The president and chief executive of the International AIDS Vaccine Initiative, Seth Berkley, wrote an opinion piece in the October 19 New York Times in which he criticizes those who cast doubt on recent HIV vaccine successes.

Last month, researchers revealed that a two-part HIV vaccine tested on more than 16,000 volunteers in Thailand reduced the risk of infection by more than 30 percent. However, just a few days later, researchers were briefed privately about a second type of analysis that showed the vaccine regimen, known as RV 144, to be less effective than originally reported, which fueled skepticism from researchers and media outlets. The second analysis also showed that chance—rather than the protective effect of RV 144—might have been the reason why fewer volunteers in the vaccinated group contracted HIV compared with the placebo group.

In the Times piece, Berkley writes that doubting the possibility of an HIV vaccine “would be a shame.”

He adds, “This illustrates why the controversy over statistical significance is exaggerated. Whether you consider the first or second analysis, the observed effect of the Thai candidates was either just above or below the level of statistical significance. Statisticians will tell you it is possible to observe an effect and have reason to think it’s real even if it’s not statistically significant. And if you think it’s real, you ought to examine it carefully.”