GENEVA -- A top official from the World Health Organization says Europe has surpassed 1 million deaths from COVID-19 and the situation remains "serious," with about 1.6 million new cases reported each week in the region.

Addressing recent concerns about vaccines, Dr. Hans Kluge also said the risk of people suffering blood clots is far higher for people with COVID-19 than people who receive AstraZeneca's coronavirus vaccine.

Speaking to reporters during a visit to Greece, Kluge did point to "early signs that transmission may be slowing across several countries" and cited "declining incidence" among the oldest people.

He said the proportion of COVID-19 deaths among people over 80, who have been prioritized for vaccines, had dropped to nearly 30% -- the lowest level in the pandemic.

"For now, the risk of suffering blood clots is much higher for someone with COVID-19 than for someone who has taken the AstraZeneca vaccine," he said.

"Let there be no doubt about it, the AstraZeneca vaccine is effective in reducing COVID-19 hospitalization and preventing deaths," he added, saying WHO recommends its use for all eligible adults.