There are already long term studies (in France for instance there is the constance cohorte https://www.constances.fr/cohorte/presentation-constances.php https:/

There are already long term studies (in France for instance there is the constance cohorte https://www.constances.fr/cohorte/presentation-constances.php https://www.constances.fr/cohorte/presentation-constances.ph...) that ask volunteers to come and get tested for a lot of things. This data is being looked at and it seems there were already covid cases months before reports of cases in Wuhan https://www.francetvinfo.fr/replay-radio/samedi-investigation/covid-19-des-francais-contamines-bien-avant-les-premiers-cas-officiels-temoignent-pour-la-premiere-fois_4348403.html https://www.francetvinfo.fr/replay-radio/samedi-investigatio....