Covid-19 infections could double over Christmas, scientists advising the government say.
The warning comes in the final installment of files of the Scientific Advisory Group on Emergencies (Sage). The documents were presented to the government before a decision was made to ease Covid’s restrictions during the festive period.
“Notes on Festive Period” is written by the Scientific Pandemic Influenza Group on Modeling (SPI-M), which reserves the document as being based on preliminary models. The document contains stark warnings for a significant mixing of people in a short time.
“Any relaxation during the holiday season will result in increased transmission and increased prevalence, possibly to a large extent,” the document says.
They later add, “SARS-Cov-19 has shown that the rate of secondary attacks is high in households (with estimates of up to 50% in a household becoming infected by an infected member). Prevalence could easily double over a few days of the holiday season, with further multiplying increases as new infections return to their ‘routine’ networks. “
The warning comes as the government and Sage disclosed the R number specifically for England and the UK as a whole, now it was 0.9-1.0 for the first time since August. Due to the delay in the data, Sage says this figure reflects some of the impact of the last lockdown in England, but not its full effect.
The total R number masks significant differences in the UK. While R was revealed to be between 0.7 and 0.9 in the North West of England, it was 1.0 to 1.2 in the South East, suggesting that the epidemic was shrinking at first and remained stable or at the latter was growing.
But while there are growing signs that lockdown is starting to impact infection and hospital admissions, it may take several weeks for such changes to be reflected in the daily death toll. On Friday, 521 people in the UK had died of Covid.
Boris Johnson announced on Tuesday that three households could mix up to five days over Christmas, creating a “bubble.” However, Sage experts reveal in the files that Christmas bells will still be risky.
“If all households were to bubble with another household, the number of out-of-bubble contacts would have to be reduced to the April 2020 level (<1 external contact per person) to avoid exponential growth," a paper notes.
The experts also warn that forming bubbles may be better than limiting contacts to a certain number, but it’s crucial that people stick to just one bubble.
“Allowing people to form different bubbles over the festive period would be worse than confining them to a single bubble,” says the modeling team.
Sage experts believe that a key factor in reducing the impact of Christmas collaboration is to minimize the prevalence before the festivities – not only to reduce the chances of meeting someone infected, but also because an increase in the number of infections if the prevalence is already high is likely to be. have a greater impact on hospital admissions and deaths.
“Households can significantly reduce their risk of introducing an infection at an event by quarantining for two weeks,” they say. “This raises equality issues, however, as many families would struggle with this, including frontline workers.”
The documents also shed light on the time frame that the government has allowed mixing over Christmas. “Bubbling would be most effective if the time is limited to less than one generation of infection time (about a week),” write the modeling experts. Prof. Liam Smeeth, Professor of Clinical Epidemiology at the London School of Hygiene & Tropical Medicine, said: “A period of tiered action in December is now warranted to allow for a degree of social blending at Christmas that is so important to many. I suspect another circuit breaker will be needed in January or possibly February as Christmas will put such upward pressure on transmission speeds. “