No Vaccine is going to be on the market for 12 to 18 months, that would be January 2021 to July 2021. Do you expect the country to stay locked up for that long? And keeping people in lockdown makes no difference to the people working to develop a vaccine, why would it?
Any drug or biological has to go thru a three step procedure First it is tested on a small group to see if it safe to use. That takes months. Then a second larger group is used to determine the correct dosage and to further look for side effects. More months go by. Lastly a much larger group is used to further check for safety and whether the stuff does what it is supposed to do, delivery immunity in this case. Many more months for this stage. This normally takes years to do and costs hundreds of millions of dollars. All of this happens after extensive animal testing.
It can be compressed to the mentioned 12-18 months in an emergency. If you think this is overkill the French did a trial not to long ago that killed many of the participants right then and there, before they could get the needle out of their vein, and permanently injured many of the others. Mice are not people and because something may seem to work in a rodent does not mean it will in people.
