Once a vaccine is granted emergency approval, there is pressure to offer immunization to trial participants who received placebo. But if too many people cross over to vaccine group, companies might not have enough data to establish long-term outcomes,
nature.com/articles/d4158… https://t.co/UmW33iCr3l
RT @archaeologyart: Fragment of a Seljuk box with a combination lock, cast and hammered brass, inlaid with silver and copper.
January 18, 2021
RT @archaeologyart: Fragment of a Seljuk box with a combination lock, cast and hammered brass, inlaid with silver and copper. from Iran, Is…