The World Health Organization has warned that, despite firm hopes for a vaccine, there might never be a "silver bullet" for COVID-19, and the road ahead back to normality would take long.
WHO director-general Tedros Adhanom Ghebreyesus and WHO emergencies head Mike Ryan have strongly encouraged all nations to rigorously enforce health measures such as mask-wearing, social distancing, handwashing, and testing.
"The message to people and governments is clear: 'Do it all,'" Dr. Tedros told a virtual news briefing from the UN body's headquarters in Geneva.
He said face masks should become a symbol of solidarity around the world.
"Several vaccines are now in phase three clinical trials, and we all hope to have some effective vaccines that can help prevent people from infection," he said.
"However, there's no silver bullet at the moment — and there might never be."
The WHO head said that, while the coronavirus was the biggest global health emergency since the early 20th century, the international hunt for a vaccine was historic.
"There are many vaccines under trial, a couple in the final stage of clinical trials — and there is hope," Dr. Tedros said.
"It does not mean that we will have the vaccine, but the speed we reached the level we reached now is unprecedented.
"There are concerns that we may not have a vaccine that may work or its protection could be for just a few months, not more. But until we finish the clinical trials, we will not know."