After character "Domestic Biological Head Doctor Huang" publicly announces that "... we discovered a vaccine. Every one can get back to their normal lives," people ecstatically take off their masks. - In reality, having "discovered" or developed a vaccine wouldn't, of course, help anything before it could also be mass produced and widely distributed.
In a public announcement, character "Domestic Biological Head Doctor Huang" says, "I am happy to announce that we discovered a vaccine." - In reality, vaccines are never discovered, but they have to be developed, which takes at least five years, which in the past took an average of about 20 years, and which in some cases could not be achieved even after decades.