Coronavirus: What's happening in Canada and around the world Tuesday

The latest:

Many scientists are pressing the British government to reimpose social restrictions and speed up booster vaccinations as coronavirus infection rates, already Europe's highest, rise still further.

The U.K. recorded 43,738 new COVID-19 cases on Tuesday, slightly down from the 49,156 reported Monday, which was the largest number since mid-July. New infections have averaged more than 44,000 a day over the past week, a 16 per cent increase on the week before.

In July, Prime Minister Boris Johnson's government lifted all the legal restrictions that had been imposed more than a year earlier to slow the spread of the virus, including face coverings indoors and social distancing rules. Nightclubs and other crowded venues were allowed to open at full capacity, and people were no longer advised to work from home if they could.

Some modellers feared a big spike in cases after the opening-up. That didn't occur, but infections remained high, and recently have begun to increase — especially among children, who largely remain unvaccinated.

Also rising are hospitalizations and deaths, which have averaged 130 a day over the past week, with 223 reported Tuesday alone. This is far lower than when cases were last this high, before much of the population was vaccinated, but still too high, critics of the government say.

Some say Britons have been too quick to return to pre-pandemic behaviour. Masks and social distancing have all but vanished in most settings in England, including schools, though Scotland and other parts of the U.K. remain a bit more strict. Even in shops, where masks are recommended, and on the London transit network, where they are mandatory, adherence is patchy.

A plan to require proof of vaccination to attend nightclubs, concerts and other mass events in England was dropped by the Conservative government amid opposition from lawmakers, though Scotland introduced a vaccine pass program this month.

Some scientists say a bigger factor is waning immunity. Britain's vaccination program got off to a quick start, with shots given to the elderly and vulnerable starting last December, and so far almost 80 per cent of eligible people have received two doses. The early start means millions of people have been vaccinated for more than six months, and studies have suggested vaccines' protection gradually wanes over time.

Millions of people in Britain are being offered booster shots, but critics say the program is moving too slowly, at about 180,000 doses a day. More than half of the people eligible for a booster dose haven't yet received one.

The U.K. also waited longer than the U.S. and many European countries to vaccinate children ages 12-15, and only about 15 per cent in that age group in England have had a shot since they became eligible last month.

"It's critical we accelerate the booster program," said epidemiologist Neil Ferguson, a member of the government's Scientific Advisory Group for Emergencies.

Ferguson said one factor influencing the U.K.'s high case numbers was that it has relied heavily on the AstraZeneca vaccine, "and, while that protects very well against very severe outcomes of COVID, it protects slightly less well than Pfizer against infection and transmission, particularly in the face of the delta variant."

He also noted that "most Western European countries have kept in place more control measures, vaccine mandates, mask-wearing mandates, and tend to have lower case numbers and certainly not case numbers which are going up as fast as we've got."