1. In a press conference beamed across the nation on March 12, a bullish Boris Johnson announced that the government’s coronavirus strategy was to ‘flatten the peak’ of cases, or in the prime minister’s more flamboyant words, to ‘squash the sombrero.’
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3. The goal, Mr Johnson explained, was not to suppress the virus entirely, but to keep infections at a lowish level to avoid overwhelming health services and prevent a deadly second wave.
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5. At that point, just eight people had died in Britain from the virus out of the 590 who had tested positive.
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7. Lockdown was more than 10 days away, and the government was still hoping that herd immunity could be achieved. A day after the press conference, Sir Patrick Vallance, the Chief Scientific Adviser, gave a television interview suggesting that 60 per cent of people would need to become infected to protect the population.
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9. Yet after Imperial College modelling suggested such a ‘mitigation’ strategy could bring 250,000 deaths, the Government made a rapid volte face, imposing strict social distancing measures and closing businesses and schools on March 23.
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11. The impact of such extreme suppression means that a second peak, far higher than the first, is now a near certainty and that has major implications for how Britain must exit the lockdown if such a catastrophe is to be avoided.  
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13. Here is what we know about a second wave and how it impacts the future:
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15. The two peaks
16. In the first graphs, shown by Mr Johnson in March, ‘squashing the sombrero’ would cause the first peak to come in the summer, towards the end of May.
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18. The rounded peak appeared to be about half the size of that expected if the disease was left to run rampant through the population.
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21. Under that scenario the NHS would be able to cope and the virus would not present a problem later in the year.
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23. Sir Patrick told journalists: “We want to… not suppress it so we get the second peak and also allow enough of us who are going to get mild illness to become immune to this to help with the sort of whole population response, which would protect everybody.”
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25. However, under the current suppression plan, the trajectory of the disease has changed dramatically, with the peak moving to the middle of December. Alarmingly it appears every bit as high and deadly as the unmitigated wave that the government was so keen to avoid.
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28. Although experts believe that we have now peaked in the first wave, it is actually only a very low level of what could happen if lockdown is lifted without any means to suppress a second, far more deadly wave.
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30. Prof Neil Ferguson, of Imperial College, who led the modelling and who sits on The Scientific Advisory Group for Emergencies (SAGE) said: “There is almost no herd immunity and a very large risk of a second peak if we relax current measures without something to put in their place.”
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32. Compliance
33. One of the problems of Britain’s lockdown strategy is just how effective it has been.
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35. Suppression modelling was based on all households reducing contact outside of the household, school or workplace by up to 75 per cent. Workplace contact rates were to reduce by 25 per cent
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37. On April 13, the Government released its first graphs showing how the public was complying to lockdown. Workplaces were down 54 per cent and retail and recreation down 85 per cent.
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39. Likewise, people appear to be doing better at self-isolating that was expected. It was assumed that just 70 per cent of people with symptoms of coronavirus would stay at home as instructed, but research by health experts Evergreen Life, shows in most areas of Britain, more than 90 per cent are complying and even in the worst areas 75 per cent are still staying put.
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41. Although the modelling predicted that all schools would shut, it assumed 25 per cent of universities would remain open.
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44. Data published by the Department for Education this week showed that less than one per cent of children are going to school every day despite estimates from ministers that it would be up to 20 per cent.
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46. Likewise, it was thought that 50 per cent of people diagnosed with the virus would stay in quarantine for 14 days. Yet there is little evidence of people breaking quarantine and powers of arrest have now been given to police to stop it from happening.
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48. A small study from the Centre for Mathematical Modelling of Infectious Diseases at the London School of Hygiene and Tropical Medicine (LSHTM) found people had cut contacts by around 73 per cent, roughly in line with government expectations.
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50. While such compliance has been excellent at keeping the virus under control, leading to noticeable downturn in cases in the past week, it means few people are building up immunity.
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53. In the critical Imperial Paper published on March 16, scientists warned that once restrictions were relaxed infections would inevitably begin to rise again and the bounce back would be far worse if suppression was too extreme.
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55. “The more successful a strategy is at temporary suppression, the larger the later epidemic is predicted to be in the absence of vaccination, due to lesser build-up of herd immunity,” the researchers warned.
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57. Antibodies and immunity
58. Experts on the Government’s Sage committee now believe that only about 5 per cent of the population has been infected with the disease and that there is ‘almost no herd immunity’ in Britain.
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60. Under the government’s mitigation strategy, the reproduction - or ‘R’ - number, would reduce dramatically, but not to below one, so cases would rise, but only slowly, until hitting a peak.
