The pandemic brought a massive effort to limit the spread of bad health information. Did it do more harm than good?
In March 2021, a Twitter user asked Martin Kulldorff if everyone needed to be vaccinated against COVID-19. Kulldorff, then a professor at Harvard Medical School, had spent 20 years researching infectious diseases and contributing to the development of the country’s vaccine safety surveillance system.
“No,” he responded. The vaccines were important for some high-risk people, he wrote, but “those with prior natural infection do not need it. Nor children.”
That advice put Kulldorf outside the mainstream in his field, and he soon faced consequences from Twitter (now known as X). The social network labeled the tweet as misleading and inserted a link offering users an opportunity “to learn why health officials recommend a vaccine for most people.” Twitter also limited the post’s ability to be retweeted and liked, Kulldorff said in a recent interview.