Impact Factor polarization during the COVID-19 pandemic

The COVID-19-related research field has emerged with a number of papers and citations in a very short time period. Journals published COVID-19-related works have increased their impact factor (IF), which reflects the attention on COVID-19. With publications of COVID-19-related works in Web of Science, we found that COVID-19-related papers increased IF of journals but more benefits were given to the high IF journals. Highly cited COVID-19-related papers were distributed in high IF journals. This increases the inequality of IF in research category. In conclusion, our findings imply that IF is vulnerable to external events, therefore it supports to warn the use of quantitative indicators in assessment.