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62. Under the suppression strategy, the reproduction rate falls from around 2.6 to below 1 and the virus dies away. But reducing infections now can store up problems for the future.
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64. The government is currently carrying out a testing programme to determine how many people in Britain have recovered from the disease to work out current immunity level, but so far it has not published the findings.
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66. Several studies have now put it at roughly six per cent and new results this week from the The Pasteur Institute show just 5.7 per cent of the French will have contracted coronavirus by the time the country starts lifting lockdown next month.
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68. The institute researchers warned of a high risk of a second wave unless drastic social distancing is maintained.
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71. Karol Skiora, a private oncologist and Dean of Medicine at the University of Buckingham has been carrying out his own antibody testing and believes that between eight to 10 per cent of people are likely to have had coronavirus so far.
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73. “We’re nowhere near herd immunity,” he said. “We could definitely have a second peak. You look at countries like Austria where they have opened their garden centres and small shops a week ago and they seem to have more cases again, so it is a real worry.”
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76. Waiting for a vaccine
77. Imperial College predicted that strict lockdown measures would be needed for at least five months, but they also warned that restrictions and widespread monitoring would have to stay in place until a vaccine was available, to prevent a second wave.
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79. Dozens of research labs across the globe are now working on vaccines and a team at Oxford believe they could have a viable jab ready by the autumn.
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81. Yet scaling up will present a problem and it is likely that only frontline workers will be given vaccines initially leaving the general public waiting until at least next year. That delay means there will be restrictions such as social distancing in place for many months to come.
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83. Sir Jeremy Farrar, a member of the government’s Sage group and the Director of the Wellcome Trust said the disease would not be going away anytime soon and future waves were likely.
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86. “We must assume and prepare for the fact that this is not a discrete one off episode,” he said.
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88. “My belief is that this is now an endemic human infection. It is likely that this is here with the human race for the future. We’re going to have to find ways to deal with that.
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90. “The real moving forward is we have to have new tests, we have to have drugs that treat this infection, and critically we need to have vaccines so we can prevent what we should assume are future waves.”
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92. Nightingale hospitals
93. In recent weeks, journalists have questioned why the government is continuing to invest in huge numbers of intensive care beds at Nightingale Hospitals while cases are on the decline.
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95. The possibility of a second peak is likely to be the reason.
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97. While the current epidemic appears to have stabilised below 1,000 cases a day, modelling of a second wave suggests that it could be far higher if it is not brought under control through mass testing, contact tracing and isolation after lockdown.
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99. Asked whether the Nightingale Hospitals were being kept for a possible second wave, a Downing Street spokesman said: “I am certainly not aware of any plans to stand down these Nightingale Hospitals and some are still being built.”
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101. Ending lockdown
102. Fears of a second wave of coronavirus has made governments around the world nervous about lifting their own lockdowns too early and too quickly and Britain is no exception.
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104. A safety net of widespread testing, contact tracing and isolation of those infected must be in place to ensure that cases are not allowed to rise, while ‘squashing the sombrero’ of a second peak may now be a viable option.
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106. Ilan Kelman, Professor of Disasters and Health, University College London said: “A second peak of infection could be manageable if we protect those who are vulnerable, treat those who get sick, do not reduce other medical services, and meet all healthcare worker needs.
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108. “Another possible strategy is a staged stand-down of lockdown to flatten a second peak, provided that those who are told to remain in lockdown, or who cannot work because of it, are given all the support they need to avoid difficult effects of being isolated while others resume life.”
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110. In China, a spike in infections after weeks of falling rates has forced the authorities to impose new restrictions.
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112. In the north-eastern city of Harbin a 22-year-old university student who returned from the US was identified as the source of more than 40 new infections, while Chinese citizens returning from Siberia via the border town of Suifenhe led to more than 400 confirmed new cases.
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114. The examples show the huge problem in restarting life again after a strict lockdown when so few of the population are immune.
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116. In Germany, the country credited with keeping its outbreak under tight control through its use of extensive testing and contact tracing has seen a rise in deaths as the country was re-opening some small shops and preparing for children to return to school from May 4.
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118. The director of the US Centers for Disease Control and Prevention warned on Tuesday that any second wave of coronavirus was likely to be even more serious if it coincided with the start of flu season.
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120. Robert Redfield told The Washington Post: “There’s a possibility that the assault of the virus on our nation next winter will actually be even more difficult than the one we just went through.”