Assessing Determinants of COVID- 19 Vaccine Hesitancy in Nevada

Abstract

In December 2020, we conducted a telephone survey to determine what factors are connected to COVID-19 vaccine hesitancy among adults in Nevada. The survey was based on factors identified in other studies, such as demographic variables (age, race, ethnicity, gender, household income, urbanicity, educational attainment), health status, previous COVID-19 infections, social media engagement, adherence to social distancing guidelines, beliefs about COVID-19, and political ideology identifications. Using a proportional odds model, we compared vaccine hesitancy levels to determine the odds of being more likely versus unlikely to get the COVID-19 vaccine. Of 1,000 people surveyed, 30.4% exhibited vaccine hesitancy. Findings showed that adults with significantly lower odds of vaccine hesitancy included those who were male, older, worried about COVID-19 infection or its community effects, adhered to social distancing, and reported higher incomes. Adults who identified as African American or Black or as multiple or “other” races exhibited significantly higher odds of vaccine hesitancy than White adults. Adults self-identifying as conservative had significantly higher odds of vaccine hesitancy than others. Vaccine hesitancy levels suggest possible hurdles to addressing the COVID-19 pandemic in a state with high visitor volumes and demographics that resemble the country's future as minority White, highlighting possible lessons for future pandemics. Most measures of COVID-19 worry were not significantly associated with vaccine hesitancy, suggesting that vaccination efforts should focus on other motivators. COVID-19 vaccination efforts should also directly encourage uptake by younger and middle-aged adults who are female, African American, have lower incomes, and identify as conservative.

Introduction

The COVID-19 pandemic has brought unimaginable challenges. The United States alone has seen over 47.6 million confirmed cases of COVID-19, with over 770,890 deaths as of late November 2021.¹ Estimates suggest the actual number of cases may be over 146 million, with resulting hospitalizations at 7.5 million.² In addition, the long-term implications of COVID-19 are only beginning to be understood,^3,4 but appear to include symptoms such as severe shortness of breath, fatigue, and muscle pain and impact the respiratory, enteric, musculoskeletal, and neurological systems.³ Further, the number of US adults reporting depressive disorder or anxiety symptoms have remained significantly higher than before the pandemic; 11% reported anxiety or depressive disorder symptoms in the first half of 2019,⁵ with levels peaking at 42.6% in November 2020, and then appearing to slowly trend downward until July 2021.⁶ However, the most recently available data show a slight increase in October 2021 to 31.6%, still well above prepandemic levels.^5,6

Some US communities bear a disproportionate share of these COVID-19 health burdens. For instance, COVID-19 deaths among African American/Black, Alaskan Native or American Indian, and Hispanic/Latino groups are higher than their population shares.⁷ Hospitalization rates, accounting for age, also vary across race and ethnicity; one dataset indicates that between March 2020 and July 2021, for every 100,000 people in each group, 1,037.3 Hispanic, 1,271.2 non-Hispanic American Indian or Alaskan Native, and 1,043.3 non-Hispanic African American/Black people were hospitalized due to COVID-19, compared with 357.0 non-Hispanic Asian or Pacific Islander and 373.8 non-Hispanic White people.⁸ Other important health disparities also exist. For example, younger adults, those with income loss, and essential workers have been especially likely to report anxiety and depression symptoms during the pandemic.⁵

It is difficult to overstate the impact of COVID-19 on social factors, many of which overlap with social determinants of health. Feeding America suggests about 42 million Americans will be food insecure in 2021, compared with 35.2 million in 2019.⁹ This pandemic has led to unprecedented job loss, especially in sectors such as leisure and hospitality, retail, arts, education, and healthcare; while some jobs have recovered, it is unclear how long a full recovery will take.¹⁰ As pandemic closures and layoffs took root in 2020, the US unemployment rate reached 14.7%—an all-time high in Bureau of Labor Statistics data.¹¹ In Nevada, the seasonally adjusted unemployment rate rose above 28%¹² following a temporary shutdown of nonessential businesses. That rate fell to 7.7% by July 2021, still the highest in the nation and more than twice the February 2020 rate.^12,13 The economic effects of stay-at-home orders and business shutdowns also caused a drastic decline in the 2020 second-quarter US real gross domestic product, although the rate rebounded in the third quarter.^14,15

Over a year and a half since the pandemic began, the United States continues its COVID-19 response. Individual behaviors such as washing hands, covering coughs and sneezes, and physical distancing remain important for preventing transmission.¹⁶ Community-level, policy-based mitigation measures, such as requirements to wear face masks and to limit in-person restaurant dining, were also linked to improved COVID-19 incidence rates and hospitalization, case, and death growth rates.^17-19 Amid lowered positivity rates and increasing vaccination rates nationwide, mask mandates and social distancing requirements were initially loosened across the country, including in Nevada in May 2021. However, a surge in cases and hospitalizations, as well as evidence of heightened transmissibility of the Delta variant when compared with other variants, resulted in guidance from the US Centers for Disease Control and Prevention in July 2021 calling for renewed indoor masking in areas with substantial or high transmission.²⁰

