Ethiopian biologist Tedros Adhanom Ghebreyesus, who leads the World Health Organization, warned citizens to keep adhering to social distancing and mask-wearing rules in a bid to halt the spread of COVID-19.

The head of the UN’s World Health Organization warned on Thursday that people need to remain on the guard as the world awaits a coronavirus vaccine.

WHO chief Tedros Adhanom Ghebreyesus said social distancing and mask-wearing rules need to be adhered to in order to help bring about an end to the pandemic.

“We may be tired of COVID-19, but it is not tired of us. European countries are struggling but the virus has not changed significantly, nor the measures to stop it,” Tedros told the Paris Peace Forum.

“A vaccine is needed urgently, but we cannot wait for a vaccine and put all our eggs in one basket,” he added, repeating a call for any COVID-19 vaccine to be shared fairly with poorer countries as well.

The Paris Peace Forum is being held in the French capital on Thursday and Friday with the aim of improving access to testing and vaccines. Organizers said they expected both the private and public sectors to pledge hundreds of millions of dollars in total to help with that fight.

France is set to offer €100 million (roughly $118 million), Spain €50 million and the European Commission €100 million specifically towards the finding of vaccines. The fundraising is for the benefit of the so-called ACT-Accelerator, a WHO-led global initiative.

Leaders taking part include French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau, and IMF chief Kristalina Georgieva.

The conference comes just days after Germany’s BioNTech and American pharmaceutical giant Pfizer announced highly promising results for their vaccine candidate, raising hopes globally. The two companies said on Monday that the potential vaccine was 90% effective against COVID-19, based on the initial results of its trials.

Russia issued similar preliminary results soon after for its Sputnik V vaccine candidate, with many more potential vaccines in testing phases around the world.

The coronavirus has killed more than 1.2 million people worldwide, while measures to try to contain it have upended economies across the globe. A spike in infections has seen fresh lockdown measures adopted by several governments in recent weeks, particularly in Europe, in a bid to stop the spread of the virus and protect healthcare systems.