The hunt for a coronavirus vaccine is showing promise but it is premature to say the end of the pandemic is nigh.
Several rich countries have signed a 'frenzy of deals' that could prevent many poor nations from getting access to immunisation until at least 2024.
Also, many drug firms are potentially refusing to waive patents and other intellectual property rights in order to secure exclusive rights to any cure.
Michael Safi, the Guardian's international correspondent, explains why 'vaccine nationalisation' could scupper global efforts to kill the virus and examines what is being done to tackle the issue
