28 Years Later?

Near the opening, there was a title card that read “28 Years Later”. Now I want to know if this is a certain Easter egg (this is a term used to describe a hidden surprise or extra feature included in film/tv or any electronic medium for a fan watching it to enjoy) considering the ‘28 Years Later’ movie by Danny Boyle is scheduled to be released next year.

I wouldn’t put it past Brad Peyton for this to have been done deliberate considering he’s a movie buff and Danny Boyle is one of his inspirations.

Think about it. They could have literally used any other number but they chose 28. Why? I don’t know if I’m overthinking this but I know I cannot be the only one who thought about this when they saw that title card.