After a year, the World Health Organization says there is reason for a “great hope.”

The pandemic “triggered the fastest and most wide-reaching response to a global health emergency in human history,” WHO Director General Tedros Adhanom Ghebreyesus said on Wednesday in a video statement marking the anniversary of the first reported cases and looking ahead to the new year. He cheered an “unparalleled mobilization of science.”

The rosy sentiment was in stark contrast to the organization’s comments earlier this week warning that covid-19 was “not necessarily the big one.”

Covid-19 ‘not necessarily the big one,’ WHO warns

In December, countries began to have a greenlight with the development of vaccines at a recorded speed. 

Britain became the first nation on Wednesday to approve the vaccine developed by Oxford and Astra-Zeneca, as it grapples with a new, more infectious variant of the virus.

“Vaccines offer great hope to turn the tide of the pandemic,” Tedros said. He urged the world to focus on equity in their distribution. “We must ensure that all people at risk everywhere, not just in countries who can afford vaccines, are immunized.”

Covax, the WHO-linked initiative aimed at equitable distribution of the vaccines, has secured 2 billion doses from vaccine candidates, but health experts warn that it could take until 2024 for some lower- and middle-income countries to see robust inoculation campaigns.

Thursday marks a year since the first reports of coronavirus infections emerged, scientists have theorized that the virus was spreading around the world as early as November 2019.

The Chinese government has largely blocked the drive to track down the virus’s origin. The Associated Press reported that scientists have been stonewalled in their efforts, with samples confiscated by the government, which is actively promoting unproven claims that the virus originated outside China.