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Preclinical animal studies showed that domestic inactivated vaccine candidates induced coronavirus disease 2019 (COVID-19) specific neutralizing antibodies, raising the possibility that mass vaccination with domestic vaccines might be used in the future to end the pandemic. This research conducted a survey among the public with a WeChat mini program (an application within WeChat) to determine intention to get vaccinated. Approximately 70.48% were willing to be vaccinated. Concerns about vaccine safety and effectiveness were the most important factors influencing willingness. Older age and presence of underlying chronic disease were not shown to significantly increase public willingness. Timely and accurate scientific data are greatly needed to build public confidence in vaccines, especially among people at high risk of severe COVID-19 infection. Immunization clinics may need increased resources to ensure high vaccination coverage.
On April 16, 2020, Beijing reported the city’s first locally transmitted COVID-19 case. By April 30, 2020, Beijing reported no new cases for 14 consecutive days and lowered the COVID-19 emergency response from the highest level to the second highest level. As COVID-19 began spreading globally, Beijing faced an increasing risk of transmission of imported COVID-19 virus, also known as SARS-CoV-2. In May, 2020, domestic inactivated vaccines entered PhaseⅡclinical trials in healthy adults 18 years of age and older (1). Preclinical animal studies had shown that inactivated vaccines induced COVID-19-specific neutralizing antibodies in animals and had a protective effect with no observed antibody-dependent enhancement of infection (ADE) (2). The research conducted a survey between May 12, 2020 and May 25, 2020 to determine willingness of the general public to get a future COVID-19 vaccine.
The study was an exploratory cross-sectional survey in 2 urban districts and 3 rural districts of Beijing. Respondents were classified into 5 age groups: 18–30, 31–40, 41–50, 51–60, and >61 years old. We assumed an intention to get vaccinated (p) to be 50%, a maximum permissible error (δ) to be 10%, and an allowable α error of 5%. The estimated sample size for each age group was 385 according to the formula
$n = \left( {\dfrac{{u_\alpha ^2 \times p \times \left( {1 - p} \right)}}{{{\delta ^2}}}} \right)$ . The study surveyed at least 77 adults per age group in each district. We selected three townships with the largest population sizes. In each selected township, we selected the community with the largest population. Subjects were recruited by community committees. Two-dimensional barcodes were distributed to residential groups in WeChat, the mostly widely and frequently used mobile app for social communication in China (3). Respondents scanned the barcodes and completed the questionnaire on WeChat. The survey was brief to help ensure response quality and completeness — it took subjects only two minutes to answer all questions, decreasing the survey abandonment rate. Each mobile phone could only be used once to answer questions. The number of respondents was tallied daily. The survey ended when the number of subjects in each age group and each district reached their targets.The questionnaires were designed to obtain information on respondent willingness to be vaccinated with a future domestic COVID-19 vaccine, the most trusted sources of information, preferred vaccination venue, and demographics. Logic skip patterns and data completeness checks were set in WeChat. Study procedures were approved by the Institutional Review Board and Human Research Ethic Committee of Beijing Center for Disease Prevention and Control. Informed consent was obtained at the beginning of the survey. Intention to receive a future vaccine was the primary outcome of the survey, scored as “No”, “Uncertain”, or “Yes”. Descriptive statistics was used to summarize results. Multinomial logistic regression was used to identify factors associated with intention to receive a future vaccine. The main outcome of “Yes” (willing) was used as the referent. Statistical analyses were conducted with SPSS software (version 18.0, SPSS Inc, Chicago, IL, USA).
A total of 3,208 adults were surveyed. More than 30% of respondents were not sure that domestic COVID-19 vaccines were safe and effective. Among all respondents, 70.48% (2,261/3,208) were willing to get vaccinated, 23.66% (759/3,208) were uncertain, and 5.86% (188/3.208) were not willing to get vaccinated. Willingness varied by demographics, perception of COVID-19 disease, and vaccine characteristics. Among people aged >60 years, 74.41% were willing to get vaccination. Among people with underlying chronic disease, 73.02% were willing to get vaccinated. The 3 factors associated with the highest rate of willingness (above 80%) were belief that vaccines were safe, belief that vaccines were effective, and whether they had received influenza vaccination during the most recent 3 years. Among people who thought vaccines were unsafe or ineffective, approximately 40% were unwilling to get vaccinated (Table 1).
