A few that come to mind:
1. Public health agencies originally stated that N95 respirators don’t work and require special fit training. This guidance vanished the moment respirators stopped being in short supply.
2. The public was repeatedly told the virus was not thought to be transmissible by airborne particles, even though there was evidence that it was. Similarly, well after fomite transmission had been ruled out, health agencies continued to preach hand-washing and surface disinfection.
3. Concerns that the vaccines might have serious side effects were blasted as anti-science lunacy. Later, the vaccines were proved to cause serious side effects in some people.
4. Any discussion of the lab leak theory was treated as radioactive.
I could go on.
What’s bothersome about these examples isn’t that the science was imperfect or evolving. It’s that the public were lied to, and were also told they should not dare question Science (with a capital S). When I read that scientific journals censor entire avenues of inquiry because the implications are undesirable, I wonder if real science even exists in politically sensitive fields.