This is a pretty amazing development, if confirmed. It has been a while but I have posted before on studies suggesting that the epidemic began earlier than is commonly believed, in Asia, Europe and the US. The evidence included satellite imagery of hospital traffic in China, stored wastewater samples, stored respiratory samples and data on visits and hospitalizations for influenza-like illness in certain locations last fall. These studies all suggested that CV-19 could have been circulating as early as the fall of 2019. Since we know the Chinese are perfectly capable of simply lying, this possibility is plausible. Now comes a study from Italy that would appear to very strongly indicate that this strain of CV-19 or something very close to it was circulating in Italy as early as last September.
The study is published in the Tumori Journal, an Italian research publication. Not a fly-by-night journal, and I had to pay $41 to see the full article. Appears to have been peer-reviewed, the authors have a pedigree. Here is the abstract link. (Italian Article) The researchers looked at blood samples from 959 asymptomatic individuals participating in a lung cancer screening trial between September 2019 and March 2020. Antibodies to the receptor binding domain of CV-19 were screened for. That area is fairly different compared to the similar area in seasonal coronavirus, so cross-reactivity seems to be an unlikely explanation. Beginning in September 2019, the antibodies were detected in 111 of the samples. Interestingly, as you might expect in a lung cancer screening trial, over 75% of the persons in the study were smokers and over 90% had been and you will recall that some studies have suggested smoking may have an association with less likelihood of severe infection. The earliest detection of antibodies was geographically consistent with the initiation of the epidemic in the hardest hit areas of Italy. Neutralizing antibodies were discovered in six of the positive samples, which seems low since they were targeting receptor binding domain areas, but it may be consistent with the early versions of the strain being somehow less infectious.
Here is a link to an article from Italy back in the spring of 2020 in which researchers had speculated that an uptick in severe flu and pneumonia in the fall of 2019 might have actually been caused by CV-19. (Flu Article) According to Italian researchers there were hundreds more cases than usual from October to December and some people died.
What are the implications? If accurate, and if China is still the putative source for CV-19, the strain must have emerged and infected humans in August 2019 at the latest. At that point there were no travel restrictions, I was actually in Japan in September of that year. The virus would easily have been traveling around the world. Perhaps the early versions of the strain were less infectious, it only takes a genetic change of a few base pairs to make a significant difference. And as we know, the vast, vast majority of infections are asymptomatic or mild even with current strain. More severe illnesses would have likely been viewed as influenza or another virus prior to the Chinese being forced to come forward with the truth about the new pathogen.
So it is possible that CV-19 could have been spreading at some level, not really noticed because it wasn’t causing that much severe illness and the conditions weren’t that favorable to the virus. Then it begins to pop in late fall/early winter in China and the authorities try to suppress the truth, but when it comes out, that is when people think it began. The low-level spread with largely harmless infections might have been occurring in a number of places around the globe, mostly where there are large international airport hubs. There are hundreds of research project at any one time collecting blood samples so should be easy enough to verify the accuracy of this paper and the blood samples should be tested for T cell response as well.
Much earlier spread in the fall in Asia, especially of a slightly less infectious version, might help explain the seeming paucity of cases there now. This might also mean there is a higher prevalence in the population than we currently believe. Antibody surveys may not pick up these mostly asymptomatic infections, but T cell surveys might.