Long-lasting interventions in the form of vaccines against COVID-19 are now readily available in the United States to those over the age of 5 years. They are critical to ending this pandemic.²¹ To date, the US Food and Drug Administration has granted emergency use authorization or full approval of the Pfizer-BioNTech, Moderna, and Johnson & Johnson Janssen COVID-19 vaccines.²² As of November 22, 2021, over 230 million people in the United States, or 69.5%, have received at least 1 dose, 59.2% are fully vaccinated, and 18.4% have received booster shots.²³ Yet data reveal differences in vaccination rates by geography, sex, race, ethnicity, age, and other factors.²⁴ At the start of the vaccination effort, unpacking these differences was difficult due to data limitations and demographics of vaccine priority groups, such as healthcare workers. Despite the speed at which COVID-19 vaccines have been developed and deployed, practical challenges accompany the vaccination efforts, including effective and fair distribution and delivery, tracking who is and is not vaccinated, spurring demand, and creating global availability.²¹

Vaccine hesitancy also presents an enormous challenge to a vaccination-based strategy to address COVID-19. The Strategic Advisory Group of Experts (SAGE) Working Group on Vaccine Hesitancy concluded that vaccine hesitancy refers to “delay in acceptance or refusal of vaccination despite availability of vaccination services. Vaccine hesitancy is complex and context specific, varying across time, place and vaccines. It is influenced by factors such as complacency, convenience and confidence.”²⁵ A Kaiser Family Foundation US-based survey in July 2021 found that 14% of those polled would “definitely not” take a free, US Food and Drug Administration-approved vaccine, 3% would get it “only if required,” and 10% planned to “wait and see.” Twenty percent of unvaccinated adults said they were more likely to get vaccinated due to news of the variants.²⁶ Separate survey data suggest vaccine hesitancy rates declined steadily from late 2020 to March 2021.²⁷

Certain groups have comparatively higher hesitancy and lower vaccination intent, including adults who are non-Hispanic Black, female, and younger, and adults who lack health insurance, live in rural areas, and have lower educational attainment and income.^26,28,29 Khubchandani et al³⁰ suggested that education, income, employment, children at home, political affiliation, and perceived threat of infections all predict vaccine hesitancy. Similarly, Latkin et al³¹ found that adults who were female, younger, Black, Hispanic, and those who identified as more conservative were significantly less likely to articulate an intention to receive a vaccine. Guidry et al³² found that concerns about needles, limited vaccine supply, and fast vaccine development predicted reduced intent to receive COVID-19 vaccines closer to the start of the rollout; meanwhile, more worries about vaccine side effects and vaccine apathy predicted reduced intent to receive any COVID-19 vaccine, while more worries about adverse reactions also predicted reduced intent to receive a vaccine specifically authorized for emergency use. They suggest that misinformation, including through social media, and the speed of vaccine development, approval for emergency use, and administration may play a role in COVID-19 vaccine hesitancy.³²

The US rollout of the COVID-19 vaccine has varied by state. Nevada initially primarily followed the Advisory Committee on Immunization Practices guidelines, prioritizing groups based on length and level of exposure, job specialties, risk of spread, morbidity, and mortality.³³ As of November 22, 2021 in Nevada, 61.0% of the population aged 5 years and older had initiated vaccination (meaning had as least 1 dose), and 52.1% were fully vaccinated.³⁴

Understanding vaccine uptake and hesitancy in Nevada is important for several reasons and may have a significant impact on informing strategies to increase national vaccination rates. Nevada is a good case study for vaccine hesitancy because its population is diverse and, in many important ways, resembles the current US population. For example, the state population of people aged 65 years and older (16.7%) and the high school graduation rate (86.8%) is similar to that of the United States as a whole (16.5% and 88.0%, respectively).^35,36 Nevada also has 2 metropolitan areas (Las Vegas and Reno), whereas the rest of the state is rural and frontier,³⁷ resulting in a population that lives in different environments and resembles the makeup of the United States. Nevada's population is also diverse in political affiliation; recent tracking by Gallup suggests that Nevada is 1 of only 15 states that is politically competitive, as opposed to solidly Democratic or Republican.³⁸ Because we know that age, educational attainment, geographic distribution, and political affiliation may all be relevant factors in perceptions around COVID-19 and vaccination,^28,30,31 understanding vaccine hesitancy in Nevada can inform continuing COVID-19 vaccination efforts across the country. Nevada has also been a US COVID-19 hotspot, with lower vaccination rates than much of the country and higher infection rates, hospitalization rates, and deaths.³⁹ Nevada is also a domestic and international travel hub—meaning that exposure of travelers who come to Nevada and return to other undervaccinated communities in the United States and abroad could exacerbate the spread of infections. Las Vegas alone typically hosts over 40 million visitors annually.⁴⁰

