People ask about the prospects for a vaccine for SARS-CoV-2.
The NYT had a good article about it about a month ago.
The history of vaccine development is a series of long drawn-out and frequently failed attempts. The idea that we throw everything at this problem and it's just going to work, is pie-in-the-sky. The optimistic experts say "maybe we will get lucky."
The proposals that would move the fastest are for DNA and RNA vaccines. These are vaccines that would contain (for example) the gene for the Spike surface protein of the virus, with accessory elements giving high expression.
They would either be mRNA (modified to be resistant to breakdown) or DNA.
But you should be aware that no DNA or RNA vaccine has been licensed for humans, period. There is one for West Nile Virus in horses. Many have been tried but they frequently don't elicit neutralizing antibodies.
One problem is efficiency. The nucleic acid just doesn't get into cells very well. People are trying gene "guns" to improve efficiency: the nucleic acid is bound to small metal microbeads, and propelled into your arm with compressed helium.
Moderna is an RNA vaccine that is in ongoing Phase 1 clinical trials, and has been approved to start Phase 2 even though the results from Phase 1 aren't known yet. Phase 3 is expected to begin in early summer.
Summary
Phase 1: Small N. Is the vaccine grossly toxic or relatively safe?
Phase 2: Medium N. Is the vaccine effective?
Phase 3: Large N Is the vaccine very safe and also effective?
Analysts are even wondering where they are going to get all the vials they will need to put the vaccine in, and the syringes and needles for injections. It's a real problem.
