During the first lockdown (UK), and at the height of the pandemic, there was a video doing the rounds, with a group of "doctors" from the USA, who were proclaiming that the virus was not dangerous, and that the upcoming vaccine programme was unnecessary as Covid could be cured. My brother's girlfriend posted it on FB, which is where I first saw it (not for long, I reported every single post of hers which contained misinformation, she soon got the message and buggered off to Telegram, to join the rest of the swivel-eyed loons
)
I noted the name of each of the doctors, and less than 10 minutes on Google showed that each and every one was an "alternative" practitioner, none worked in public health or medicine, and most were selling vitamins and potions on their websites, with claims of "boosting" your immune system, or "killing viruses" etc, etc.
I'm not a researcher, nor am I particularly clever. But it's not hard to find evidence that these conspiracy theorists aren't really reliable sources of information. I think the lockdowns did a lot of damage to the already fragile mindset of some people. Boredom also has a lot to answer for. They do say that the Devil makes work for idle hands!