– I urgently need a haircut… I really need a haircut…
– Have you already planned April 12?
– Are you going to the pub? Already!
– No, the haircut.
– Ah, not yet.
In this dialogue recorded at the end of March, who is in desperate need of a haircut but has made an appointment just to have a pint of beer, is UK Prime Minister Boris Johnson.
Like him, millions of Britons confined since January 5 are eagerly awaiting Monday April 12, when England enters a new phase.
Hairdressers, masseuses and similar professions that require a return to local work, but mainly restaurants, bars and cafes can be used outdoors.
In the 97 days between the total closure and the partial reopening, the situation of the Covid-19 pandemic in the country has been reversed.
From 58,474 new cases a day on January 4, the UK dropped to 2,762 last Wednesday (7). Daily deaths fell from 714 to 30 (using the seven-day average to rule out record flaws).
As the curves of the pandemic descended, so did the vaccination. From 4.3% of the population injected with the first dose on January 10, it reached 60.4% on Wednesday (7); more than 11% are already fully protected.
The situation is even better because more than 90% of people over the age of 80 have already been vaccinated, the age group where the risk of dying or developing serious complications from Covid-19 is greater.
These are reasons enough for Boris Johnson to toast his visit to the pub on Monday, but researchers at University College London (UCL) have decided to add one more. According to calculations released on Thursday on the 12th, the country would also achieve so-called herd immunity (when the percentage of immunized people in the population is high enough to stop the transmission of the coronavirus).
According to the mathematical study, the share of people vaccinated added to those who developed antibodies because they were cured of Covid-19 would reach 73.4%. As a result, the likelihood of an infected person finding a vulnerable person would be drastically reduced, reducing contagion.
Scientists who evaluated the UCL study, however, believe it may be overly optimistic. For Louise Dyson, professor of epidemiology at the University of Warwick, if the confinement was completely over and if contact rates between people returned to pre-pandemic levels, the contagion rate would hardly stop accelerating. .
According to Rowland Kao, who teaches data science at the University of Edinburgh, the reasoning must also take into account the geographic variation in vaccination levels.
“If two different areas with the same population have achieved 80% protection, the effect is one. But the picture changes if 80% is the average between one which has reached 100% and another is at 60%, mainly because people from one place move to the other, ”he illustrates.
Kao notes that people over 65 are relatively well covered by vaccination, which reduces the pressure on hospitals, but the data shows very uneven coverage between ethnic and income groups (minorities and more. poor were vaccinated at lower rates).
“These are also groups where individuals are more likely to be severely affected by Covid-19. Consequently, any assessment of collective immunity which does not take this heterogeneity into account would be too optimistic, ”explains the professor.
Another argument that can pour water into the beer of the British Prime Minister is that of the professor of epidemiology of infectious diseases Adam Kucharski of the London School of Hygiene and Tropical Medicine.
“There is still a lot of uncertainty about the vaccine’s effectiveness in reducing transmission, the duration of vaccine protection and the characteristics of the new variants,” he says, and all of these variables make it difficult to predict the degree of protection. . of a population. According to him, it is not clear how UCL’s calculations incorporate these uncertainties.
Kucharski also said estimates could be overly optimistic about how the population – and the pandemic – will behave when the restrictions are lifted. Boris may not have much to control the population, but he has announced measures to try to at least stop the pandemic.
From the 12th, according to government plans, anyone will be able to take two free tests per week – in countries where exams are charged, they can cost almost R $ 700.
But experts have warned that the measure will only work if people self-isolate when the result is positive – which requires a program to support those who must stop working.
Another idea under discussion is an immunity certificate (for those who have been vaccinated, tested negative, or have recovered from the disease), which would provide access to sports stadiums, nightclubs and sports facilities. other places that are often very popular. The idea would be to test it in an FA Cup final at Wembley Stadium.
According to government plans, stores, restaurants or bars could also apply for a certificate – but they would not be required to do so – when they can receive people inside, which shouldn’t happen before. May 17.
England has also announced a three-tier “traffic light” for international travel, banned at least until May 17. There will be different levels of quarantine requirements for countries designated as red, yellow, or green, but the lists of people in each category have yet to be released.
The passage to each new phase of the opening of British isolation undergoes “four tests” announced by Boris at the end of February: a significant drop in the number of cases, the ability to attend the National Health Service, a continuous progression of vaccination and the lack of Covid-19 variants to change the dynamics of the pandemic.
To avoid the red notes he took at the start of academy, Boris appears to be treating deflation the same way he dreams of Monday. “I can go to the pub and have a pint [cerca de meio litro] beer – cautiously, but irreversibly, ”he said, announcing the new stage of the reopening.