by design”.