GENEVA — The World Health Organization does not expect widespread vaccinations against COVID-19 until the middle of next year, a spokeswoman said on Friday, stressing the importance of rigorous checks on their effectiveness and safety.

None of the candidate vaccines in advanced clinical trials so far has demonstrated a "clear signal" of efficacy at the level of at least 50 percent sought by the WHO, spokeswoman Margaret Harris said as quoted by Reuters.

"We are really not expecting to see widespread vaccination until the middle of next year," Harris told a UN briefing in Geneva.

"This phase 3 must take longer because we need to see how truly protective the vaccine is and we also need to see how safe it is," she added. This referred to the phase-in vaccine research where large clinical trials among people are conducted. Harris did not refer to any specific vaccine candidate.

All data from trials must be shared and compared, Harris said. "A lot of people have been vaccinated and what we don’t know is whether the vaccine works...at this stage, we do not have the clear signal of whether or not it has the level of worthwhile efficacy and safety...," she added. — WAM