Not having "natural herd immunity" until a vaccine is developed makes testing & contact tracing even more important when opening up a society for business when facing a novel pandemic.
Have you updated your thoughts on the rate of spread of Covid 19? How would testing and tracing work in a city of say a million or more people when half the people infected don't even know they have it? I will tell you.. the effective rate of spread would have to be very low. Mostly likely so low... that the shutdown of low risk groups makes no sense.
Testing and tracing in a city of a million or more people already works just fine for diseases like TB when half the people infected don't even know they have it at the onset. They are able to snuff out TB outbreaks in western cities with proper public health testing & tracing. No different with COVID-19. Do proper testing and contact tracing like Germany has demonstrated and you can keep the R rate below 1 and number of infections low -- thereby broadly protecting society with reasonable measures. The entire purpose of proper testing and contact tracing is to keep the effective rate of spread very low. The Rnaught infection rate of COVID-19 with no mitigation is above 2, and most likely above 3. Some estimates have it at 4.2 to 6.8 in medical papers. This demonstrates the importance of driving it below 1 with proper testing and contact tracing. The infection rate is kept low by doing proper contact tracing, isolation and testing --- not by allowing "low risk" people to run about with no proper measures in place including quarantines for anyone who has been exposed & has not been confirmed to be negative.
I can tell you this. On Bloomberg TV about 2 weeks some top Public Health official said testing and tracing could work in London because the R) or effective rate of spread is less than 1. TB may work with testing and tracing in the US because the effective rate in the US in the study I just read placed it at 0.55. Whereas in China the R0 is closer to 4. I am willing to be Covid exhibits a similar pattern. The WHO numbers scared the hell out of you and others and they were not applicable to the US where we have much less TB ... TB and latent TB have been said to be a big risk for Covid hospitalization and death. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092233/
It's estimated that anywhere from 5% to 20% of the world's population contract the flu every flu season. I'm sure there was a measurable percentage of the 4,800 crew members that were showing COVID-19 symptoms from different causes. Besides that, false positives are only one side of the coin. It's also possible that the tests they were using weren't sensitive enough to detect minor levels of the virus still in their system. That would explain why it would look like they were reinfected a couple weeks later when they suffered a flair up of the virus. I'm just trying to look at this from a probability standpoint. It's highly improbable that someone would be reinfected by the same strain of a virus a few weeks after clearing it from their system, because they should have antibodies to stop that from happening. A small amount of testing failures seems a lot more probable.
You are in effect saying that someone that gets cured from a virus is re-infected? That defies established science that once, you get infected and get cured, you have immunity. Having had smallpox and measles as a child, never had it again. I was like 5 or 6 years at the time. Now, I am 62, so, like 56 years later, no re-infection, what are the chances any viruses once, cured will re-infect you all over again? It defies logic and science. More likely, a false positive and having symptoms which are similar to the common flu, colds or cough does not prove you got re-infected. More likely, you got mis-diagnosed as having the Corona Virus when you just had a bad cold? Faulty testing kits and no effort to re-test using multiple test kits using different criteria, was not undertaken. Common sense would suggest you do so. Otherwise, what are you relying on? Doctors can also, misdiagnose too you based on your illness. A doctor once, said I had a fractured left foot after he viewed x-rays he had taken. My left foot was hurting badly. I asked him if I needed a cast. No, it will heal on its own he said. What about the pain? Just take some Tylenol. A week went by and my left foot still hurt badly. No relief at all. So, I went back to the hospital, now had a different doctor take x-rays like the first one. This time the doctor said, I did not have a fracture. That was what the first doctor said. What you have he said was gout. He gave me medication and the left foot and the swelling went down and I got better. Yes, doctors make mistakes far often that you think. They are humans after all.
Yet another thing to worry about... the virus lying dormant for 10 weeks before you get a full blown case of COVID and land up in the hospital, or was it possibly acquired via a re-infection for a second time as the Queensland Premier Annastacia Palaszczuk told reporters... Authorities suspect Queensland woman carried 'dormant' coronavirus for 10 weeks before falling ill https://www.sbs.com.au/news/authori...t-coronavirus-for-10-weeks-before-falling-ill A passenger of the Ruby Princess who tested positive to coronavirus is suspected to have carried the "dormant" virus for almost 10 weeks before falling ill. The woman was diagnosed in Cairns on Monday, taking the total number of Queensland cases to 1057, with just 12 remaining active. Authorities suspect she is the latest coronavirus case to have carried the inactive virus and become sick weeks after exposure. Last week another woman in Queensland was diagnosed two months after returning from India. "We are monitoring that very closely to work out if it's directly related to the Ruby Princess or if it was acquired in some other way," Queensland Premier Annastacia Palaszczuk told reporters on Tuesday. A spokesperson for the health minister told AAP the woman had returned a negative result after a recent test and it was not possible she was contagious since she left the ship on March 19. The new case comes as the premier continues to stand firm on her decision to keep the state's border closed, despite the falling number of cases across Australia. The move has frustrated tourism operators who rely on interstate visitors, and leaders of the the southern states. Ms Palaszczuk will meet with key tourism stakeholders, as well as council, theme park operators and members of the hospitality sector to discuss a further easing of restrictions, particularly in restaurants and cafes. "If the COVID-safe plans are in place, they will be allowed to have more (people) in," she said, adding that numbers would depend on the size of the venue. "At the end of this month we'll be able to make that decision, but it's very positive."
We are well on our way to herd immunity. In ten days we will know with more certainty as during the past 96 hours tens of millions have mingled with each other in close proximity. Rate of infection is only relevant as it pertains to the spread throughout the general population. The more the better. 8 out of 10 will have no symptoms to speak of. Hospitalized and deaths are the only things that matter. If those two things don't spike and sustain high levels we are out of the woods. If they do, our world will be changed long term for the worse, much worse. We will know soon