Just how bad has the second wave become compared with the first?
The UK is seeing record numbers of people testing positive for coronavirus, with more than 60,000 positive tests reported on three days this week.
But mass testing was not available during the first wave, and even now testing is aimed at those with symptoms so does not capture all cases. Similarly, population surveys such as that from the Office for National Statistics only began in late spring. However, the latest ONS data shows about one in 50 people in the community in England had coronavirus in the most recent week: an alarmingly high figure.
The situation in hospitals is perhaps easier to compare against the first wave, and the picture is bleak: both daily hospital admissions and the number of people in hospital with Covid have exceeded figures from the first wave, with more than 30,000 Covid patients now being treated in hospital compared with a peak of 21,684 in April.
NHS workers have reiterated that the situation is worse today, with a growing number of hospitals cancelling even urgent operations and fears there could be a shortfall of more than 5,000 beds by 19 January.
Daily reported deaths from Covid within 28 days of a positive test have not yet exceeded those of the first wave, in part because of the introduction of medications such as dexamethasone, although deaths also lag infections and hospitalisations. But the death toll is climbing steeply, with a total of more than 100,000 deaths likely to be reached by the end of the month.
Is this because of the new variant? Or did Christmas mixing play a role?
The UK variant is certainly a big factor: experts say it is between 50% and 70% more transmissible than older variants.
“Given that the old variants declined over Christmas in all regions while the new variants rose, I think the new variant explains most of the increases seen. But it is very hard to definitively unpick the causes of increases in case numbers,” Prof Neil Ferguson told the Guardian.
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The time lag between infection and hospitalisation means Christmas mixing might be starting to be seen in other data: Prof Christina Pagel, a member of Independent Sage, said regions that were allowed to mix over Christmas – the north-west, north-east, Midlands and south-west – have experienced quite steep increases in admissions over the last few days.
But, she said: “You can’t say for sure that it’s Christmas or the new strain, except of course that both together will compound the impact.”
Was this winter surge predicted and could we have avoided it with earlier or stricter lockdowns?
A winter surge was certainly anticipated, and many called for tighter measures to be taken sooner at various points since the summer, including scientists on the Scientific Advisory Group on Emergencies (Sage).
Whether a rise in cases could have been avoided even with a lockdown is another matter.
During the UK lockdown in the spring the R number fell to between 0.6 and 0.9 by the end of April, however research, led by scientists at Imperial College London, largely based on data relating to the second England lockdown, has revealed the new variant has an R number0.4-0.8 larger than older variants, making it doubtful similar measures would lower the R number to below 1.
One document from Sage dated to 22 December noted that: “It is not known whether measures with similar stringency and adherence as spring, with both primary and secondary schools closed, would be sufficient to bring R below 1 in the presence of the new variant.”
The latest data from the ONS survey does offer some hope, with models suggesting the rise in positivity rate for Covid is showing tentative signs of slowing in London and other regions that have been under tier 4 for restrictions for some weeks, however the ONS team urged caution.
“The proportion of people testing positive for Covid-19 has continued to rise across all regions in recent weeks,” they said. “Caution should be taken in overinterpreting any small movements in the latest trend.”
When are cases and deaths expected to peak and start to improve?
The number of people reported as testing positive fell on Thursday compared with earlier in the week. However, it is too soon to say that the peak in cases has been passed, not least as the high number of cases midweek could include some effect of delays over the festive period, while cases rose to more than 68,000 on Friday.
There are also concerns that the national lockdown could take longer to slow the spread of cases than in March due to the variant, meaning it could take more than two weeks from the start of lockdown for the peak to be reached.
Any peak that does occur would be seen several weeks later in hospitalisations and, subsequently, deaths.
Has the demographic of those hospitalised and dying from Covid changed?
The evidence here is mixed. While some doctors are reporting seeing more younger patients in hospital than in the first wave, data from the intensive care national audit and research centre suggests the characteristics of patients critically ill with Covid have not changed between the first and second waves.
Over the course of the pandemic, the majority of those who have been hospitalised and died have been 65 years or older. However, analysis of NHS England data appears to show that those aged 64 or younger are making up a greater proportion of hospital admissions than in the first wave.
According to the latest report, dated 31 December, the median age for those admitted to intensive care with Covid from 1 September was 62 years, compared with 60 years for those admitted up to 31 August, with 67% of the former group male, compared with 70% for the earlier cohort. Other characteristics are also similar, although the proportion of intensive care patients who are white has risen.
Are there any silver linings?
The arrival of vaccines means a growing number of people, particularly those most vulnerable to Covid, will gain protection against the disease, with the first dose offering some protection within about 12 days.
Last month Prof Jonathan Van-Tam told BBC News that the impact of vaccination could be dramatic. “If we can get through phase 1 [of the priority list] and it is a highly effective vaccine and there is very, very high uptake, then we could in theory take out 99% of hospitalisations and deaths related to Covid-19,” he said.
However, so far only 1.3 million people in the UK have had at least a first dose of vaccine and the impact of vaccination will take several weeks to show up in the data, with the effects likely to be seen first in death figures, and later hospitalisation statistics.
Prof Kamlesh Khunti, who sits on Sage and is also a member of the Independent Sage group of experts, warned that even with vaccination, masks, social distancing and other measures are likely to be needed for a long time. “It is months before we can starting thinking about stopping any of those,” he said.
“We need to get 70-80% of the population immunised to control the spread of the virus,” Khunti said.
But there are other positive developments: further drugs are being discovered that could help save the lives of the sickest Covid patients, while the approval of novel vaccine technologies means that even if new variants elude current Covid jabs, new vaccines can be developed relatively quickly.
Additional reporting by Niamh McIntyre
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