Human challenge trials are regarded by some as a faster way to develop vaccines – but they come with big risks.
Challenge trials have been used for hundreds of years but a lot of people question how ethical is to deliberately expose people to an infectious disease.
More than 140 different organisations around the world are currently trying to discover a vaccine for Covid-19.
But could challenge trials be used to speed up the process?
BBC Health Correspondent .css-yidnqd-InlineLink:link{color:#3F3F42;}.css-yidnqd-InlineLink:visited{color:#696969;}.css-yidnqd-InlineLink:link,.css-yidnqd-InlineLink:visited{font-weight:bolder;border-bottom:1px solid #BABABA;-webkit-text-decoration:none;text-decoration:none;}.css-yidnqd-InlineLink:link:hover,.css-yidnqd-InlineLink:visited:hover,.css-yidnqd-InlineLink:link:focus,.css-yidnqd-InlineLink:visited:focus{border-bottom-color:currentcolor;border-bottom-width:2px;color:#B80000;}@supports (text-underline-offset:0.25em){.css-yidnqd-InlineLink:link,.css-yidnqd-InlineLink:visited{border-bottom:none;-webkit-text-decoration:underline #BABABA;text-decoration:underline #BABABA;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-skip-ink:none;text-decoration-skip-ink:none;text-underline-offset:0.25em;}.css-yidnqd-InlineLink:link:hover,.css-yidnqd-InlineLink:visited:hover,.css-yidnqd-InlineLink:link:focus,.css-yidnqd-InlineLink:visited:focus{-webkit-text-decoration-color:currentcolor;text-decoration-color:currentcolor;-webkit-text-decoration-thickness:2px;text-decoration-thickness:2px;color:#B80000;}}Laura Foster explains how they work.
.css-po6dm6-ItalicText{font-style:italic;}Video by Terry Saunders, Megan Fisher and Laura Foster.
Source: BBC | BBC News & Gossip
