In a peer-reviewed paper now published in Biometrics, I find that, in all three cases, Covid-19 levels were probably falling before lockdown. A separate paper, with colleague Ernst Wit, comes to the same conclusion for the first two lockdowns, by the alternative approach of re-doing Imperial College’s major modelling study of the epidemic in 2020. In light of this, the Imperial College claim that new infections were surging right up until lockdown one — causing about 20,000 avoidable deaths — seems rather questionable.

Source: Covid and the lockdown effect: a look at the evidence | The Spectator

Elsewhere, last November, a Harvard epidemiologist said that anyone questioning lock down policies should be held “for some form of accountability” and said those questioning lock downs are connected to right wing interests.

It can be difficult for a society to make forward progress in finding the truth when questions are prohibited and censorship is common.

While the world awaits a widely available COVID-19 vaccine, availability of testing is limited in many regions and can be further compounded by shortages of reagents, prolonged processing time and delayed results. One approach to rapid testing is to leverage the volatile organic compound (VOC) signature of SARS-CoV-2 infection. Detection dogs, a biological sensor of VOCs, were utilized to investigate whether SARS-CoV-2 positive urine and saliva patient samples had a unique odor signature. The virus was inactivated in all training samples with either detergent or heat treatment. Using detergent-inactivated urine samples, dogs were initially trained to find samples collected from hospitalized patients confirmed with SARS-CoV-2 infection, while ignoring samples collected from controls. Dogs were then tested on their ability to spontaneously recognize heat-treated urine samples as well as heat-treated saliva from hospitalized SARS-CoV-2 positive patients. Dogs successfully discriminated between infected and uninfected urine samples, regardless of the inactivation protocol, as well as heat-treated saliva samples. Generalization to novel samples was limited, particularly after intensive training with a restricted sample set. A unique odor associated with SARS-CoV-2 infection present in human urine as well as saliva, provides impetus for the development of odor-based screening, either by electronic, chemical, or biological sensing methods. The use of dogs for screening in an operational setting will require training with a large number of novel SARS-CoV-2 positive and confirmed negative samples.

Source: Discrimination of SARS-CoV-2 infected patient samples by detection dogs: A proof of concept study

Ali H. Mokdad, a professor of Health Metrics Sciences at the institute, estimates 85% of the population would need immunity to the virus to achieve herd immunity because it is so contagious. But only about 65% are likely to have immunity by the winter, he said, because children younger than 16 aren’t currently eligible for the vaccine and many Americans don’t want to take it. More contagious variants of the virus that may evade some of the vaccines’ protection add to the concerns.

“We will reach herd immunity, but not before this winter,” Mokdad said. He expects the virus to subside over the summer and fall but to return in winter again with the onset of cold, drier weather more favorable to its spread. It’s unlikely to drive a surge as bad as last winter’s, he said, but it’s likely that health officials will need to reimpose travel and mask requirements and restrictions on gathering.

Source: Gov. Newsom: COVID herd immunity ‘illusory.’ Is he right?

As noted here previously, lock downs may have some usefulness if applied very early – but cannot be implemented for long periods of time, and generally not over huge geographic areas.

Simple point: In the U.S., 71% of the workforce is declared “essential”. We still need food, water, electricity, health care – plus all the support services necessary to keep those running – including agricultural, trucking/transportation, vehicle repair, specialized manufacturing and so on. To keep society functioning – and avoiding other problems that would develop – requires that many people continue to work.

To illustrate how difficult it is to truly “lock down”, I read long ago that most towns have at most three days worth of food on grocery story shelves, in local warehouse distribution centers, and on incoming trucks. After that, we run out of food (except for those that stockpile inventories at home).

For practical reasons, lock downs are not a sustainable solution.