Self-spreading vaccines are potentially dangerous and difficult to manage, and are “genetically too unstable to be used safely and predictably outside contained facilities,” write the authors, led by Filippa Lentzos from King’s College London and Guy Reeves from the Max Planck Institute for Evolutionary Biology.

This is not just their opinion, the authors argue. Rather, it’s an “evidence-based norm” that’s been around for decades, but this “norm now seems to be challenged,” they write. The result is an increased potential for “risky research on lab-modified self-spreading viruses,” according to the report. This could lead to a normalization of the concept and eventual real-world use without the proper safeguards, the scientists argue.

“Self-spreading vaccine research continues to proceed despite a lack of new information that would compellingly refute long-standing evidence-based norms in virology, evolutionary biology, vaccine development, international law, public health, risk assessment, and other disciplines,” the biologists write.