Longitudinal assessment of COVID-19 vaccine uptake: A two-wave survey of a nationally representative U.S. sample

Understanding factors that influence those who are initially COVID-19 vaccine hesitant to accept vaccination is valuable for the development of vaccine promotion strategies. Using Ipsos KnowledgePanel®, we conducted a national survey of adults aged 18 and older in the United States. We created a questionnaire to examine factors associated with COVID-19 vaccine uptake over a longitudinal period ("Wave 1" in April 2021 and "Wave 2" in February 2022), and utilized weighted data provided by Ipsos to make the data nationally representative. Overall, 1189 individuals participated in the Wave 1 survey, and 843 participants completed the Wave 2 survey (71.6% retention rate). Those who intended to be vaccinated as soon as possible ("ASAP") were overwhelmingly vaccinated by Wave 2 (96%, 95% CI: 92% to 100%). Of those who initially wished to delay vaccination until there was more experience with it ("Wait and See"), 57% (95% CI: 47% to 67%) were vaccinated at Wave 2. Within the "Wait and See" cohort, those with income <$50,000 and those who had never received the influenza vaccine were significantly less likely to be vaccinated at Wave 2. Among those who initially indicated that they would not receive a COVID-19 vaccine ("Non-Acceptors"), 28% (95% CI: 21% to 36%) were vaccinated at Wave 2. Those who believed COVID-19 was not a major problem in their community were significantly less likely to be vaccinated, while those with more favorable attitudes toward vaccines in general and public health strategies to decrease the impact of COVID-19 were significantly more likely to be vaccinated. Overall, barriers to vaccine uptake for the "Wait and See" cohort appear to be more practical, whereas barriers for the "Non-Acceptor" cohort seem to be more ideological. These findings will help target interventions to improve uptake of COVID-19 boosters and future novel vaccines.

County-level correlates of completed HPV vaccination in Indiana

The Healthy People 2030 goal is for 80% of all adolescents to complete their HPV vaccination series. Per the 2021, National Immunization Survey-Teen (NIS-Teen), 61.7% of adolescents have completed the series, and Indiana lags below the national average (55.2%). The present study estimated the 2-dose HPV vaccine series completion rates across Indiana counties among individuals aged 9-14 years who received their first dose of vaccine and determined what factors were associated with series completion at the county level. The association of county-level sociodemographic and health measures with series completion was also examined. Data were extracted from the Indiana Immunization Information System (IIS), administered by the Indiana Department of Health. All vaccine providers are required to report all immunizations to the system for any patient under age 19 years. All Indiana children ages 9-14 years at the time of first dose who had initiated HPV vaccination in 2017 or 2018 were included. Two-dose series completion was evaluated through October of 2020, allowing a minimum gap of 22 months from first dose administration. All statistical analyses were conducted at the county-level. The Indiana HPV vaccination series completion rate among individuals that received the first dose was on average 73% across counties, ranging from 55.7% to 90.4%. Higher series completion was positively associated with primary care providers per capita, participation in mammography screening among Medicare enrollees, median household income, life expectancy, percentage of residents with some college, percentage of adults up-to-date with colonoscopy screening, and percentage of adults with flu vaccine. There was wide variability in series completion across Indiana counties. HPV series completion was associated with county-level sociodemographic and health measures, particularly variables reflecting difficulties with access to care and lack of financial resources.

Human Papillomavirus Vaccination and Social Media: Results in a Trial With Mothers of Daughters Aged 14-17

Introduction: Parents acquire information about human papillomavirus (HPV) vaccines online and encounter vaccine-critical content, especially on social media, which may depress vaccine uptake. Secondary analysis in a randomized trial of a Facebook-delivered adolescent health campaign targeting mothers with posts on HPV vaccination was undertaken with the aims of (a) determining whether the pre–post-change occurred in self-reports of the mothers on HPV vaccination of their adolescent daughters; (b) describing the comments and reactions to vaccine posts; (c) exploring the relationship of campaign engagement of the mothers assessed by their comments and reactions to posts to change in the self-reports of the mothers of HPV vaccination.

