COVID's 'worst weeks' are yet to come: UK

The British government's chief medical adviser, Professor Chris Whitty, has confirmed that the next weeks of the pandemic will be the worst yet to hit that country - even as it rushes to ramp up its mass vaccination program.

COVID deaths have exceeded 81,000 in the UK, one of the worst tolls in the world, and in parts of London it's believed that one in 20 people are infected.

Seven mass vaccination centers have also now opened, and there's hope of reaching all those in the top four priority groups -- about 15 million people -- by the middle of February.

Prime Minister Boris Johnson:

"In the next few days as we get towards that target of the 15th of February, 15 million that we want to do, obviously the NHS is going to be ramping that up."

The strain on Britain's National Health Service cannot be understated.

During the peak of the first wave, last April, about 18,000 people were hospitalized with coronavirus and there were rampant fears that hospitals would be overwhelmed. Now that number is 30,000, according to the government.

In London the ambulance service is under so much pressure that firefighters have been drafted in to drive some vehicles, and police officers may soon follow.

But enforcement of social distancing and lockdown rules has been a constant question.

Headlines about illegal parties, protests, and general street enforcement come daily in the UK.

On Monday a lobby group representing Britain's retail sector called on police to better enforce the measures in stores, where shop workers can face violence and abuse from unruly customers.

The British government has also expressed particular concern about spread of the disease in supermarkets.