The Pfizer Covid-19 vaccine helps prevent severe disease among those infected with the Delta variant, according to research involving 1.2 million medical insurance plan members in South Africa.

Two weeks after the first dose, the Pfizer vaccine is 73% effective in protecting against hospital admission, according to a study. Waiting the same period after the second shot raises that to 92%. For those that have had Covid-19 and followed the two-dose regimen, there is a 98% drop in the risk of hospital admission.

Russia on Friday reported nearly 1,200 deaths from Covid-19 over the past day, just short of its record in a persistent wave of coronavirus infections that closed most businesses in the country this week.

The national coronavirus task force said 1,192 people died in the past 24 hours and 40,735 new infection cases were tallied.

Officials blame the low vaccination rate as a major factor in the sharp rise in cases that began in mid-September.