Findings from Nevada's experience could provide a glimpse into the future of the United States. Nevada's racial, ethnic, and immigrant-status demographics—that is, lower numbers of White and non-Hispanic populations and higher numbers of immigrant populations—resemble US demographic projections. Nevada is a majority–minority state, meaning that the non-Hispanic White population does not make up the state's majority.³⁶ The United States as a whole is estimated to become “minority White” by 2045.⁴¹ Furthermore, Nevada has a larger immigrant population (19.4%) compared with the nation (13.6%).³⁶ The percentage of foreign-born persons for the whole nation will reach 17.1% by 2060.⁴¹ For this reason, Nevada today represents the future of US demographics, and the determinants of vaccine hesitancy in Nevada could provide insights into efficient and effective means to target vaccination strategies as the COVID-19 pandemic continues and when future pandemics take hold. All of these factors make understanding COVID-19 vaccine hesitancy in Nevada potentially important as we continue to deal with COVID-19 and gear up for future pandemics. Therefore, this study aimed to answer the question, “What are the determinants of COVID-19 vaccine hesitancy in Nevadan adults?”

Methods

Data Collection

We used a cross-sectional design to collect survey data from adults in Nevada aged 18 years and older. Data were collected by a market research firm via landline telephone (n = 408) and cell phone (n = 592) across the state of Nevada, with a response rate of 29.97%. Calls were made on all days of the week between 5 pm and 9 pm local time. All data were collected from December 21 to 28, 2020, just after the first 2 COVID-19 vaccines received emergency use authorization. A total of 1,000 people responded to the survey. All data remained anonymous, and the University of Nevada, Las Vegas Office of Research Integrity determined this protocol to be exempt from full review.

Setting

Located in the southwestern United States, Nevada is considered an intermountain western state, with has an estimated population of 3.1 million.³⁵ As stated earlier, Nevada is a majority–minority state with a larger immigrant population than the nation as a whole,³⁶ and it reflects the overall demographics and social characteristics of the United States. Politically, Nevada is considered a “swing state,” with democratic presidential candidates carrying the state for the last 4 presidential elections.^42,43 Some of the key industries in Nevada include tourism and gaming, mining, manufacturing and logistics, and natural resource technologies.⁴⁴ Some of the major drivers of the state's gross domestic product include accommodations and food services (which includes tourism and gaming), retail, healthcare and social assistance, construction, natural resources and mining.⁴⁵

Questionnaire

We created a questionnaire to understand the determinants of COVID-19 vaccine hesitancy based on previously identified vaccine hesitancy factors,^46-49 including demographic variables of age, gender, race and ethnicity, educational attainment, and median household income. We also asked about general health status, previous COVID-19 infection, and use of social media to learn about neighborhood happenings and events or to connect with community members. Adherence to government social distancing guidelines and belief about COVID-19 posing a large risk to the community were measured on a 4-point Likert scale ranging from “strongly agree” to “strongly disagree.”⁴⁸ Perceived threat was measured on a 3-point scale by asking respondents to indicate their level of worry—“very worried,” “somewhat worried,” or “not worried at all”—about a loved one becoming infected, severely ill, or dying from COVID-19. COVID-19-related anxiety was measured by their current level of worry (modified from Rothgerber et al⁴⁸). Conservatism and liberalism were measured on a 4-point scale by indicating their level of agreement with the following statement: “I generally take the conservative/liberal view on most issues.” Respondents were categorized into urban or rural/frontier based on their US Census Bureau's county classification.⁵⁰ The dependent variable of vaccine hesitancy was measured using a 4-point Likert scale ranging from “very likely” to “very unlikely” in response to the following question: “If a COVID-19 vaccine is available to you in the next 6 months, how likely are you to get it?” The internal consistency reliability of the scale consisting of attitudinal items was determined using Cronbach alpha, which was found to be 0.74 and thus acceptable.⁵¹ Previous studies have used similar questions and scales to measure vaccine hesitancy. ^{28,30,47,49,52}

Statistical Analysis

We first conducted demographic analyses to present the data profile from the 1,000 samples. Then, based on the complete case analysis, we removed all missing values and applied a proportional odds model to the 4-level scale of vaccine hesitancy predicted by the covariates in the remaining 748 samples. We used the score test to evaluate the proportional odds assumption before fitting the model, and no violation was found in this assumption (P = .1088). Therefore, our proportional odds models shared the same coefficient parameter in each covariate across the logits. We used a cumulative logit function by contrasting lower and higher vaccine hesitancy levels. For example, if the response variable of getting the COVID-19 vaccine for the i^th subject Y_ij has j = 4 levels (1 = very unlikely to get the vaccine, 2 = unlikely, 3 = likely, 4 = very likely), the cumulative probability of vaccine hesitancy can be denoted as θ_ij = P(Y_i ≤ j). Thus, our proportional odds model consists of 3 model equations of logit(θ_ij), predicted by 19 covariates, where

The variance inflation factors of all covariates were less than 10, so multicollinearity is not a problem in our models. We transformed each estimated coefficient into an odds ratio (OR) by exponential function to explain the odds of being more unlikely (versus more likely) to get the COVID-19 vaccine in the next 6 months.

Data management and analysis were performed in SAS version 9.4 (SAS Institute Inc., Cary, NC). The significance level was set at P < .05.