Variable Number of interviewees (%) Willingness to accept vaccination P value* “No”,
n (%)“Uncertain”,
n (%)“Yes”,
n (%)Gender Female 1,950 (60.79) 111 (5.70) 500 (25.64) 1,339 (68.67) 0.004 Male 1,258 (39.21) 77 (6.12) 259 (20.59) 922 (73.29) Age (years) 18–30 571 (17.80) 30 (5.25) 135 (23.64) 406 (71.10) <0.001 31–40 1,050 (32.73) 56 (5.33) 284 (27.05) 710 (67.62) 41–50 666 (20.76) 36 (5.41) 152 (22.82) 478 (71.77) 51–60 456 (14.21) 34 (7.46) 101 (22.15) 321 (70.39) >60 465 (14.50) 32 (6.88) 87 (18.71) 346 (74.41) Highest education Secondary school or lower 474 (14.78) 25 (5.27) 94 (19.83) 355 (74.89) <0.001 3-years of college 1,301 (40.55) 69 (5.30) 278 (21.37) 954 (73.33) Undergraduate or higher 1,433 (44.67) 94 (6.56) 387 (27.01) 952 (66.43) Living area Urban 1,821 (56.76) 97 (5.33) 491 (26.96) 1,233 (67.71) <0.001 Suburban 1,387 (43.24) 91 (6.56) 268 (19.32) 1,028 (74.12) Income <5,000 CNY (700 USD) 1,526 (47.57) 92 (6.03) 337 (22.08) 1,097 (71.89) 0.134 ≥5,000 CNY (700 USD) 1,682 (52.43) 96 (5.71) 422 (25.09) 1,164 (69.20) Underlying chronic disease Yes 430 (13.40) 37 (8.60) 79 (18.37) 314 (73.02) 0.002 No 2,778 (86.60) 151 (5.44) 680 (24.48) 1,947 (70.09) Seasonal flu vaccination within 3 years Yes 488 (15.21) 32 (8.44) 41 (10.82) 306 (80.74) <0.001 No 2,720 (84.79) 156 (5.51) 718 (25.38) 1,955 (69.11) Perception of seriousness of COVID-19 disease Very serious 2,227 (69.42) 117 (5.25) 494 (22.18) 1,616 (72.56) <0.001 Serious 869 (27.09) 55 (6.33) 234 (26.93) 580 (66.74) Not serious 112 (3.49) 16 (14.29) 31 (27.68) 65 (58.04) Perception of risk of contracting COVID-19 Very likely 276 (8.60) 18 (6.52) 46 (16.67) 212 (76.81) 0.020 Likely 1,467 (45.73) 73 (4.98) 355 (24.20) 1,039 (70.82) Unlikely 1,465 (45.67) 97 (6.62) 358 (24.44) 1,010 (68.94) If infected, my symptoms would be more severe than other people’s Yes 417 (13.00) 21 (5.04) 68 (16.31) 328 (78.66) <0.001 Uncertain 1,847 (57.57) 74 (4.01) 484 (26.20) 1,289 (69.79) No 944 (29.43) 93 (9.85) 207 (21.93) 644 (68.22) Perception of impact of COVID-19 pandemic on own life within the past 3 months Very serious 835 (26.03) 112 (5.56) 437 (21.68) 1,467 (72.77) <0.001 Serious 1,181 (36.81) 49 (5.08) 263 (27.28) 652 (67.63) Not serious 1,192 (37.16) 27 (11.84) 59 (25.88) 142 (62.28) Perception of impact of COVID-19 pandemic on own life in the next 6 months Very serious 390 (12.16) 86 (6.35) 295 (21.79) 973 (71.86) 0.039 Serious 964 (30.05) 69 (4.72) 357 (24.42) 1,036 (70.86) Not serious 1,854 (57.79) 33 (8.42) 107 (27.30) 252 (64.29) Perception of vaccine safety Safe 2,147 (66.93) 85 (3.96) 307 (14.30) 1,755 (81.74) <0.001 Uncertain 1,028 (32.04) 87 (8.46) 444 (43.19) 497 (48.35) Unsafe 33 (1.03) 16 (48.48) 8 (24.24) 9 (27.27) Perception of vaccine effectiveness Effective 2,189 (68.24) 87 (3.97) 314 (14.34) 1,788 (81.68) <0.001 Uncertain 1,000 (31.17) 93 (9.30) 440 (44.00) 467 (46.70) Ineffective 19 (0.59) 8 (42.11) 5 (26.32) 6 (31.58) Perception of rebound of COVID-19 infection in China Likely 632 (19.70) 63 (9.97) 121 (19.15) 448 (70.89) <0.001 Uncertain 1,596 (49.75) 73 (4.57) 448 (28.07) 1,075 (67.36) Unlikely 980 (30.55) 52 (5.31) 190 (19.39) 738 (75.31) Perception of continuity of global COVID-19 transmission Likely 1,555 (48.47) 107 (6.88) 337 (21.67) 1,111 (71.45) <0.001 Uncertain 1,195 (37.25) 50 (4.18) 327 (27.36) 818 (68.45) Unlikely 458 (14.28) 31 (6.77) 95 (20.74) 332 (72.49) *: χ2 test. Table 1. Demographic characteristics, perceptions of disease and domestic COVID-19 vaccines, and willingness to get a future vaccine in Beijing, China.
Compared with the referent (willing) group, belief that vaccines were not safe was the most strongly associated factor for vaccine hesitancy and refusal, with adjusted odds ratio (OR) values of 2.86 and 13.33, respectively. People who had chronic diseases, who thought COVID-19 infection was not serious, who thought their symptoms would be less severe than others if infected, who thought their life had not been seriously affected during the previous three months, or who thought COVID-19 was likely to rebound in China, were more likely to refuse vaccines. Being uncertain of vaccine effectiveness was the second most associated factor for vaccine hesitancy, with an adjusted OR value of 2.68 (Table 2).
Variable Unwillingness* Uncertainty* Unadjusted OR (95%CI) Adjusted OR (95%CI) Unadjusted OR (95%CI) Adjusted OR (95%CI) Gender Female 1 1 1 1 Male 1.01 (0.74–1.36) 0.91 (0.65–1.26) 0.75 (0.63–0.89) 0.88 (0.72–1.06) Age (years) 18–30 1 −† 1 −† 31–40 1.07 (0.67–1.69) −† 1.20 (0.95–1.53) −† 41–50 1.02 (0.62–1.68) −† 0.96 (0.73–1.25) −† 51–60 1.43 (0.86–2.39) −† 0.95 (0.70–1.27) −† >60 1.25 (0.75–2.10) −† 1.20 (0.95–1.53) −† Highest education Secondary school or lower 1 1 1 1 3-years of college 1.03 (0.64–1.65) 1.54 (0.92–2.59) 1.10 (0.85–1.43) 1.06 (0.79–1.43) Undergraduate or higher 1.40 (0.89–2.22) 1.26 (0.75–2.13) 1.54 (1.19–1.98) 1.39 (1.03–1.86) Living area Urban 1 1 1 1 Suburban 1.13 (0.84–1.52) 1.28 (0.92–1.79) 0.66 (0.55–0.78) 0.79 (0.65–0.96) Income <5,000 CNY (700 USD) 1 1 1 1 ≥5,000 CNY (700 USD) 0.98 (0.73–1.32) −† 1.18 (1.00–1.39) −† Underlying chronic disease Yes 1 1 1 1 No 0.66 (0.45–0.96) 0.50 (0.32–0.78) 1.39 (1.07–1.80) 1.17 (0.86–1.58) Seasonal flu vaccination within 3 years Yes 1 1 1 1 No 0.76 (0.51–1.14) 0.69 (0.44–1.07) 2.74 (1.96–3.84) 2.28 (1.59–3.27) Perception of seriousness of COVID-19 disease Very serious 1 1 