People in the United Kingdom have been living under lockdown for the past three weeks, hoping their sacrifice would bring the country's latest coronavirus surge -- caused by the new, more contagious variant of the virus -- under control.

But despite the harsh restrictions, case numbers are not dropping as fast as experts have hoped. Deaths continue to rise and public health experts and government are starting to warn people that the country will be in this battle for the long run.

The new variant, known as B.1.1.7, has wreaked havoc in the UK, fueling a surge in cases towards the end of 2020 despite a national lockdown being in place. Data showing an uptick in cases in younger people suggests this was largely because schools had stayed open, enabling the variant to spread rapidly.The UK is a cautionary tale of what could happen elsewhere. American public health experts are warning about a possible new surge in Covid-19 cases caused by the new strain first seen in southeast England. The US Centers for Disease Control and Prevention has warned that the new strain could become the predominant variant seen in the United States by March.

According to Public Health England, the new strain first emerged in September. By late November, scientists started to raise concerns over the rising number of infections in Kent in the southeast. The region was an anomaly, because while cases were generally going down across the country due to national restrictions, they weren't dropping in Kent.

By December, the country's leading epidemiologists were warning the new variant was outpacing the restrictions. It had by then spread to London where it was responsible for two-thirds of new cases.

This forced the country into a much stricter lockdown from January 5 in which people were instructed to stay at home, households were banned from mixing -- indoors and outdoors -- and everything but essential stores closed, including most schools.

For many experts, the decision came too late. "It's amazing that we seem to be making the same mistakes over and over again -- with increasing loss of life," Dr. Julian Tang, clinical virologist at the University of Leicester, noted in comments to the UK's Science Media Centre.

But is the harsher strategy working? The evidence is mixed.

Deadliest period

England reported nearly 70,000 new infections on January 4, the day before the new lockdown was announced. In terms of new cases reported, the country's worst 10 days of the entire pandemic happened between December 29 and January 11, averaging over 55,000 new cases each day.

Deaths soon followed: of the 11 deadliest days of the pandemic, 10 came between January 9 and 18. The country reported more than 1,000 deaths each day, something that has only happened once before.A few days after the new restrictions came into effect, the number of new cases began to gradually decline -- and have continued to since.

The seven-day rolling average of new daily cases, a measure that smooths out anomalies such as lower testing at the weekends, dropped from the height of above 60,000 on January 1 to around 40,000 in recent days. However, it will likely take time for the impact to be felt in hospitals.

"We know there is a lag between reporting of new cases and any subsequent deaths," Michael Head, a senior research fellow in global health at the University of Southampton, told CNN in an email. "For example, a few percent of newly-diagnosed today may end up in hospital in around 7-14 days from now, and then approximately 1% of today's cases will die in around 21-28 days' time," he added.

The number of people who are hospitalized remains at a record high, with 38,000 people in hospitals.

But while the latest figures might offer a glimpse of hope, other studies, including one by researchers at Imperial College London paints a contrasting picture.

One study, called REACT-1, shows that coronavirus infections remained high in early January and stayed that way for the first 10 days of lockdown, which is the period covered by the study.

Unlike the official case numbers, which are based on the number of people getting tested and thus may not include those who are asymptomatic or have not yet developed symptoms, the REACT-1 study tracks current coronavirus infections in the community and this time tested more than 140,000 randomly selected people.

Steven Riley, the author of the study and a professor of infectious disease dynamics at Imperial College, told CNN in an email that the figures do not show the kind of substantial decline that would be expected if the lockdown is strong enough to reduce the reproduction number -- the value indicates how much the virus is spreading: a reproduction rate of above 1 means the epidemic is growing. On Friday, the government said the number was between 0.8 and 1, although it cautioned this varied across the country.

The study tested samples collected between January 6 and 15 and compared them to mobility data based on the GPS locations of individuals using the Facebook mobile phone app. The data shows a decrease in mobility at the end of December, followed by increase in early January when people returned to work, which the authors say may explain the higher number of people becoming infected in early January.

Riley said that while the study did not show a big drop in infections, it wouldn't be fair to say the lockdown is entirely failing. "Our main point is that we did not detect a sharp decline which is what we really need to see."

The authors further noted in the paper that, "Until prevalence in the community is reduced substantially, health services will remain under extreme pressure and the cumulative number of lives lost during this pandemic will continue to increase rapidly."

Reacting to the numbers, Prime Minister Boris Johnson said the figures show the more contagious strain was spreading "very fast indeed."

"I think it's too early to say when we'll be able to lift some of the restrictions," Johnson said.

On Friday, the government added another piece of bad news, saying there were some indications that the new strain of the virus could be more deadly.

"When we look at severity and mortality, data for patients who are in hospital with the virus suggest the outcomes for those with the original variant look the same as the new variant," said Patrick Vallance, the UK government's chief scientific adviser. "However, when looking at the data for people who have tested positive, there is an indication that the rate for the new variant is higher," he added.

Vallance said the early data suggests that while roughly 10 of 1,000 infected men in their 60s would die of the old variant, this could rise to roughly 13 or 14 with the new strain.

The government has also found itself under pressure to compensate people who need to self-isolate. A government-backed study published in September found that only 18% of people adhered to the self-isolation rules and suggested financial compensation might bring that number up.

Full impact will take a while

While the numbers are debated and keep changing, health experts and politicians are asking the public for patience.

The full impact of the lockdown won't be felt for a while as it will take a long time -- and a lot more staying at home -- to get the latest surge fully under control, they believ

According to estimates by Head's team, the number of people who succumb to the disease is likely to remain high and only start falling next month. And while hospital admissions are decreasing, the number of patients who are in hospital remains at record levels. Until the number of people discharged is higher than those admitted, the hospitals will remain at risk of running out of beds.

"The daily trend is showing the lockdown having an effect on those new daily cases," Head said. "However, it is important to remember that impact on hospitalizations will only really be visible from trends starting around the last week of January, and deaths should be falling across February."

For now, this all means strict restrictions will stay in place for some time.

Top government officials have repeatedly said it is far too early to speculate about easing lockdown measures which are now scheduled to be in place until March, and possibly into the summer.

"It may well mean, for example, that any lockdown may have to be in place for longer than would have been the case with the old variant," Head said.