Differences in incidence and fatality of COVID-19 by SARS-CoV-2 Omicron variant versus Delta variant in relation to vaccine coverage: A world-wide review.

We aim to evaluate the evolution differences in the incidence and case fatality rate (CFR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta and Omicron variants. The average incidence and CFRs were described between different countries. A gamma generalized linear mixed model (GLMM) was used to compare the CFRs of Delta and Omicron variants based on vaccination coverage. Totally, 50 countries were included for analyses. The incidence of coronavirus disease 2019 (COVID-19) ranged from 0.16/100,000 to 82.95/100,000 during the Delta period and 0.03/100,000 to 440.88/100,000 during the Omicron period. The median CFRs were 8.56 (interquartile range [IQR]: 4.76-18.39) during the Delta period and 3.04 (IQR: 1.87-7.48) during the Omicron period, respectively. A total of 47 out of 50 countries showed decreased CFRs of the Omicron variant with the rate ratio ranging from 0.02 (95% confidence interval [CI]: 0.01-0.03) (in Cambodia) to 0.97 (95% CI: 0.87-1.08) (in Ireland). Gamma GLMM analysis showed that the decreased CFR was largely a result of the decreased pathogenicity of Omicron besides the increased vaccination coverage. The Omicron variant shows a higher incidence but a lower CFR around the world as a whole, which is mainly a result of the decreased pathogenicity by SARS-CoV-2's mutation, while the vaccination against SARS-CoV-2 still acts as a valuable measure in preventing people from death.

Change in willingness to COVID-19 vaccination in China: Two online surveys during the pandemic.

OBJECTIVE: As the variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, periodic vaccine booster immunization may become a normal policy. This study investigated the changes and factors associated with vaccination intentions in various epidemic situations, which can provide suggestions for the construction and modification of routine vaccination program strategies. METHODS: Two cross-sectional online surveys were conducted in January and June of 2021. The willingness and confidence of the coronavirus disease 2019 (COVID-19) vaccination were measured following propensity score matching (PSM) treatment. The difference in the willingness for COVID-19 Vaccination in the two surveys was analyzed by single or multi-factor analyses. RESULTS: The willingness to accept the SARS-CoV-2 vaccine was higher in the second survey than that in the first survey (90.5% vs. 66.6%, p < 0.001). Concerns about the vaccine's safety declined (71.0% vs. 47.6%, p < 0.001), but concerns about the efficacy increased (22.4% vs. 30.9%, p < 0.001). Confidence in the SARS-CoV-2 vaccine had an important impact on the increased uptake willingness (odds ratio = 3.19, 95% confidence interval: 2.23-4.58, p < 0.001). CONCLUSIONS: There has been a significant increase in attitudes towards the SARS-CoV-2 vaccine which was associated with higher vaccine confidence. Vaccine effectiveness received more concerns from respondents rather than safety after nearly 6 months' utilization of the SARS-CoV-2 vaccine. It indicates that aggressive communication and timely disclosure of vaccine data can build vaccine confidence.

Willingness and SARS-CoV-2 Vaccination Coverage among Healthcare Workers in China: A Nationwide Study.

Background: The SARS-CoV-2 vaccine has been widely rolled out globally in the general populations. However, specific data on vaccination confidence, willingness or coverage among health care workers (HCWs) has been less reported. Methods: A cross-sectional online survey was conducted to specify the basic data and patterns of vaccination confidence, willingness and coverage among HCWs nationwide. Results: In total, 2386 out of 2583 (92.4%) participants were enrolled for analysis, and the rates of confidence in vaccine, professional institutes and government were 75.1%, 85.2% and 85.4%, respectively. The overall vaccination coverage rate was 63.6% which was adjusted as 82.8% for participants under current medical conditions or having contraindications. Confidence in vaccine safety was shown to be the most related factor to willingness among doctors, nurses, medical technicians and hospital administrators, while confidence in vaccine effectiveness as well as trust in government played the key role in formulating public health employees' willingness. 130 (7.1% of 1833) participants reporting willingness still not been vaccinated regardless of contraindications. Multivariate analysis among willingness participants showed that males, aged over 30 years, public health employees and higher vaccination confidence had significantly higher vaccination rates with ORs (95% confidence intervals) as 1.64 (1.08-2.49), 3.14 (2.14-4.62), 2.43 (1.46-4.04) or 2.31 (1.24-4.33). Conclusions: HCWs' confidence, willingness and coverage rates to the vaccine were generally at high levels. Heterogeneity among HCWs should be considered for future vaccination promotion strategies. The population's confidence in vaccination is not only the determinant to their willingness, but also guarantees their actual vaccine uptake.

Vaccination willingness, vaccine hesitancy, and estimated coverage at the first round of COVID-19 vaccination in China: A national cross-sectional study.

BACKGROUND: Vaccination against coronavirus disease 2019 (COVID-19) has become an important public health solution. To date, there has been a lack of data on COVID-19 vaccination willingness, vaccine hesitancy, and vaccination coverage in China since the vaccine has become available. METHODS: We designed and implemented a cross-sectional, population-based online survey to evaluate the willingness, hesitancy, and coverage of the COVID-19 vaccine among the Chinese population. 8742 valid samples were recruited and classified as the vaccine-priority group (n = 3902; 44.6%) and the non-priority group (n = 4840; 55.4%). RESULTS: The proportion of people's trust in the vaccine, delivery system, and government were 69.0%, 78.0% and 81.3%, respectively. 67.1% of the participants were reportedly willing to accept the COVID-19 vaccination, while 9.0% refused it. 834 (35.5%) reported vaccine hesitancy, including acceptors with doubts (48.8%), refusers (39.4%), and delayers (11.8%). The current coverage was 34.4%, far from reaching the requirements of herd immunity. The predicted rate of COVID-19 vaccination was 64.9%, 68.9% and 81.1% based on the rates of vaccine hesitancy, willingness, and refusal, respectively. CONCLUSIONS: The COVID-19 vaccine rate is far from reaching the requirements of herd immunity, which will require more flexible and comprehensive efforts to improve the population's confidence and willingness to vaccinate. It should be highlighted that vaccination alone is insufficient to stop the pandemic; further efforts are needed not only to increase vaccination coverage but also to maintain non-specific prevention strategies.