Results

Table 1 shows the demographic breakdown of the sample population and the demographic estimates for the state of Nevada.³⁵ The majority (68.9%) of study respondents identified as White, followed by Hispanic (13.2%). Slightly over half (54.9%) were female, 38% had a college degree or higher, and 44.8% were aged 65 years or older. The race/ethnicity data were collected somewhat differently than the population estimates for the state. The survey listed the category “Hispanic, Latino(a), or Spanish” in the list of race and ethnicities, and respondents were allowed to choose multiple race and ethnicity categories; 11.8% of respondents chose the “Hispanic, Latino(a), or Spanish” category alone, and 1.5% chose it in some combination. This differs from the Nevada population estimates, which use the Census Bureau's American Community Survey categories that prompt all respondents to choose Hispanic or non-Hispanic ethnicity. The race category of White is overrepresented, while Hispanic, Asian, and Other appear to be underrepresented in our sample. Respondents had slightly higher educational attainment and older age than the state estimates.

Table 1.

Comparison of Respondent Demographics in December 2020 and Nevada State Estimates in January 2021 (N = 1,000)

Characteristics	Sample n (%)	Nevada n (%)^a
Race and ethnicity
White	670 (68.9)	1,898,794 (60.2)
Hispanic, Latino(a), or Spanish (alone or in combination)	128 (13.2)	956,801 (30.3)
Black or African American	81 (8.3)	309,981 (9.8)
Asian	27 (2.8)	272,240 (8.6)
American Indian or Alaskan Native	13 (1.3)	38,058 (1.2)
Native Hawaiian or other Pacific Islander	10 (1.0)	21,771 (0.7)
Other race or ethnicity	29 (3.0)	432,717 (13.7)
2 or more races	14 (1.4)	180,674 (5.7)
Gender
Male	447 (45.1)	1,578,893 (50.1)
Female	544 (54.9)	1,575,339 (49.9)
Education
Less than high school diploma	33 (3.3)	289,073 (13.2)^b
High school graduate (grade 12 or GED)	218 (22.1)	614,329 (28.1)^b
Some college or technical school (1 to 3 years)	361(36.6)	741,948 (34.0)^b
College graduate (4 or more years)	196 (19.9)	351,837 (16.1)^b
Graduate or professional degree	179 (18.1)	186,617 (8.6)^b
Age, years
18 to 24	63 (6.4)	262,550 (8.3)
25 to 44	180 (18.3)	864,958 (27.4)
45 to 64	300 (30.5)	791,452 (25.1)
65 and over	441 (44.8)	527,394 (16.7)

Source: Healthy Southern Nevada, 2021 demographics³⁵; ^beducational attainment of population aged 25 years or older.

Table 2 shows that 30.4% (n = 304) of 1,000 respondents were very unlikely or unlikely to get the COVID-19 vaccine if available in the next 6 months. The following covariates had a significant univariate association with vaccine hesitancy: age (P < .001), race (P < .001), education level (P < .001), health status (P = .004), conservative view (P < .001), liberal view (P < .001), worrying about infection (P < .001), living with children under the age of 18 years (P < .001), testing positive for COVID-19 (P = 0.03), worrying about becoming severely ill from COVID-19 (P < .001), worrying about dying from COVID-19 (P < .001), worrying when thinking about COVID-19 (P < .001), agreeing that COVID-19 poses a large health risk (P < .001), and maintaining social distancing (P < .001).

Table 2.

Frequencies and Proportions in Covariates by Vaccine Hesitancy from a Sample of Nevadan Adults in December 2020 (N = 1,000)

