BRUSSELS: The European Union said Monday it was working to secure a big increase in Covid-19 vaccine supplies to improve its slow roll-out, as the United States denounced what it called a Russian disinformation campaign.

The urgency of the global vaccine push was underlined by Latin America hitting 700,000 pandemic deaths, and Italy alone announcing that its toll had topped 100,000.

Meanwhile, former EU member Britain reopened its schools as a tough lockdown and successful first-jabs programme brought daily infection numbers down 90 percent from two months ago.

Nearly a year after first describing Covid-19 as a pandemic, the World Health Organization complained on Monday that some authorities failed to listen to its earlier urgent warnings.

"One of the things we still need to understand is why some countries acted on those warnings, while others were slower to react," WHO chief Tedros Adhanom Ghebreyesus told a press conference as the global death toll rose to at least 2.59 million.

In Washington, the United States attacked what it called an ongoing Russian disinformation campaign against US-made Covid-19 vaccines.

The Global Engagement Center, a US government agency that monitors foreign propaganda, said that Russian intelligence was behind four online platforms involved.

"It is very clear that Russia is up to its old tricks, and in doing so is potentially putting people at risk by spreading disinformation about vaccines that we know to be saving lives every day," a State Department spokesman said.

Signs of economic revival in the US -- where vaccinated people can now mingle unmasked per the latest medical recommendation -- point to the world's wealthier countries aiming for a mid-year bounceback from the pandemic.