'Could be an Achilles heel': Why COVID-19 vaccines requiring two doses worry some expertshttps://nationalpost.com/health/could-be-an-achilles-heel-why-covid-19-vaccines-requiring-two-doses-are-worrying-some-health-experts
https://nationalpost.com/health/could-be-an-achilles-heel-why-covid-19-vaccines-requiring-two-doses-are-worrying-some-health-experts
