Russian President Vladimir Putin ordered people to stay off work for at least a week while Latvia has introduced a monthlong Covid-19 lockdown as deaths climb, driving renewed fears of another wave of infections as winter sets in.

Mr. Putin signed a decree Wednesday approving a period of nonworking days, as the government calls them, beginning Oct. 30 and stretching to Nov. 7 to encourage people to stay home and slow the spread of the virus. Regional governments where infection rates are especially virulent can speed up or prolong the measures, with employers continuing to pay their staffs as they stay home.

Latvia, which until recently had outperformed other European countries in containing the virus, on Monday announced a slate of strict measures, including a nationwide 8 p.m. to 5 a.m. curfew and closures of schools and nonessential retail after the seven-day average of deaths in the tiny Baltic state more than doubled last week.

Mr. Putin’s order came as some European countries, notably the U.K., have recorded a rise in coronavirus cases, triggering concern over a fourth wave of the virus taking hold as winter approaches.

“We know that this problem, unfortunately, is growing, and it is impossible not to pay attention to it,” Mr. Putin told a televised meeting of his government. “Our main task is to protect the life and health of citizens as much as possible, to minimize the negative consequences of a dangerous infection. And for this, it is now, first of all, important to bring down the pace of its spread.”

Russia has faced an uphill battle in curbing the spread of the virus, in large part because of the laid-back approach of many Russians to mitigation measures such as social distancing and wearing face coverings in public.

There is also widespread skepticism over vaccinations. Russians can choose from four homegrown shots, including Sputnik V, which made its debut in August 2020 as the world’s first registered Covid-19 vaccine. But only 31% of Russians are fully vaccinated, according to figures collected by Our World in Data, compared with 56% in the U.S., 67% in the U.K. and 86% in Portugal. Just over half of Latvia’s population has been fully vaccinated.

Experts say high vaccine hesitancy in Russia stems from a deep mistrust of the state—which sponsored the development of the Russian vaccines—and its medical system, as well as assurances by officials earlier this year that Russia had defeated the virus.