UNICEF Admonishes Nigerians to Get Another Round of Vaccine

Aren’t vaccines meant to be a one time thing that will keep you immune to virus and what nots?

Why then did the United nations Children’s Funds, UNICEF, urge Nigerians to take a second dose of the vaccine to get a stronger immunity from the virus.

This directive was birthed out of the need to save lives, so it is ok to say that the intentions of UNICEF is for the good of Nigerians, but what could really have gone wrong with the first set of vaccines that Nigerians have to get another dose?

What is your reaction to this? Can we even be sure that the vaccine works at all?