Shameless plug, but if you're in the SF Bay Area and want to learn more about GDPR, we're throwing an educational event on Wednesday 2/7: "GDPR: 4 letters, big trouble? Get up to speed on EU data privacy regulation" https://www.eventbrite.com/e/gdpr-4-letters-big-trouble-get-...
Looked at the paper, answer: that's what happens when vulgarization of scientific discoveries is so bad that it removes the actual discovery from the paper. Apparently the author discovered the existence of memory t cells when writing that article.