A top official from the World Health Organization says Europe has surpassed 1 million deaths from the coronavirus disease 2019 (Covid-19) and the situation remains “serious,” with about 1.6 million new cases reported each week in the region.

The comments by Dr. Hans Kluge on Thursday aimed to emphasize that Europe must keep up its guard with social distancing and speed up vaccinations as virus variants drive new infections to record levels in some nations.

Overall, a tally by Johns Hopkins University shows nearly 3 million deaths have been linked to Covid-19 worldwide – with the Americas hardest hit, followed by Europe. The United States, Brazil and Mexico have reported the highest number of deaths, collectively at more than 1.1 million.

Speaking to reporters during a visit to Greece, Kluge did point to “early signs that transmission may be slowing across several countries” in WHO’s 53-country European region, which stretches into Central Asia —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 percent — the lowest level in the pandemic.

Britain in particular has seen new infections and Covid-19 deaths drop dramatically since January, due to a successful vaccination program and a prolonged national lockdown that is only being reversed in stages.

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

“Let there be no doubt about it, the AstraZeneca vaccine is effective in reducing Covid-19 hospitalization and preventing deaths,” he said, adding that WHO recommends its use for all eligible adults.