Tag Archives: rapid spread

How UK PM Johnson decided to delay COVID reopening

By Alistair Smout

LONDON (Reuters) – British Prime Minister Boris Johnson on Monday delayed by a month his plans to lift the last COVID-19 restrictions in England after modelling showed that thousands more people might die due unless reopening was pushed back.

The move was due to the rapid spread of the Delta coronavirus variant, which is more transmissible, associated with lower vaccine effectiveness against mild disease and could cause more hospitalizations in the unvaccinated.

He said the extra time would be used to speed up Britain’s vaccination program – already one of the world’s furthest advanced – with two thirds of the population expected to have had two shots by July 19.

Here are the details behind the decision:

WHAT AND WHO ARE THE MODELS AND THE MODELLERS?

Models commissioned by the government showed that without a delay to the planned June 21 reopening, in some scenarios hospitalizations could match previous peaks in cases when ministers feared the health system could be overwhelmed.

Three models, made by the London School of Hygiene and Tropical Medicine, Imperial College London and the University of Warwick, fed into the government’s pandemic modelling subgroup SPI-M-O.

All three found that a delay would lower the peak of a new wave fueled by the Delta variant. A two-week extension would have a significant effect, but four weeks would reduce the peak in hospital admissions by around a third to a half, SPI-M-O said.

SPI-M-O will make fresh projections before July 19 when the full reopening is now expected to take place, with Johnson saying that he does not want to delay reopening again.

WHAT ABOUT THE VACCINES?

Britain has one of the fastest vaccine rollouts in the world, with over half of adults receiving both doses and more than three quarters receiving at least one, which has led some to question why restrictions need to be extended.

The modelers warned that while protection from vaccines was not perfect, without them, England would be heading back into lockdown.

Imperial epidemiologist Anne Cori told reporters that differences in who was eligible, in rates of uptake, and the fact that vaccine effectiveness was not 100%, all combined to create the possibility of a large wave of hospitalizations.

VACCINE AND DELTA

One worrying aspect of the Delta variant is evidence that it reduces protection from vaccines against symptomatic infection, although experts still hoped it would work against severe disease.

As Johnson announced the postponement, Public Health England published data showing shots made by Pfizer and AstraZeneca offer high protection against hospitalization from the variant identified in India of 96% and 92% respectively after two doses.

Asked if that data, released after the models were made, would have an impact on the projections, Cori said they had used different efficacy assumptions for their models, and PHE figures would help to narrow down the range of likely scenarios.

“The optimistic vaccine efficacy or perhaps the central (scenarios) are definitely more likely than the most pessimistic set of vaccine efficacies we had looked at,” she said.

WHAT ARE THE SOCIAL-ECONOMIC COSTS?

Many lawmakers in Johnson’s own party expressed dismay at the delay, with Steve Baker saying some people “increasingly believe they are never going to see true freedom again.”

Kevin McConway, emeritus professor of applied statistics at The Open University, said the delay would buy time to learn more about the Delta variant, and get more shots in arms.

But he said increased risks of opening on June 21 were hard to quantify, and economic costs were not being modelled with anywhere near the same rigor.

“I do wonder how the government can make good decisions on the balance between restrictions on what we can do, if they have detailed modelling of infections, vaccines, hospitalizations and deaths (including information on the likely uncertainties), but no detailed modelling (that I’ve seen) on the economic and social costs of the restrictions,” he said.

(Reporting by Alistair Smout; Editing by Josephine Mason and Alison Williams)

Delta coronavirus variant believed to have 60% transmission advantage: UK epidemiologist

LONDON (Reuters) – The Delta coronavirus variant of concern, first identified in India, is believed to be 60% more transmissible than the Alpha variant which was previously dominant in Britain, a prominent UK epidemiologist said on Wednesday.

British Prime Minister Boris Johnson has said that England’s full reopening from COVID-19 lockdown, penciled in for June 21, could be pushed back due to the rapid spread of the Delta variant.

Neil Ferguson of Imperial College London told reporters that estimates of Delta’s transmission edge over Alpha had narrowed, and “we think 60% is probably the best estimate”.

Ferguson said that modelling suggested any third wave of infections could rival Britain’s second wave in the winter – which was fueled by the Alpha variant first identified in Kent, south east England.

But it was unclear how any spike in hospitalizations would translate into a rise in deaths, as more detail was needed on how well the vaccine protects against serious illness from Delta.

“It’s well within possibility that we could see another third wave at least comparable in terms of hospitalizations,” he said.

“I think deaths probably would be lower, the vaccines are having a highly protective effect… still it could be quite worrying. But there is a lot of uncertainty.”

Britain has seen over 127,000 deaths within 28 days of a positive COVID-19 test, but has given more than three-quarters of adults a first dose of COVID-19 vaccine.

Public Health England has shown that the Delta variant reduces the effectiveness of Pfizer and AstraZeneca shots among those who have only received one shot, though protection is higher for those who have received both doses.

Ferguson said that up to a quarter of the Delta variant’s transmissibility edge over Alpha might come from its immune escape from vaccines, saying it was “a contribution but not an overwhelming contribution” to its advantage.

(Reporting by Alistair Smout; editing by Sarah Young and James Davey)