I agree. I don't think South Korea having fals e positives says anything about protection from differing strains. As far as I know there are at least 3 with significant changes. Whether that affects immunity I do not know. Also, nothing in this article shows any data on waning immunity to a single strain which is common with other coronaviruses. That headline is misleading. Nothing has been concluded other than South Korea had a bunch of false positive tests.