Watch live: The World Health Organization holds a press briefing on the coronavirus pandemic

The World Health Organization is holding a briefing Thursday on the coronavirus pandemic, which has infected more than 24.2 million people worldwide and killed at least 826,300, according to data compiled by Johns Hopkins University.

Last week, the agency said a vaccine will be a “vital tool” in the global fight against the virus, but it won’t end the pandemic on its own and there’s no guarantee scientists will find one. 

World leaders and the public must learn to manage the virus and make adjustments to their daily lives to bring the virus down to low levels, WHO Director-General Tedros Adhanom Ghebreyesus said Friday. “At the same time, we will not, we cannot go back to the way things were.”

Even though human trials for potential vaccines are progressing, scientists say key questions remain. While numerous research papers and studies have been produced on the virus, scientists still don’t fully understand how it affects the body or how well someone is protected from reinfection after recovering.

The WHO said Wednesday it is possible that people who recovered from the disease could be reinfected. 

Read CNBC’s live updates to see the latest news on the Covid -19 outbreak.