Back in January, when the lockdown was being put in place in Britain, I wrote a piece for this website trying to imagine future trajectories. I started with the assumption that, since COVID-19 is a respiratory virus, it would probably behave in the same seasonal manner as other respiratory viruses. Most notably, the flu. I called this “the flu hypothesis”. Using this simple reasoning I then went and examined what different types of flu seasons looked like and used these to then discuss what government responses might be in the event of each. Broadly speaking, I found two types of flu season. One I referred to as “gradual”; the other I referred to as “aggressive”. In the case of an aggressive flu season, cases tended to accelerate rapidly toward the end of December into January. These would then peak in mid-January and after that cases would burn out. In the case of a gradual flu season, cases would not accelerate quickly at all. They would creep up in early winter, rise a little in January and then either settle back down or continue to climb right through March-April. Simply looking at previous flu seasons, I gave an estimated probability of an aggressive season of around 25-33% and an estimated probability of a gradual season of around 66-75%. By the end ...