World Health Organization's head of emergency services on Wednesday hailed Britain's approval of the Pfizer/BioNTech vaccine.
However, Dr. Mike Ryan said more vaccines are needed and until then measures such as wearing masks in public must be followed.
Ryan spoke with WHO epidemiologist Dr. Maria Van Kerkhove at a public forum about the COVID-19 hosted online.
They cited "hope" from vaccine developments but stressed the need for other safety measures.
"We shouldn't stop; we need more than 3-4 vaccines. We need to increase production; we need to pull the price down. We need a one-dose vaccine," said Ryan commenting on UK's vaccine developments.
UK became the first country to allow use of the Pfizer/BioNtech coronavirus vaccine on the public after clinical approval from the country's regulatory authority.
The vaccine, which provides 95% protection against COVID-19, will be rolled out as early as next week, a government statement said.