Materials and Methods: Mothers of daughters aged 14–17 were recruited from 34 states of the US (n = 869). A social media campaign was delivered in two Facebook private groups that differed in that 16% of posts in one were focused on indoor tanning (IT) and 16% in the other, on prescription drug misuse, assigned by randomization. In both groups, posts promoted HPV vaccination (n = 38 posts; no randomization) and vaccination for other disease (e.g., influenza, n = 49). HPV and other vaccination posts covered the need for a vaccine, the number of adolescents vaccinated, how vaccines are decreasing the infection rates, and stories of positive benefits of being vaccinated or harms from not vaccinating. Guided by social cognitive theory and diffusion of innovations theory, posts were intended to increase knowledge, perceived risk, response efficacy (i.e., a relative advantage over not vaccinated daughters), and norms for vaccination. Some vaccination posts linked to stories to capitalize on identification effects in narratives, as explained in transportation theory. All mothers received the posts on vaccination (i.e., there was no randomization). Mothers completed surveys at baseline and 12- and 18-month follow-up to assess HPV vaccine uptake by self-report measures. Reactions (such as sad, angry) and comments to each HPV-related post were counted and coded.

Results: Initiation of HPV vaccination (1 dose) was reported by 63.4% of mothers at baseline, 71.3% at 12-month posttest (pre/post p < 0.001), and 73.3% at 18-month posttest (pre/post p < 0.001). Completion of HPV vaccination (two or three doses) was conveyed by 50.2% of mothers at baseline, 62.5% at 12-month posttest (pre/post p < 0.001), and 65.9% at 18-month posttest (pre/post p < 0.001). For posts on HPV vaccines, 8.1% of mothers reacted (n = 162 total), and 68.4% of posts received a reaction (63.2% like; 13.2% love, 7.9% sad). In addition, 7.6% of mothers commented (n = 122; 51 unfavorable, 68 favorable, 1 neutral), and 50.0% of these posts received a comment. There were no differences in pre–post change in vaccine status by the count of reactions or comments to HPV vaccine posts (Ps > 0.05). Baseline vaccination was associated with the valence of comments to HPV vaccine posts (7.2% of mothers whose daughters had completed the HPV series at baseline made a favorable comment but 7.6% of mothers whose daughters were unvaccinated made an unfavorable comment).

Conclusion: Effective strategies are needed in social media to promote HPV vaccines and counter misinformation about and resistance to them. Mothers whose daughters complete the HPV vaccine course might be recruited as influencers on HPV vaccines, as they may be predisposed to talk favorably about the vaccine. Comments from mothers who have not been vaccinated should be monitored to ensure that they do not spread vaccine-critical misinformation. Study limitations included lack of randomization and control group, relatively small number of messages on HPV vaccines, long measurement intervals, inability to measure views of vaccination posts, reduced generalizability related to ethnicity and social media use, and use of self-reported vaccine status.

Clinical Trial Registration:www.clinicaltrials.gov, identifier NCT02835807.

Vacteens.org: A Mobile Web app to Improve HPV Vaccine Uptake

U.S. HPV vaccine uptake remains below the Healthy People 2030 goal of 80% series completion. Parental concerns and misinformation about the efficacy and safety of the Human Papillomavirus (HPV) vaccine remain, and may be addressed by digital interventions tailored to their concerns. Reported here are results from a small scale randomized trial testing a mobile web app for parents and their adolescent daughters (ages 11–14 years) encouraging HPV vaccination in New Mexico, an ethnically-diverse U.S. state.

Methods: A clinic-cluster randomized trial where pediatric clinics (n = 9) were recruited and randomized, and parent-adolescent pairs (n = 82) within clinics received either the Vacteens.org/Vacunadolescente.org mobile web app or Usual and Customary (UC) HPV Vaccination information. Parents completed online surveys at baseline and 3-months. Daughters' HPV vaccine data were collected from the New Mexico State Immunization Information System 1 year post baseline.

