What’s the meaning behind the effective, protective and safe joke circling Twitter? Let us break down the joke for you.

The tweet originated from comedian Ivo Graham, who tweeted it on November 23rd.

“Pfizer vaccine: effective, protective and safe.

Modena vaccine: effective, protective and safe.

Oxford vaccine: effective, protective, and safe.”

For some however, the joke wasn’t clear and went over a head or two. In fact, some even took the tweet at face value, thinking it was making a point of endorsing all the vaccines equally.

Don’t fret if you didn’t get the joke as we’re here to break it down for you.

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Effective, protective and safe joke explanation

The joke here lies in the use of an Oxford comma. If you look closely, the oxford vaccine description includes one, while the Pfizer and Moderna ones don’t.

An Oxford comma is a comma that comes before the ‘and’ at the end of a list. The punctuation often splits linguists, some of who favour the comma while others feel it’s unnecessary.

As an example, here’s a time when the comma would come in handy:

“We invited the dogs, Justin Bieber and Usher.”

“We invited the dogs, Justin Bieber, and Usher.”

The sentence without the Oxford comma could lead readers into thinking the dogs are called Justin Bieber and Usher. While the one with makes it clear that the dogs, Justin Bieber, and Usher are three separate things who are all invited.

Although the comma in “effective, protective, and safe” joke doesn’t change the meaning, it’s a play on the linguistic rule.

Photo by MLADEN ANTONOV/AFP via Getty Images

Reactions to the joke

For those that got the joke, the tweet was shared applauding the subtlety of it:

Others were confused by the effective, protective and safe joke:

While some took it as an opportunity to voice their views on the vaccines, not realising it was a joke:

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