	Very Likely	Likely	Unlikely	Very Unlikely
	(n = 495)	(n = 201)	(n = 123)	(n = 181)
Variable	n (%)	n (%)	n (%)	n (%)	P Value^a
Age, years (n = 999)^b					< .001
18 to 29	53 (35.33)	48 (32.00)	23 (15.33)	26 (17.33)
30 to 44	40 (33.90)	27 (22.88)	19 (16.10)	32 (27.12)
45 to 64	120 (40.96)	51 (17.41)	46 (15.70)	76 (25.94)
65 and over	281 (64.16)	75 (17.12)	35 (7.99)	47 (10.73)
Race and ethnicity (n = 972)^b					< .001
Non-Hispanic White	365 (54.48)	119 (17.76)	72 (10.75)	114 (17.01)
Hispanic, Latino(a), or Spanish	33 (30.84)	32 (29.91)	25 (23.36)	17 (15.89)
Non-Hispanic African American or Black	36 (45.57)	18 (22.78)	10 (12.66)	15 (18.99)
Non-Hispanic Asian	14 (51.85)	7 (25.93)	4 (14.81)	2 (7.41)
Multiple or other races	36 (40.45)	19 (21.35)	10 (11.24)	24 (26.97)
Gender (n = 991)^b					.73
Female	213 (47.65)	94 (21.03)	57 (12.75)	83 (18.57)
Male	279 (51.29)	106 (19.49)	65 (11.95)	94 (17.28)
Education (n = 987)^b					< .001
Less than high school diploma	12 (36.36)	6 (18.18)	6 (18.18)	9 (27.27)
High school graduate (grade 12 or GED)	92 (42.20)	52 (23.85)	27 (12.39)	47 (21.56)
Some college or technical school (1 to 3 years)	165 (45.71)	62 (17.17)	55 (15.24)	79 (21.88)
College graduate (4 or more years)	109 (55.61)	41 (20.92)	24 (12.24)	22 (11.22)
Graduate or professional degree	110 (61.45)	36 (20.11)	11 (6.15)	22 (12.29)
Health status (n = 996)^b					.004
Poor or fair	133 (56.12)	38 (16.03)	27 (11.39)	39 (16.46)
Good	161 (48.06)	82 (24.48)	47 (14.03)	45 (13.43)
Very good or excellent	198 (46.70)	80 (18.87)	49 (11.56)	97 (22.88)
Income (n = 818)^b					.12
$0 to $30,000	99 (43.23)	47 (20.52)	33 (14.41)	50 (21.83)
$30,001 to $65,000	113 (50.22)	44 (19.56)	28 (12.44)	40 (17.78)
$65,001 to $105,000	85 (45.45)	42 (22.46)	27 (14.44)	33 (17.65)
$105,001 or more	103 (58.19)	27 (15.25)	13 (7.34)	34 (19.21)
I generally take the conservative view on most issues (n = 949)^b					< .001
Strongly agree	115 (41.97)	53 (19.34)	33 (12.04)	73 (26.64)
Agree	146 (41.36)	87 (24.65)	50 (14.16)	70 (19.83)
Disagree	108 (57.75)	40 (21.39)	23 (12.30)	16 (8.56)
Strongly disagree	99 (73.33)	11 (8.15)	10 (7.41)	15 (11.11)
I generally take the liberal view on most issues (n = 940)^b					< .001
Strongly agree	104 (78.20)	11 (8.27)	9 (6.77)	9 (6.77)
Agree	153 (51.52)	67 (22.56)	40 (13.47)	37 (12.46)
Disagree	118 (43.22)	65 (23.81)	36 (13.19)	54 (19.78)
Strongly disagree	86 (36.29)	48 (20.25)	30 (12.66)	73 (30.80)
How worried are you about you or your loved one becoming infected with COVID-19?					< .001
Very worried	218 (60.89)	75 (20.95)	37 (10.34)	28 (7.82)
Somewhat worried	243 (57.45)	86 (20.33)	55 (13.00)	39 (9.22)
Not worried at all	34 (15.53)	40 (18.26)	31 (14.16)	114 (52.05)
Do you have children under the age of 18 that live in the household?					< .001
Yes	84 (36.21)	52 (22.41)	36 (15.52)	60 (25.86)
No	411 (53.52)	149 (19.40)	87 (11.33)	121 (15.76)
Do you have a spouse or partner?					.13
Yes	305 (50.83)	111 (18.50)	67 (11.17)	117 (19.50)
No	190 (47.50)	90 (22.50)	56 (14.00)	64 (16.00)
Have you ever tested positive for COVID-19? (n = 995)^b					.034
Yes	41 (37.27)	25 (22.73)	20 (18.18)	24 (21.82)
No	452 (51.07)	174 (19.66)	102 (11.53)	157 (17.74)
How worried are you about you or your loved one becoming severely ill from COVID-19?					< .001
Very worried	249 (61.18)	84 (20.64)	40 (9.83)	34 (8.35)
Somewhat worried	202 (56.27)	69 (19.22)	49 (13.65)	39 (10.86)
Not worried at all	44 (18.80)	48 (20.51)	34 (14.53)	108 (46.15)
How worried are you about you or your loved one dying due to COVID-19?					< .001
Very worried	206 (58.36)	73 (20.68)	46 (13.03)	28 (7.93)
Somewhat worried	205 (63.08)	61 (18.77)	32 (9.85)	27 (8.31)
Not worried at all	84 (26.09)	67 (20.81)	45 (13.98)	126 (39.13)
Select how you feel at this moment, when thinking about COVID-19					< .001
Very worried	152 (65.80)	46 (19.91)	18 (7.79)	15 (6.49)
Somewhat worried	280 (56.68)	102 (20.65)	60 (12.15)	52 (10.53)
Not worried at all	63 (22.91)	53 (19.27)	45 (16.36)	114 (41.45)
Do you use social media sites such as Facebook or NextDoor to find out neighborhood happenings/events, or to stay in touch with community members? (n = 997)^b					.86
Yes	194 (50.92)	76 (19.95)	43 (11.29)	68 (17.85)
No	299 (48.54)	125 (20.29)	79 (12.82)	113 (18.34)
I believe COVID-19 poses a large health risk to my community					< .001
Strongly agree	343 (67.39)	73 (14.34)	58 (11.39)	35 (6.88)
Agree	133 (42.90)	94 (30.32)	39 (12.58)	44 (14.19)
Disagree	16 (14.04)	25 (21.93)	20 (17.54)	53 (46.49)
Strongly disagree	3 (4.48)	9 (13.43)	6 (8.96)	49 (73.13)
In general, I have followed the government guidelines concerning appropriate social distance from others in response to COVID-19					< .001
Strongly agree	345 (63.07)	99 (18.10)	48 (8.78)	55 (10.05)
Agree	149 (40.16)	87 (23.45)	64 (17.25)	71 (19.14)
Disagree	0 (0.00)	7 (16.67)	7 (16.67)	28 (66.67)
Strongly disagree	1 (2.50)	8 (20.00)	4 (10.00)	27 (67.50)
Area					.44
Rural	422 (49.71)	175 (20.61)	105 (12.37)	147 (17.31)
Urban	73 (48.34)	26 (17.22)	18 (11.92)	34 (22.52)

The P value was calculated using a chi-square test; ^bNot all respondents replied to the statement or question.