Results: Three month survey results found Vacteens.org/Vacunadolescente.org parents to have higher positive HPV vaccine beliefs, informed decision making, intent to vaccinate and vaccine confidence outcomes than UC parents. HPV vaccine data found higher first dose HPV vaccination (Pearson χ² = 6.13, p = 0.013, Vacteens.org/Vacunadolescente.org group 59.4%, UC group 40.6%), and higher HPV vaccination series completion (Pearson χ² = 6.49, p = 0.011, Vacteens.org/Vacunadolescente.org group 68.4%, UC group 31.6%).

Conclusions: The small trial results showed the Vacteens.org/Vacunadolescente.org web app prompted positive vaccine-related attitudes and beliefs, and more HPV vaccination initiation and series completion. Mobile web apps can make decision-making tools for HPV vaccination widely available on digital platforms, reducing vaccine hesitancy, and confusion and increase HPV vaccine uptake.

Trends in Prevalence of Protective Levels of Hepatitis B Surface Antibody Among Adults Aged 18-49 Years With Risk Factors for Hepatitis B Virus Infection-United States, 2003-2014

BACKGROUND

Hepatitis B virus (HBV) infection can be prevented through vaccination. However, previous data show that only about 24%-45% of US adults at high risk of HBV infection are protected. Our aims were to assess prevalence and trends in protective levels of hepatitis B surface antibody (anti-HBs) from 2003 to 2014 and explore factors associated with protection among adults at high risk.

METHODS

Data were taken from the 2003-2014 National Health and Nutrition Examination surveys. Our sample included adults aged 18-49 years who were tested for HBV and reported at least 1 of the following infection risks: history of sexually transmitted disease, sex with men (for men), infection with human immunodeficiency virus, and injection drug use. We calculated the prevalence of anti-HBs (≥10 mIU/mL), indicative of immunity from vaccination, among respondents for three 4-year time intervals (2003-2006, 2007-2010, and 2011-2014) and applied the Cochran-Mantel-Haenszel test to assess trends. Using multivariable logistic regression, we examined factors associated with positive anti-HBs serology.

RESULTS

The prevalence of positive anti-HBs serology was 23.4%. Prevalence increased from 2003-2006 (16.3%) to 2007-2010 (27.3%), but no change occurred from 2007-2010 (27.3%) to 2011-2014 (28.1%). Among factors predicting positive anti-HBs serology were young age and higher education.

CONCLUSIONS

By 2014, less than one-third of adults aged 18-49 years at risk of infection exhibited protective antibodies ≥10 mIU/mL. Because these adults account for a majority of unprotected adults, targeted intervention strategies are essential to achieve the hepatitis B elimination goal.

The effects of message framing and healthcare provider recommendation on adult hepatitis B vaccination: A randomized controlled trial

Many adults in the U.S. do not receive recommended vaccines, and the research literature remains inconclusive on the best communication strategies for increasing this behavior. This study examined the association of message framing (gained-framed vs. loss-framed vs. control), and healthcare provider (HCP) recommendation (offered vs. recommended) on uptake of adult hepatitis B virus (HBV) vaccination in a high risk population using a 3 × 2 block design randomized controlled trial. Fear of shots, fear of vaccines, and perceived message framing were examined in secondary analyses. Of the 1747 participants, 47.7% (n = 833) received 0 doses of HBV vaccine, 27.8% (n = 485) received 1 dose, 10.4% received 2 doses, and 14.1% received all 3 recommended doses. There was not a significant interaction between message framing and HCP recommendation (p = .59). Mean number of doses received by the gain-framed group (m = 0.96) was not significantly different from the loss-framed group (m = 0.97, RR = 0.99, 95% CI = 0.88-1.12). However, those receiving any framing message received significantly more doses (m = 0.96) than those in the control condition (m = 0.81, RR = 1.17, 95%CI = 1.06-1.31). Participants who received a HCP recommendation received significantly more vaccine doses (m = 0.95) than those in the vaccine-offered condition (mean = 0.82, RR = 1.16, 95%CI = 1.05-1.28). These results suggest there is no difference in vaccine uptake between gain-frame and loss-frame messages, but both are better than a control message. These results also support advising HCP to provide a strong recommendation for vaccinations beyond merely offering it to patients. This study has implications for vaccine uptake beyond HBV, and can inform future research on effective vaccine communication research. Clinicaltrials.gov Identifier: NCT00739752. Registration date: August 20, 2008.

