Waffling. As data change, we should expect public health advice to evolve (slowly) over time; this is the nature of science. What is unacceptable is waffling, that is, giving one answer one day and a completely different answer another day. The WHO did that when it announced that asymptomatic carriers only rarely transmitted coronavirus infections, only to retract the statement 24 hours later.
Moving the goalposts. At the beginning of the pandemic, public health officials urged the need to “flatten the curve,” the goal of which is to prevent a spike in infections that overwhelms healthcare systems. This is an achievable and necessary goal.
Over time, however, “flatten the curve” took on a new meaning. Instead of slowing the spread of the disease – to decrease the burden on overloaded hospitals and buy time for the development of drugs or vaccines – the goal became to stop disease transmission entirely. This is a ludicrous goal because – like stopping the spread of the common cold or influenza – it is nearly impossible. Similarly, “finding a cure” became a common refrain, despite the fact that there may never be a good vaccine or antiviral for coronavirus.