Table 3 shows that within the sample of 748 respondents (described in the statistical analysis section), age, race, gender, annual income, conservative view, worrying about infection, agreeing that COVID-19 poses a large health risk, and maintaining social distancing were significantly associated with vaccine hesitancy. Specifically, people aged 65 years or older had significantly lower odds of vaccine hesitancy than those aged 18 to 29 years (OR = 0.33; 95% CI, 0.19 to 0.57). Compared with non-Hispanic White individuals, the odds of vaccine hesitancy were significantly higher by 2.43 times (95% CI, 1.41 to 4.17) among non-Hispanic African American/Black individuals and 1.92 times higher (95% CI, 1.12 to 3.27) among respondents who identified as multiple or other races. Men had lower odds of vaccine hesitancy than women by 0.63 times (95% CI, 0.46 to 0.87). People with annual incomes higher than $105,000 also had significantly lower odds of vaccine hesitancy than those with annual incomes below $30,000 (OR = 0.49; 95% CI, 0.30 to 0.81). People with conservative views on most issues were more likely to exhibit vaccine hesitancy than others (OR = 1.95; 95% CI, 1.08 to 3.53 for “agree”). People who were somewhat worried about themselves and loved ones being infected had significantly lower odds of vaccine hesitancy by 0.47 times (95% CI, 0.26 to 0.85). People who strongly agreed that COVID-19 poses a large health risk to their communities had significantly lower odds of vaccine hesitancy than those who strongly disagreed by 0.12 times (95% CI, 0.05 to 0.29).

Table 3.

Odds Ratios of Vaccine Hesitancy for Covariates from a Sample of Nevada Adults in December 2020 (n = 748)

Variable	OR	95% CI	P Value	VIF
Age, years			< .001	1.34
18 to 29		Reference
30 to 44	0.92	0.50-1.68
45 to 64	0.96	0.57-1.61
65 and over	0.33	0.19-0.57
Race and ethnicity			.007	1.10
Non-Hispanic White		Reference
Hispanic, Latino(a), or Spanish	1.63	0.97-2.74
Non-Hispanic Black or African American	2.43	1.41-4.17
Non-Hispanic Asian	1.37	0.56-3.38
Multiple or other races	1.92	1.12-3.27
Gender			.005	1.11
Male	0.63	0.46-0.87
Female		Reference
Education			.7090	1.21
Less than high school diploma		Reference
High school graduate (grade 12 or GED)	0.69	0.28-1.73
Some college or technical school (1 to 3 years)	0.85	0.35-2.05
College graduate (4 or more years)	0.72	0.28-1.82
Graduate or professional degree	0.65	0.25-1.67
Health status			.3990	1.13
Poor or fair		Reference
Good	0.83	0.55-1.27
Very good or excellent	1.07	0.70-1.62
Income			.0372	1.34
$0 to $30,000		Reference
$30,001 to $65,000	0.74	0.49-1.11
$65,001 to $105,000	0.85	0.54-1.34
$105,001 or more	0.49	0.30-0.81
I generally take the conservative view on most issues.			.0269	1.69
Strongly agree	1.82	0.97-3.39
Agree	1.95	1.08-3.53
Disagree	1.11	0.59-2.09
Strongly disagree		Reference
I generally take the liberal view on most issues.			.1114	1.87
Strongly agree	0.44	0.22-0.87
Agree	0.77	0.46-1.30
Disagree	0.72	0.44-1.17
Strongly disagree		Reference
How worried are you about you or your loved one becoming infected with COVID-19?			.0454	3.22
Very worried	0.53	0.26-1.08
Somewhat worried	0.47	0.26-0.85
Not worried at all		Reference
Do you have children under the age of 18 that live in the household?			.0767	1.21
Yes	1.44	0.96-2.16
No		Reference
Do you have a spouse or partner?			.3562	1.23
Yes	0.85	0.60-1.20
No		Reference
Have you ever tested positive for COVID-19?			.9092	1.06
Yes	1.03	0.64-1.66
No		Reference
How worried are you about you or your loved one becoming severely ill from COVID-19?			.7555	4.18
Very worried	1.24	0.54-2.83
Somewhat worried	1.29	0.66-2.54
Not worried at all		Reference
How worried are you about you or your loved one dying due to COVID-19?			.0786	2.76
Very worried	0.75	0.41-1.36
Somewhat worried	0.57	0.34-0.94
Not worried at all		Reference
Select how you feel at this moment, when thinking about COVID-19			.0753	2.34
Very worried	0.48	0.25-0.90
Somewhat worried	0.70	0.43-1.14
Not worried at all		Reference
Do you use social media sites such as Facebook or NextDoor to find out neighborhood happenings/events, or to stay in touch with community members?			.7003	1.06
Yes	1.07	0.77-1.48
No		Reference
I believe COVID-19 poses a large health risk to my community.			< .001	2.38
Strongly agree	0.12	0.05-0.29
Agree	0.17	0.07-0.39
Disagree	0.35	0.16-0.77
Strongly disagree		Reference
In general, I have followed the government guidelines concerning appropriate social distance from others in response to COVID-19.			.004	1.65
Strongly agree	0.40	0.14-1.09
Agree	0.56	0.21-1.50
Disagree	1.85	0.55-6.25
Strongly disagree		Reference
Area			.2575	1.05
Urban	1.31	0.82-2.07
Rural		Reference

