A version of this article appeared in the print edition of The Straits Times on November 28, 2020, with the headline 'Covid-19 vaccines: Safety is top priority, but what is safety?'. Print Edition | Subscribe
We have been experiencing some problems with subscriber log-ins and apologise for the inconvenience caused. Until we resolve the issues, subscribers need not log in to access ST Digital articles. But a log-in is still required for our PDFs.