Fact Check-COVID-19 vaccines using mRNA do not send the immune system into ‘perpetual overdrive’ by instructing cells to create the spike protein over and over again

A meme shared on social media that suggests mRNA vaccines trick the body into creating virus proteins “nonstop forever and ever” contains false information. It shows a lack of understanding of how these vaccines work.

The claim was included in a Facebook post shared on March 8 among a group that describes its members as “freedom fighters” who want to “stop the new normal”. The post reads: “What happens when your body’s own cells are programmed to keep making the protein of an invader, nonstop, forever and ever, with no programmed end date?

“What happens when your immune system is in perpetual overdrive, tricked into believing there’s a pathogen that just never goes away?” (here)

The post itself does not specifically mention mRNA; however, it describes the main part of the process these vaccines undertake, ie: instructing a cell to create a protein (here). Comments written in response also demonstrate that other Facebook users understand the post is referring to mRNA vaccines, such as those developed by Pfizer/BioNTech and Moderna.

While it is true to say these vaccines prompt cells in the body to create the spike protein that surrounds COVID-19, it is not true to say this is a process that happens repeatedly, pushing the immune system into “perpetual overdrive”.

The mRNA that instructs cells to create the spike protein is broken down by the cell shortly after the protein is synthesised (here). The protein itself, meanwhile, is broken down when it leaves the cell and is met by the immune response (here, here). As explained by Pfizer, this approach trains the immune system to recognise and respond appropriately should it encounter the virus in the future (here).


False. COVID vaccines using mRNA do not programme cells to repeatedly produce spike proteins. The mRNA instructs cells to make the protein and is broken down by the body shortly thereafter.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here .