Abbreviations: CI, confidence interval; GED, General Educational Development test; OR, odds ratio; VIF, variance inflation factor.

Discussion

This survey of Nevada adults, conducted just after the first 2 COVID-19 vaccines were authorized for emergency use, inquired about factors potentially relevant to vaccination uptake. Using the proportional odds model, we found that older adults, men, people worried about the impact of COVID-19 or concerned about how it might affect the health of their communities, those following government social distancing guidelines, and people with higher incomes had less vaccine hesitancy than their counterparts. African American or Black respondents and those identifying as being of multiple or other races all had greater vaccine hesitancy than their White counterparts. People who self-identified as conservative also exhibited greater vaccine hesitancy.

We found that almost a third (30.4%) of the respondents were either very unlikely or unlikely to get the COVID-19 vaccine in December 2020, just after initial emergency use authorization was received for 2 of the vaccines. Our findings indicated a relatively high vaccine hesitancy in this sample and are similar to other national studies conducted.^30,53,54 However, as COVID-19 vaccines become more readily available in the United States (now available to anyone aged 5 years or older), hesitancy rates generally have declined. The Kaiser Family Foundation's ongoing research project that tracks attitudes about and experiences with COVID-19 vaccinations²⁹ found that those who reported they would get vaccinated “only if required” fell from 9% in December 2020 to 3% in July 2021, and those reporting they would “wait and see” fell from 39% to 10%. However, those who reported they would “definitely not” get vaccinated has remained steady at about 14%. It is worth noting that the percentage of respondents who reported they were “already vaccinated” or would be “as soon as possible” increased from 34% to 70%,²⁹ yet only 61% of Americans in August had received at least 1 dose of the vaccine.²³ Thus, it seems that enthusiasm and hesitancy rates reflected by the survey respondents are not necessarily reflective of actual vaccine behaviors in the US population at large. Of the Kaiser Family Foundation survey respondents, 27% reported hesitancy in July 2021, which is similar to the rate from our survey in December 2020. Nonetheless, vaccine hesitancy and the percentage of the population that remains unvaccinated will certainly continue to hinder the COVID-19 response. This discussion explores reasons for such hesitancy.

The perceived threat of COVID-19 was one of the constructs examined in this study as a commonly known factor for vaccine hesitancy. “Perceived threat” is created by combining 2 constructs—perceived severity and perceived susceptibility—from the Health Belief Model to understand a motivate behavior change.⁵⁵ Our study found that worry about self or loved ones getting severely ill from, dying from, or generally worrying about COVID-19 were not significantly associated with vaccine hesitancy. The only aspect of the perceived threat construct significantly associated with lower vaccine hesitancy was being somewhat worried about contracting COVID-19. Our overall findings related to perceived threat were somewhat contrary to the findings from Khubchandani et al³⁰ who operationalized a stunted version of measuring this construct and found it to be a strong predictor. The perceived threat construct has been shown to be a weak predictor of behavior change,^56,57 and our study findings were in consonance with that assertion. Our findings imply that it may be counterproductive for vaccination campaigns to emphasize perceived threat or “fear generation” as a vaccine motivator. Instead, messages about improving value expectancy, building self-efficacy⁵⁸ and behavioral confidence, and ensuring changes in the physical environment⁵⁹ as suggested in contemporary health behavior research literature may be more effective.

Taking a conservative view on most issues was associated with high vaccine hesitancy. This finding is similar to findings from other studies,^30,53 suggesting that a conservative viewpoint is a potential barrier to universal COVID-19 immunizations. There is a need for conservative leaders to openly support COVID-19 vaccination campaigns, serve as role models themselves, and actively advocate for vaccination uptake.

Compared with younger adults (ages 18 to 29 years), older adults (ages 65 years or older) demonstrated lower vaccine hesitancy. This is understandable given the high COVID-19 pervasiveness, severity, and mortality in the older age group.⁶⁰ However, the literature is mixed about this finding. Some studies have not found this association^30,54,56,57 while others have.^47,61 This variation could be attributed to methodology, as some studies have defined older adults as 55 years and older, some as 60 years and older, for example, and all studies used convenience sampling.

