Pfizer says placebo patients will eventually get its Covid-19 vaccine. The question of when is complicated

Pfizer says placebo patients will eventually get its Covid-19 vaccine. The question of when is complicated

Source: 
Stat
snippet: 

Should patients who volunteer to be in Covid-19 vaccine studies, but who are assigned to get placebo, be offered the vaccine? As companies and regulators raced to start clinical trials in the summer, that question was left open.