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.

While controversy continues over predatory journals, there are various opinions regarding the effectiveness of the whitelist and blacklist. In this regard, it is an important research question to investigate the impact of the Chinese Academy of Sciences' early warning list, which was disclosed in 2020. This study examined how the number of papers in 65 journals included in the 2020 list changed by country/year. The result shows that China's number of papers sharply declined in 2021 and then increased again in 2022. When examining individual journals, it was found that the effects of early warning list were very diverse. As long as the quantitative evaluation system continues in some Asian countries, this study suggests that simply whitelist/blacklist policies will have little influence on the academic ecosystem.