There’s diplomacy, there’s mask diplomacy and then there’s vaccine diplomacy.

China is determined to increase its influence at multilateral - and often regulatory - bodies like the United Nations and the World Health Organization.

This pledge to support Covax is fresh evidence of that commitment.

The scheme is aimed at distributing two million doses of a vaccine across the world, particularly to developing nations, by the end of next year.

The move is also though an element of what is certain to be "vaccine diplomacy", as China seeks to repair its image across a world dealing with a pandemic which originated in its borders.

We don’t know the specifics of the financial commitment to Covas - but it's a commitment that the US has not made.

President Donald Trump has labelled the organisation behind it, the WHO, "corrupt".

Stepping in where the US, and Russia, have so far refused to go demonstrates China’s wish to ensure what it called "equitable" distribution of a vaccine.

But there are plenty of questions that remain: will China, or indeed others, act unilaterally to give a vaccine to favored nations?

Will it reveal more about the vaccines it says it's given to thousands of key workers who are not part of the official human trials?