In 2013, the New Scientist reported that "part of a surface protein on the pandemic virus looks very similar to part of a brain protein that helps keep people awake".[28] However, the original scientific article claiming that HA protein in both the virus and the vaccine could, in some people, trigger an immune reaction against hypocretin, was recently retracted because the data could not be reproduced.[29] However, further investigations indicated that "antibodies to influenza nucleoprotein cross-react with human hypocretin receptor 2".[30]