However, people also have some concerns about what the vaccine contains, its side effects and when they’ll be able to get it. The current coronavirus vaccine focuses on mRNA, or messenger RNA, which is found in your body. As for side effects of the vaccine, Berggren said they’re similar to those of a flu shot. Metro Health discusses planBerggren said most side effects of any vaccine are going to be apparent within about six weeks. So when it’s your turn to get the vaccine, Berggren says to make an appointment and don’t show up late.