Background The COVID-19 outbreak has induced negative emotions among people. These emotions are expressed by the public on social media and are rapidly spread across the internet, which could cause high levels of panic among the public. Understanding the changes in public sentiment on social media during the pandemic can provide valuable information for developing appropriate policies to reduce the negative impact of the pandemic on the public. Previous studies have consistently shown that the COVID-19 outbreak has had a devastating negative impact on public sentiment. However, it remains unclear whether there has been a variation in the public sentiment during the recovery phase of the pandemic. Objective In this study, we aim to determine the impact of the COVID-19 pandemic in mainland China by continuously tracking public sentiment on social media throughout 2020. Methods We collected 64,723,242 posts from Sina Weibo, China’s largest social media platform, and conducted a sentiment analysis based on natural language processing to analyze the emotions reflected in these posts. Results We found that the COVID-19 pandemic not only affected public sentiment on social media during the initial outbreak but also induced long-term negative effects even in the recovery period. These long-term negative effects were no longer correlated with the number of new confirmed COVID-19 cases both locally and nationwide during the recovery period, and they were not attributed to the postpandemic economic recession. Conclusions The COVID-19 pandemic induced long-term negative effects on public sentiment in mainland China even as the country recovered from the pandemic. Our study findings remind public health and government administrators of the need to pay attention to public mental health even once the pandemic has concluded.

Covid-19 has impacted people’s lives significantly, and it might continue to impact them until people find a way to deal with it indefinitely. In the early stage of the pandemic, when there was no vaccine and COVID-19 had an outbreak, the government decided to implement a lockdown policy to stop the spread. Several questions have arisen, whether lockdown affects intimate partner violence and how it will change after lockdown. This study examined intimate partner violence experienced by people during the COVID-19 lockdowns in Los Angeles. By selecting intimate partner violence data from 2019 to 2022 from Los Angeles crime dataset and using Difference-in-Difference method compare the intimate partner crime counts during different period, the following result is generated. The study shows that intimate partner violence will drop significantly at the beginning of the lockdown and increase as lockdown time increases. Intimate partner violence also increases when the lockdown is over. This study could be used for future policy making and preventing intimate partner violence in case another pandemic outbreak requires lockdown.

BACKGROUND As the outbreak of COVID-19 has caused a wide range of panic in the general public, it is essential to understand how online public sentiments change during the pandemic given its importance for mental health policy. OBJECTIVE Previous studies consistently showed a devastating negative impact of COVID-19 on public sentiments after the outbreak. However, it remains unclear the variation of public sentiment during the recovery phase of the pandemic. METHODS In the current study, we continuously tracked online public sentiment through the year 2020 by analyzing emotion reflected on 64,723,242 posts across China’s largest social media platform Sina Weibo. RESULTS We found that the pandemic not only affected online public sentiment in the initial outbreak but also induced long-term negative effects even in the aftermath of the successful recovery from the pandemic. The long-term negative effect was not due to the pandemic’s severity either locally or globally, or even the post-pandemic economic recession. CONCLUSIONS COVID-19 induces long-term negative effects on public sentiments even in the aftermath of the successful recovery from the pandemic. It reminds public health and government administrators of the need to pay heed to public mental health even once the pandemic has concluded.