Paul Offit, director of the Vaccine Education Center and a member of the Food and Drug Administration's vaccine advisory board. "That means one out of every 20 people who get this vaccine could still get moderate to severe infection." - Article
That quote from the article is wrong. I've read extensively on the vaccines and their trials. The Pfizer and Moderna vaccines have been shown to prevent SEVERE infection among their trial participants. Of course there will always being outliers so as the vaccines are rolled out there will be some, who for whatever reason, has a severe case.
I've received the Astra Zenica Vaccine. It's a 2 dose regimen also. I enrolled in the trial they are conducting in my area.