Although previous studies have shown that vaccinated people with inactivated virus-based vaccines do not show measurable anti-N Abs in their sera [22], it could be speculated that the inactivated virus in the Sinopharm vaccine normally elicits a weak and undetectable anti-N Ab response that was boosted by a current natural infection or that the vaccine itself serves as a booster to a previous mild or asymptomatic infection. Here, DDX41 is linked to infection.