Francois Balloux:

A common misunderstanding is that “the science” is a set of absolute, immutable, indisputable and verifiable facts. Rather, science is a messy process eventually converging towards the truth in a process of trial and error.

Many scientific publications are false – because they relied on inadequate data or analyses, but more often the results are just false-positives, picking up a statistically significant association when they shouldn’t. Indeed, each time a statistical test is performed, there is a small chance it will pick up a pattern even when there is none. Such false-positive findings are particularly likely to arise in studies with small sample sizes, as those are inherently noisier.

The problem is made worse because studies reporting positive findings are more likely to be written up and publicised. (Those failing to detect a statistically significant effect often tend to remain unpublished.) Publications reporting false-positive results are also more common among the first studies, a pattern known as the “winner’s curse”.

There have been several instances during the pandemic where the first studies pointed to results that could not be replicated by other, often larger, studies. One example was the anti-parasite drug ivermectin. Several early studies on a small number of patients reported promising results, which led many to believe that it was a miracle cure for Covid-19. It was only once data from large clinical trials became available that ivermectin could be confidently ruled out as a useful drug against the virus.

More recently, a preprint reported that current Omicron lineages in circulation (BA.1.12, BA.4 and BA.5) may have reverted to a level of virulence comparable to the previous Delta variant, mostly on the basis of experimental infections in hamsters. Those early results caused considerable alarm but could not be replicated in other hamster experiments. They were also at variance with the massive body of real-world evidence from many countries showing no increase in hospitalisation or death rates for infections caused by current strains in circulation.

Of the myriad doomsday Covid-19 variants that have been anticipated on the basis of early and often poor evidence, few did in fact sweep the world. Though some did: the Alpha and Delta variants were both more transmissible and associated with higher hospitalisation and death rates than any lineage in circulation before them. And the Omicron variant spread globally very rapidly, mainly because it could largely bypass existing population immunity conferred by vaccines and prior infections, but luckily, its severity lies well below that of the early pandemic lineages and any subsequent variant.

I remember chuckling a bit when politicians would confidently state that they were/are “following the science”.….

Ethan Ennals:

Infectious diseases expert and former presidential Covid adviser Dr Deborah Birx told The Mail on Sunday that coronavirus ‘came out of the box ready to infect’ when it emerged in the Chinese city of Wuhan in December 2020. 

The adviser said most viruses take months or years to become highly infectious to humans. But, Dr Birx said, Covid ‘was already more infectious than flu when it first arrived’.

She said that meant Covid was either an ‘abnormal thing of nature’ or that Chinese scientists were ‘working on coronavirus vaccines’ and became infected.

‘It happens, labs aren’t perfect, people aren’t perfect, we make mistakes and there can be contamination,’ she said.