1 1 Serious 1.31 (0.94–1.83) 1.25 (0.88–1.79) 1.32 (1.10–1.58) 1.33 (1.08–1.63) Not serious 3.40 (1.91–6.06) 2.27 (1.18–4.37) 1.56 (1.01–2.42) 1.39 (0.86–2.27) Perception of risk in contracting COVID-19 Very likely 1 1 1 1 Likely 0.83 (0.48–1.42) 0.86 (0.48–1.56) 1.58 (1.12–2.21) 1.17 (0.80–1.70) Unlikely 1.13 (0.67–1.91) 1.12 (0.61–2.07) 1.63 (1.16–2.30) 1.31 (0.89–1.93) If infected, my symptoms would be more severe than other people’s Yes 1 1 1 1 Uncertain 0.90 (0.54–1.48) 1.22 (0.70–2.12) 1.81 (1.37–2.40) 1.38 (1.01–1.91) No 2.26 (1.38–3.69) 3.05 (1.71–5.45) 1.55 (1.14–2.10) 1.23 (0.86–1.76) Perception of impact of COVID-19 pandemic on own life within the past 3 months Very serious 1 1 1 1 Serious 0.98 (0.70–1.39) 1.16 (0.75–1.80) 1.35 (1.13–1.62) 1.28 (1.01–1.61) not serious 2.49 (1.58–3.92) 2.54 (1.35–4.78) 1.40 (1.01–1.92) 1.17 (0.77–1.78) Perception of impact of COVID-19 pandemic on own life in the next 6 months Very serious 1 1 1 1 Serious 0.75 (0.54–1.05) 0.77 (0.51–1.16) 1.14 (0.95–1.36) 1.07 (0.85–1.34) Not serious 1.48 (0.97–2.27) 1.06 (0.58–1.95) 1.40 (1.08–1.82) 1.39 (0.97–1.97) Perception of vaccine safety Safe 1 1 1 1 Uncertain 3.61 (2.64–4.95) 2.35 (1.44–3.83) 5.11 (4.28–6.09) 2.50 (1.91–3.27) Unsafe 36.71 (15.77–85.47) 13.33 (4.83–36.80) 5.08 (1.95–13.27) 2.86 (1.02–7.96) Perception of vaccine effectiveness Effective 1 1 1 1 Uncertain 4.09 (3.00–5.58) 2.52 (1.55–4.10) 5.37 (4.50–6.40) 2.68 (2.05–3.50) Ineffective 27.40 (9.30–80.73) 3.52 (0.94–13.17) 4.75 (1.44–15.64) 3.28 (0.92–11.77) Perception of rebound of COVID-19 infection in China Likely 1 1 1 1 Uncertain 0.48 (0.34–0.69) 0.57 (0.37–0.89) 1.54 (1.23–1.94) 1.23 (0.93–1.62) Unlikely 0.50 (0.34–0.74) 0.56 (0.35–0.92) 0.95 (0.74–1.23) 1.08 (0.79–1.48) Perception of continuity of global COVID-19 transmission Likely 1 1 1 1 Uncertain 0.64 (0.45–0.90) 0.63 (0.41–0.97) 1.32 (1.10–1.57) 0.96 (0.77–1.20) Unlikely 0.97 (0.64–1.47) 1.16 (0.70–1.92) 0.94 (0.73–1.22) 1.12 (0.83–1.52) *: Being willing to get vaccine was selected as reference category in multinomial logistic regression.
†: Variables that were not statistically significant in univariate analyses were excluded from the multinomial logistic regression model.Table 2. Factors associated with intention to get a future domestic COVID-19 vaccine in Beijing, China.
Respondents’ most popular sources of information about COVID-19 vaccines were social media (86.94%, 2,789/3,208), medical doctors (78.68%, 2,524/3,208), and professional papers (34.57%, 1,109/3,208). Among the 2,261 respondents who were willing to get vaccinated, 58.29% (1,318/2,261) preferred getting vaccinated in immunization clinics.
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