Insights on HPV vaccination in the United States from mothers' comments on Facebook posts in a randomized trial

In the United States, parents' health beliefs affect HPV vaccination decisions for children. Our team acquired insights into mothers' health beliefs from their reactions and comments to posts on HPV vaccination in a social media adolescent health campaign in a randomized trial (n = 881 mothers; 63.1% reported daughters had 1+ doses of the HPV vaccine) evaluating communication intended to reduce daughters' indoor tanning. A total of 10 HPV vaccination messages in didactic (n = 7) and narrative (n = 3) formats were posted on vaccination need, uptake, and effectiveness and stories of young women who died from cervical cancer and a mother's decision to vaccinate her daughters. These posts received 28 reactions (like, love, and sad buttons; mean = 2.8 per post) and 80 comments (mean = 8.0 per post). More comments were favorable (n = 43) than unfavorable (n = 34). Data was not collected on views for posts. The most common favorable comment reported that daughters were vaccinated (n = 31). Unfavorable comments cited safety concerns, lack of physician support, distrust of pro-vaccine sources, and increased sexual activity of daughters. Mothers posting unfavorable (18.2%) as opposed to favorable (78.6%) comments or not commenting (64.0%) were less likely to have had their daughters vaccinated (chi-square = 22.27, p < 0.001). Favorable comments often did not state reasons for vaccinating. Concerns about lack of vaccine safety remain a barrier. Mothers may express distrust in pro-vaccine sources to reduce discomfort with not vaccinating daughters to reduce their risk for HPV infection. Many mothers who remained silent had vaccinated daughters, which suggests they did not resisit HPV vaccination.

Behavior and health beliefs as predictors of HIV testing among women: a prospective study of observed HIV testing

Much of the research examining predictors of HIV testing has used retrospective self-report to assess HIV testing.

FINDINGS

therefore, may be subject to recall bias and to difficulties determining the direction of associations. In this prospective study, we administered surveys to women in community clinics to identify predictors of subsequent observed HIV testing, overcoming these limitations. Eighty-three percent were tested. In the adjusted multivariable model, being born in the U.S., perceived benefits of testing, worries about being infected with HIV, having had more than 15 lifetime sexual partners, and having had one or more casual sexual partners in the previous three months predicted acceptance of testing. Perceived obstacles to testing predicted non-acceptance. Those who had never been tested for HIV and those tested two to five years previously had greater odds of test acceptance than those who had been tested within the last year. The findings from this study with observed testing as the outcome, confirm some of the results from retrospective, self-report studies. Participants made largely rational decisions about testing, reflecting assessments of their risk and their history of HIV testing. Health beliefs are potentially modifiable through behavioral intervention, and such interventions might result in greater acceptance of testing.

ABBREVIATIONS

HIV: human immunodeficiency virus; AIDS: acquired immune deficiency syndrome; CDC: Centers for Disease Control and Prevention; ACASI: audio computer-assisted self-interview; TRA: theory of reasoned action; HBM: Health Belief Model; STI: sexually transmitted infection; STD: Sexually Transmitted Disease; AOR: adjusted odds ratio; CI: confidence interval.

The effects of HIV testing advocacy messages on test acceptance: a randomized clinical trial

BACKGROUND

Nearly 1 in 5 people living with HIV in the United States are unaware they are infected. Therefore, it is important to develop and evaluate health communication messages that clinicians can use to encourage HIV testing.

METHODS

The objective was to evaluate health communication messages designed to increase HIV testing rates among women and evaluate possible moderators of message effect. We used a randomized four-arm clinical trial conducted at urban community outpatient health clinics involving 1,919 female patients, 18 to 64 years old. The four health message intervention groups were: i) information-only control; ii) one-sided message describing the advantages of HIV testing; iii) two-sided message acknowledging a superficial objection to testing (i.e., a 20 minute wait for results) followed by a description of the advantages of testing; and iv) two-sided message acknowledging a serious objection (i.e., fear of testing positive for HIV) followed by a description of the advantages of testing. The main outcome was acceptance of an oral rapid HIV test.

