UK scientists want to infect volunteers with Covid-19 in race to find vaccine

Trials could be speeded up by using risky strategy of deliberately introducing the virus

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Scientists have warned there could be major delays in producing a Covid-19 vaccine if current UK infection rates remain low and lengthy waiting times are needed to show if candidate products are working. As a result, some researchers insist that ministers must now consider implementing radical alternative measures to speed up vaccine development.

In particular, they argue that Britain should consider deliberately infecting volunteers involved in vaccine-testing projects - in line with World Health Organization proposals to set up such human challenge trials. Earlier this month, the WHO issued a 19-page set of guidelines on how these trials might operate.