The director of the World Health Organisation has warned against “vaccine nationalism” and outlined the 20 per cent of the global population it believes should be vaccinated first against Covid-19.

WHO director-general Tedros Adhanom Ghebreyesus said yesterday that “no one is safe until everyone is safe” from the coronavirus that has irrevocably changed the world in 2020.

While there is a wish among leaders to protect their own people first, the response to this pandemic has to be collective,” he said.

“This is not charity, we have learned the hard way that the fastest way to end this pandemic and to reopen economies is to start by protecting the highest risk populations everywhere, rather than the entire populations of just some countries.

“No one is safe until everyone is safe.”

The WHO chief said he has written to each member state inviting them to join the COVAX Global Vaccines Facility which will guide how vaccines are shared.

He said countries should learn from initial stockpiling and shortages of PPE that left many people vulnerable to the virus and work together to return to life as we once knew it.

The comments come as Prime Minister Scott Morrison announced Australia had secured 25 million doses of the Oxford University vaccine, that the country would manufacture in partnership with AstraZeneca.

The Oxford vaccine – made from a modified chimpanzee cold virus – is regarded as one of the leading prospects in the global race and is already in phase three trials involving large scale testing in various countries.

There are more than 168 vaccines in development with eight in phase three trials, including the Oxford one, the US Moderna version as well as a German and Chinese variations. Just two have been approved for use so far, including a Chinese version and a Russian vaccine announced last week but met with scepticism.

The PM’s announcement will ensure a free dose for all Australians if the Oxford version proves successful. Other countries have made multiple bets on different vaccines in the hope one proves effective. The UK, for example, is backing six different versions in development and purchasing large quantities to develop a potential stockpile of 340 million doses.

How vaccines will be distributed in practice remains to be seen, however it’s generally assumed frontline healthcare workers and those with pre-existing conditions that make them vulnerable to the virus will be first in line.

On Tuesday, Tedros said the WHO wanted to see vaccine allocation rolled out in two phases with 20 per cent of the population in all countries – including healthcare workers and those with certain comorbidities to get it first.

“In phase 1, doses will be allocated proportionally to all participating countries simultaneously to reduce overall risk,” he said.

“In phase 2, consideration will be given to countries in relation to threat and vulnerability.”

He said “front line workers in health and social care settings” will be prioritised as they are “essential to treat and protect the population and come in close contact with high-mortality risk groups”.

“For most countries, a phase 1 allocation that builds up to 20 per cent of the population would cover most of the at-risk groups.

“If we don’t protect these highest risk people from the virus everywhere and at the same time, we can’t stabilise health systems and rebuild the global economy.

“This is what the first crucial phase of the vaccine allocation mechanism aims to do.”