Lockdown: yes, no, maybe. The problem is why.

On this cold February Sunday, the most prominent Italian national newspapers' reading provides insights that we didn't see in a while. After the lottery on ministers of the new government, the catch click-phrase is back: "let's close everything, national lockdown, the English variant leaves no other choice". The situation is known to everyone. Skytg24 tells the state of the epidemic every day in "The Numbers of the Pandemic". We are in a stalemate. The curves of the various indicators are slowly falling. Everyone's attention must be maximum because it takes a little distraction to see the situation worsen again.

The graph we report shows a simple classification of the Italian regions according to two thresholds: intensive care occupation (above 30%) and incidence (above 250 per 100 thousand inhabitants). If a region exceeds one of the two thresholds, it becomes orange, if it crosses both red. Otherwise, it remains yellow. Nothing complicated, a simple representation, which, monitored weekly, provides some information on the epidemic's progress. We have seen worse times.

Today we talk about the lockdown, again. Why? With what goal? In analyzing the various opinions, it is precisely the goal that does not seem clear, nor even explicit. Let's try to imagine what objectives can be achieved through a lockdown.

Objective 1: local extinction of the epidemic. You want to eliminate the virus from the area of ​​interest. For this purpose, a total lockdown is useful, to get up to zero cases per day for a sufficient period (one / two complete incubation cycles, i.e. 14/28 days). Strict isolation and quarantine measures are obviously fundamental. Stringent epidemiological surveillance is subsequently indispensable, particularly on entrances from outside the territory.

Objective 2: mitigating the effects of the spread of the epidemic, with the minimization of deaths. The lockdown is not necessary, except as a last resort. A good Test, Track and Treatment / Isolation / Quarantine (TTT) strategy is sufficient. When the TTT capacity is lost in an area (there are now standardized indicators). A prompt and brief lockdown (limited to that area) is necessary until control of the situation is resumed.

Objective 3: mitigating the effects of the epidemic's spread to avoid the collapse of the health system. In this case, too, the lockdown is not necessary, except as a last resort. Serious monitoring (we have the indicators) of the pressure on the health system, linked to the definition of risk levels of collapse, generally avoids the lockdown.

Here http://dx.doi.org/10.23812/21-3-E it says "It has been noted that the spreading rate of the British variant could be greater than 70% of cases compared to the normal SARS-CoV -2 virus, with an R index growth of 0.4 ." As it is written, this sentence admits a substantial lack of strong evidence, obtained through well-designed studies and analyzed with solid statistical methods. We would not like to accept the idea that if one cannot explain something, one can blame the current virus variant.