By “effective” we mean, propaganda that is more successful at persuading someone to adopt someone else’s agenda:

“What really makes people trust VR more is that it creates a greater sense of realism compared to text and that creates the trustworthiness,” said Sundar.
….
That said, the immersive quality of virtual reality and 360-degree video may make the content more shareable, according to the researchers, who report their findings in the current issue of Cyberpsychology, Behavior and Social Networking.

Source: Virtual reality makes journalism immersive, realism makes it credible — ScienceDaily
VR appears to strengthen two key attributes of propaganda messaging:

1. The VR experience enhances credibility of the propaganda message
2. VR content may be “more shareable” than other content.

In other words, people are less likely to question the propaganda and are more likely to share it – further enhancing social media’s role as a frictionless platform for propaganda messaging.
Are we doomed? 🙂