"They have been able to develop these tactics only because social-media companies have been happy for the key players in this anti-vaxx industry to use their services to recruit new followers and spread their lies further than ever before. As a result, there is an online infrastructure of anti-vaccine websites, Facebook groups, YouTube channels, Instagram pages and Twitter accounts with a combined audience of 59 million."

https://www.nature.com/articles/s41591-021-01260-6

Dismantling the anti-vaxx industry - Nature Medicine

Investigations show that those spreading misinformation that undermines the rollout of vaccines against COVID-19 are well financed, determined and disciplined. To counter their activities, we need to understand them as an industry actively working to sow doubts about the deadliness of COVID-19, vaccines and medical professionals’ integrity.

Nature
"The term ‘anti-vaxxer’ may evoke images of a conspiracy theorist in a grimy basement or a disheveled figure on a crate railing against ‘microchips’ and ‘global plots’. In reality, the key protagonists in the ‘anti-vaxx industry’ are a coherent group of professional propagandists. These are people running multi-million-dollar organizations, incorporated mainly in the USA, with as many as 60 staff each."