Antibody response to SARS-CoV-2 vaccines among hospitalized patients in China: a case-control study.

A lack of confidence on the vaccination drive hinders the management of the COVID-19 pandemic. We aimed to assess the antibody response to the SARS-CoV-2 vaccine among hospitalized patients in China. This case-control study was based on SARS-CoV-2 sero-surveillance during hospitalization. From April to June 2021, hospitalized patients without documented COVID-19 infection from the Department of Urology were routinely assayed for anti-SARS-CoV-2 antibodies. The SARS-CoV-2 vaccination history of each participant was obtained from their vaccination records. Of the 405 participants, there were 37 seropositive participants (case group) and 368 seronegative participants (control group); 68 participants (16.8%) had received the inactivated SARS-CoV-2 vaccine, including 54 who received the Sinovac-CoronaVac vaccine and 14 received the Sinopharm vaccine. All seropositive participants who had received one or two doses of the SARS-CoV-2 vaccine were assessed for at least 16 days, while 31 (8.4%) of 368 seronegative controls who had received the vaccine were tested for 1-94 days. The overall seroconversion rate was 54.4% (37/68) in the vaccinated participants who received the inactivated SARS-CoV-2 vaccine. The odds ratio (OR) and confidence interval (CI) for seropositivity was 6.20 (95% CI: 2.05-18.71) in those received full vaccination with two doses versus those partially vaccinated participants with one dose after adjusting for sex and age. These findings imply that the inactivated SARS-CoV-2 vaccine could have a protective antibody response.

Relationship between attitudes toward the effectiveness of vaccine, concerns about adverse reactions, and proactively taking SARS-Cov-2 vaccine for family among medical workers in Taizhou, China.

OBJECTIVES: Concerns about the safety of the SARS-CoV-2 vaccine have been a stumbling block in the promotion of vaccination uptake. Although many studies have focused on the investigation of people's intention to receive the COVID-19 vaccine, little attention has been paid to the underlying mechanism. This study explored whether concerns about the adverse reactions to the vaccine mediated the relationship between attitudes toward the effectiveness of the vaccine and proactively taking the vaccine for family. METHODS: Questionnaires were completed by 1,673 (39.9%, 1673/4191) healthcare workers at Taizhou Hospital, Taizhou, Zhejiang, China. Among these, 1,397 (83.5%) have received two doses of the SARS-Cov-2 vaccine. Mediation analysis approach was applied in this research. RESULTS: Attitudes toward the effectiveness of vaccines were positively correlated with proactively taking the COVID-19 vaccine for family. Additionally, concerns about the side effects to the SARS-Cov-2 vaccine mediated the relationship between attitudes toward the effectiveness of vaccines and proactively taking vaccines for family. CONCLUSION: The findings imply inextricable relationships among attitudes toward the effectiveness of the SARS-Cov-2 vaccine, fears about side effects to vaccines, and taking vaccines for family. It further suggested that the importance of highlighting the safety of vaccine in promotion of vaccination uptake.

Sex Differences in Adverse Reactions to an Inactivated SARS-CoV-2 Vaccine Among Medical Staff in China.

Objective: We investigated whether there were sex differences in adverse reactions to an inactivated SARS-CoV-2 vaccine among medical staff in China. Methods: From 24 February to 7 March 2021 an online cross-sectional survey was conducted with a self-administered COVID-19 vaccine questionnaire among medical staff in Taizhou, China. In total, 1397 interviewees (1,107 women and 290 men) participated in the survey. Results: In our study, 178 (16.1%) women and 23 (7.9%) men reported adverse reactions following their first vaccination, and 169 (15.3%) women and 35 (12.1%) men reported adverse reactions following their second vaccination. After adjusting for confounding factors, adverse reactions to other vaccines, worry about adverse reactions, knowledge of the inactivated vaccine being used in the hospital, taking the vaccine for one's family proactively and receiving an influenza vaccination were significantly related to adverse reactions to both injections in women. In contrast, in men, concerns about adverse reactions independently increased the risk of adverse reactions following either vaccination, and a history of adverse reactions to other vaccines also increased the risk of adverse reactions to both injections. Conclusions: Sex differences in the frequency of reported adverse reactions to an inactivated SARS-CoV-2 vaccine and potential factors were demonstrated in a sample of medical staff.

Safety of an inactivated SARS-CoV-2 vaccine among healthcare workers in China.

Background: Although the inactivated SARS-CoV-2 vaccine (CoronaVac) has undergone preclinical tests and clinical trials evaluating its efficacy and safety, few data have been reported in the post-licensure real-world setting. We aimed to assess the safety of the vaccine among healthcare workers.Methods: A self-administered online survey on monitoring adverse reactions post vaccination was conducted among the staff who worked at and were vaccinated in a tertiary hospital in Taizhou, China, from February 24 to 7 March 2021. A total of 1526 subjects responded to the questionnaire when they received an e-mail or an e-poster on WeChat.Results: The incidences of overall adverse reactions after the first and second injections were 15.6% (238/1526) and 14.6% (204/1397), respectively. The most common adverse reaction was localized pain at the injection site, with an incidence of 9.6% and 10.7% after each dose, accounting for 61.8% and 73.0% of adverse reactions, respectively. Fatigue, muscle pain, and headache were the most common systemic adverse reactions.Conclusions: These findings implied that the inactivated CoronaVac vaccine has an acceptable safety profile among healthcare workers due to the low incidence of self-reported adverse reactions. This may boost public confidence in nationwide mass vaccination campaigns.