Those who identified as African American/Black and multiple or other races in this study demonstrated higher vaccine hesitancy than White respondents. This finding is similar to other studies⁶¹ and suggests a need for campaigns directed toward these communities. Reasons for higher vaccine hesitancy in the African American/Black community are multifarious and include mistrust of the government and healthcare, reduced access to care, less research with African American study respondents, lower educational attainment, and others.⁶² It should also be noted that communities of color are more likely to experience structural barriers preventing access to vaccines⁶³ and have suffered more from unintended consequences of mitigation strategies, such as unemployment, loss of healthcare coverage, and housing instability.⁶⁴ Given that mistrust and structural barriers stem from a long history and systems of inequity, it may be challenging to allay all fears and barriers. But the development of culturally appropriate and evidence-based information, equitable access to available vaccines, collaboration with healthcare providers, and channelizing role models through formal and informal leaders is one place to start.^26,62

Our study also found that men were less hesitant than women in their likelihood of getting the COVID-19 vaccine, a finding supported by other studies.^{29,30,47,53,54} The reasons for this are unclear, but possibly men have less worry about the vaccine's side effects or are overburdened with death from COVID-19 and other chronic conditions.^65,66 There is a need to work with women-focused organizations and other groups to promote COVID-19 vaccination among women. We also found higher incomes associated with lower vaccine hesitancy, consistent with previous findings.^{29,30,47,53,54} Vaccination efforts should prioritize and target groups with higher hesitancy.

An interesting finding of our study was that respondents who believed strongly that COVID-19 posed a risk to their community were more likely to have lower vaccine hesitancy. This seems to reflect American altruism^67,68 and investment in social capital.⁶⁹ COVID-19 vaccine campaigns should build on the appeal to altruism and social capital among the US population.

Finally, people following government social distancing guidelines were less hesitant to receive the COVID-19 vaccine. Both adherence to social distancing and lower vaccine hesitancy may indicate appreciation of the severity of the pandemic. The high levels of availability of the COVID-19 vaccine in the United States to everyone aged 5 years and older should help advance the goal of universal COVID-19 vaccination.

Strengths and Limitations of the Study

This study remains timely, as there is an urgent need to curtail the progression of COVID-19 through mass vaccination, especially in light of the more transmissible Delta variant and the recent addition of a booster dose to the vaccine series. Not only can these findings be used to inform targeted COVID-19 interventions in Nevada and across the United States, but the determinants identified here may help pave the way for informing the design of more efficacious and effective vaccination efforts nationally for years to come, given that today's demographic profile of Nevada is representative of the United States in about 20 years.

This study also had some limitations. The cross-sectional study design restricts the establishment of causality because information on antecedents and outcomes is collected simultaneously. We relied on a self-designed instrument based on the literature and did not test for all psychometric properties except for internal consistency reliability. Data were collected through self-reporting, an appropriate method since we were interested in the perceptions of our target population, although it is amenable to several biases. Our study did not use an explicit behavioral theoretical framework or study all aspects related to vaccine hesitancy, such as protection duration or efficacy, for example.⁷⁰ The study did not capture occupational data to understand if respondents were frontline and essential workers or workers able to work from home, which may have influenced perceived risk and hesitancy rates. Many of our questions were measured using Likert scales, which have their own inherent strengths and limitations. The population demographics of the study sample and Nevada did not fully align (ie, the study population collectively reported it was older, more White, less Hispanic, less “other race or ethnicity,” and more educated), limiting generalizability within Nevada and also highlighting the importance of oversampling groups that are younger, non-White, Hispanic, and with lower educational attainment in vaccine hesitancy survey research. Generalizability also may be limited due to the geographical restriction to Nevada, although as discussed, in some important ways Nevada resembles the United States as a whole. Finally, COVID-19 and response efforts are rapidly changing. Vaccine hesitancy today may look different than at the time of the survey, as vaccination strategies have morphed and variants have shifted the COVID-19 landscape. Findings from this study remain important despite these shifts because lessons from the initial rollout of the COVID-19 vaccine may be relevant in booster doses and future pandemics.

Conclusions

Findings from this study identified determinants of COVID-19 vaccine hesitancy among Nevada adults, and because the state's demographics are similar to the greater United States, these findings can inform current and future national vaccination efforts. Our findings support a need for interventions targeting certain demographic groups, specifically younger and middle-aged adults, the African American/Black community, people identifying as multiple or “other” races, women, and those with lower incomes. Moreover, instead of focusing on addressing the construct of the perceived threat to COVID-19, behavior change interventions designed around other aspects of evidence-based behavioral approaches are likely to be more effective.^71,72 Such approaches should form the basis of immunization campaigns. Leaders of African American communities, conservative groups, organizations focused on women, and others should collaborate to support universal COVID-19 immunization efforts. Finally, the zeal of American altruism and social capital could be tapped for immunization efforts.

Footnotes

Acknowledgments

This project was partially supported by the US Centers for Disease Control and Prevention as part of a subaward totaling $3.4 million from the Nevada Division of Public and Behavioral Health's Epidemiology and Laboratory Capacity award. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement by, the US Centers for Disease Control and Prevention or the US government.

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