why is making vaccine for covid19 taking so long?

I recently watched movie outbreak and korean movie flu. In both movies, toward to end, one monkey with antibody (in outbreak) and one person with antibody (in flu) solved the whole problem so quickly and so easily, it seems. That made me wonder, I know they are just movies and I'm not epidemiologist. But, why is making vaccine for covid19 taking so long and why does it seem so difficult to make it? Why can't they just gather antibody from peoples who recovered on their own( there seem to be so many of them) and study it and develop vaccine? 

I don't think they can make vaccine within a day or wk like in movies. But, it has been over 6 months already and still no vaccine? Or making vaccine was easy and there are proposed vaccines out there but strict regulation and approval process is hindering it from becoming public? 

trekkie7062020-06-06T18:02:40Z

depopulation! Another pandemic will show up soon. A famine is coming! This is what Holy Spirit told me. We are in the last days. This is what Jesus call the days of sorrows. Prophet John Paul Jackson told of a pandemic back in 2008. His stuff is online if you want to see what else he said. The riots will get worse when the economy tanks. God is going to make things on earth so bad that people will cry out to Him and repent of their sins. A lot of Christians think that God will rapture us out before the bad stuff hits. We are His mouth.

?2020-06-06T17:56:00Z

That's the difference between movies and real life.  We need to develop a vaccine that gives you immunity to the coronavirus that causes covid-19.  A feature of the other coronaviruses is that they mutate - that's why you cannot become immune to the common cold.  So you have to play your hunches and create a vaccine.  Then you try it out on rats - you give them the vaccine, wait a week, then inject them with coronavirus.  If the vaccine stops the virus infecting them you try it on humans.  However, you can't then give the humans a dose of covid-19 since there's a risk it could kill them.  So you wait a month or so and if none of your test group catches covid-19 you may have a working vaccine.  Then you have to create enough of the active part of the vaccine so you can manufacture billions of doses.  It ain't instant.