After HIV was discovered as the cause of AIDS, HHS Secretary Margaret Heckler was quoted as suggesting that a vaccine would be developed within two years. That was 1984. More than 35 years later, despite enormous effort, there is still no effective HIV vaccine. (Now there are very effective HIV drugs, however.)
Vaccines aren't created by magic or boasting. They require science, well designed and executed trials, and patience. As a group, viruses employ a variety of tricks, some viruses such as HIV being much harder than others to outwit.
Even if a safe, effective, FDA-approved COVID-19 vaccine appeared tomorrow, it would take many months for it to affect the pandemic because of challenges in manufacture, distribution, --and trust. As long as some people refuse to social distance and refuse to wear a mask, the virus will continue to spread out of control, likely killing ANOTHER 200,000 people just by the end of this year. Premature reopening of schools and businesses, not to mention holding crowded maskless rallies, guarantees more infections and more deaths as some leaders try to manage by calendar instead of by data.
At this time, despite enormous ongoing effort and political hype, defeat of the pandemic by vaccines is little more than a fantasy. But as Emory's Dr. Carlos Del Rio recently exclaimed, "We have a vaccine already--it's called a mask!"