Although scientists debate the ethics of deliberately infecting volunteers with SARS-CoV-2, plenty of consenting participants have been exposed to all sorts of pathogens in prior trials.

The monoclonal antibody, known as mAb114, is likely to be used in the current Ebola outbreak in DRC.

Some vaccine developers are taking steps to include them, in line with bioethicists' urging, but it will likely take years before any expectant mothers are enrolled.