"How do you tell vaccinated from unvaccinated if…

The COVID-19 (coronavirus) pandemic resulted in mask wearing. Vaccines were made available in 2021, and some mask restrictions were dropped. A riddle was posted on Reddit—Jokes on May 14, 2021:

Q: How do you tell the difference between a fully vaccinated person and an unvaccinated person if they aren’t wearing a mask?
A: Ask them who won the election.

That is, a supporter of Democrat Joe Biden would probably be vaccinated, and a supporter of Republican Donald Trump probably would not.

The joke had been told a day earlier. “Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?” was asked by Katie S. Phang on Twitter on May 13, 2021. “Ask them who won the election, that’s an easy way to tell” was posted on Twitter by Shannon Snow on May 13, 2021. “ask them who won the election” was posted on Twitter by Masks, Please! Get the Vaccine, Not the Virus. “Ask them who won the most recent presidential election” was posted on Twitter by Patrick Chesney.

Wikipedia: COVID-19 pandemic
The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in December 2019 in Wuhan, China. The outbreak was declared a Public Health Emergency of International Concern in January 2020 and a pandemic in March 2020.

Twitter
Katie S. Phang@KatiePhang·May 13
Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?
Shannon Snow
@shannonsnow34
Replying to @KatiePhang
Ask them who won the election, that’s an easy way to tell.
2:25 PM · May 13, 2021·Twitter for iPhone

Twitter
Masks, Please! Get the Vaccine, Not the Virus.
@SaltCreekBrews
ask them who won the election
Quote Tweet
Katie S. Phang
@KatiePhang
· May 13
Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?
3:19 PM · May 13, 2021·Twitter Web App

Twitter
Patrick Chesney
@pvchesney
Ask them who won the most recent presidential election
Quote Tweet
Katie S. Phang
@KatiePhang
· May 13
Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?
4:21 PM · May 13, 2021·Twitter for iPhone

Twitter
Đɇnnɨs Đɇŧwɨłłɇɍ
@drgonzo123
Ask them who won the election.
Quote Tweet
Katie S. Phang
@KatiePhang
· May 13
Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?
5:35 PM · May 13, 2021·Twitter for iPad

Reddit—Jokes
Posted by u/RichRichieRichardV May 14, 2021
How do you tell the difference between a fully vaccinated person and an unvaccinated person if they aren’t wearing a mask?
Ask them who won the election.

Twitter
𝕊𝕦𝕟𝕕𝕒𝕖 𝔾𝕦𝕣𝕝
@Sundae_Gurl
Pro tip: If you can’t tell the difference between a vaccinated person and an unvaccinated person if they’re not wearing a mask, just ask them who won the election.
1:56 PM · May 14, 2021·Twitter Web App

Twitter
Đɇnnɨs Đɇŧwɨłłɇɍ
@drgonzo123
Ask them who won the election.
Quote Tweet
Katie S. Phang
@KatiePhang
· May 13
Sooo…how does one tell the difference between a fully vaccinated person and a not vaccinated person?
5:35 PM · May 13, 2021·Twitter for iPad

“How do you tell vaccinated from unvaccinated if they aren’t wearing masks?” (joke)