Which government you are talking about here ?
OP is talking about the federal government of Nigeria, here is a link to get the full story if you like:
https://www.premiumtimesng.com/news/headlines/460721-updated-covid-19-nigerian-govt-imposes-curfew-other-new-restrictions.htmlImo, it's an absurd sort of curfew as well, but the thing is there is a high level of insecurity in Nigeria atm, and the Nigerian Police force are actually struggling to curb this very issue, thus I think the government have imposed this curfew on the grounds of insecurity, more than that of covid-19. Having said that, Vaccination is on going in Nigeria, and to the best of my knowledge it's moving at a reasonable speed, neither has there been any recent massive spread of covid-19 in Nigeria. It does not come to be as a surprise at all, the Nigerian government are having quite a lot of issues on it's hands, and this curfew is a response to that, and not the pandemic.