I once heard of a pediatrician who successfully convinced a concerned mother that anti-vax ideology was likely a psyop by the Russians to weaken the health of the American populace starting with our children. Doesn't hurt that it's probably true.

EDIT: My personal conspiracy theory is that the Chinese government did engineer (or at least selectively cultivate) COVID, but not to kill Americans. In the early days of the pandemic there was some speculation that it affected some blood types more than others, particularly type A. While no link to blood type specifically was found, type A is a more common genetic trait as you move out of Asia and towards the middle east. China has been heavily persecuting the Uyghurs (Chinese Muslims), and those who have managed to get out of the camps have reported medical experimentation and being injected with unknown substances. In addition, the virus would also kill a significant number of the older population, which is important because of the population crunch they're about to experience due to one-child policies resulting in a high amount of female-specific infanticide. They're about to have a bunch of old people and a massive shortage of able bodied young people to care for them. Even if they didn't directly "engineer" the virus in a gene-sequencing manner, they have a lot off motive to just generally cultivate and spread (you can't really "breed" a virus) an infectious disease targeting people of middle eastern descent and elders.

Thank you for coming to my tinfoil-hat Ted Talk.