RESULTS

Participants were randomized to receive the control message (n = 483), one-sided message (n = 480), two-sided message with a superficial objection (n = 481), or two-sided message with a serious objection (n = 475). The overall rate of HIV test acceptance was 83%. The two-sided message groups were not significantly different from the controls. The one-sided message group, however, had a lower rate of testing (80%) than the controls (86%) (OR, 0.66; 95% CI, 0.47-0.93; P = 0.018). "Perceived obstacles to HIV testing" moderated this effect, indicating that the decrease in HIV test acceptance for the one-sided message group was only statistically significant for those who had reported high levels of obstacles to HIV testing (OR, 0.36; 95% CI, 0.19-0.67; P = 0.001).

CONCLUSIONS

None of the messages increased test acceptance. The one-sided message decreased acceptance and this effect was particularly true for women with greater perceived obstacles to testing, the very group one would most want to persuade. This finding suggests that efforts to persuade those who are reluctant to get tested, in some circumstances, may have unanticipated negative effects. Other approaches to messaging around HIV testing should be investigated, particularly with diverse, behaviorally high-risk populations.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00771537. Registration date: October 10. 2008.

Impact of Poor Retention in HIV Medical Care on Hepatitis B Vaccination

BACKGROUND

We identified factors associated with complete hepatitis B vaccination of patients with HIV.

METHODS

Retrospective analysis of patients undergoing HIV clinic orientation from 2000 to 2010. Vaccine-eligible patients had negative hepatitis B serologies at baseline. Receipt of at least 3 doses was defined as complete vaccination.

RESULTS

Of 1242 patients, 519 (42%) were completely vaccinated. Complete vaccination was positively associated with missing ≤25% of the visits during the first year of care (adjusted odds ratio [aOR] = 2.35, 95% confidence interval [CI]: 1.79-3.09), being naive to care (aOR = 1.50, 95% CI: 1.13-1.99), and living at the clinic's county (aOR = 1.33, 95% CI: 1.02-1.75). Complete vaccination was negatively associated with failure to remain in care >2 years (aOR = 0.18, 95% CI: 0.13-0.24), history of intravenous drug use (aOR = 0.48, 95% CI: 0.27-0.87), and baseline CD4 count <200 cells/mm(3) (aOR = 0.69, 95% CI: 0.53-0.92).

CONCLUSION

Poor retention in HIV care is strongly associated with suboptimal hepatitis B vaccination.

Compliance with hepatitis B vaccination among adult males with sexually transmitted infections

Background:

Sexually transmitted infections (STIs) are a diverse group of infections caused by widely differing microorganisms (viruses, protozoa, bacteria, yeasts, ectoparasites and even a nematode), with transmission from person to person by sexual contact as its common characteristic. In all societies, sexually transmitted infections rank among the most common infectious diseases. These patients are at risk for hepatitis B virus infection, but have been relatively neglected in terms of hepatitis B virus vaccination.

Objectives:

In this study, compliance with hepatitis B vaccination among adult males with sexually diseases was examined.

Patients and Methods:

In this survey, 114 males, referred to an infectious diseases clinic, were asked to complete a questionnaire evaluating their knowledge of hepatitis B vaccine, and were interviewed to assess their reasons for refusal or acceptance. Finally, SPSS (version 16) was used to perform the statistical analyses. Variables were analyzed with Chi-square tests.

Results:

The results of this study indicated that the overall hepatitis B vaccine acceptance rate was acceptably high. Among all, 53.5% correctly identified that a vaccine to prevent hepatitis B virus infection had been available, 15% had a negative opinion, and 31.5% were neutral. The rations of all three doses of vaccination were 69.3%.

Conclusions:

Among the respondents, 87% were currently married, 86.8% were currently employed, 17.5% have addiction, 34.2 % used condom, and 36.8% correctly identified hepatitis B as a sexually transmitted infection.

Staying on track: a cluster randomized controlled trial of automated reminders aimed at increasing human papillomavirus vaccine completion

OBJECTIVES

To evaluate whether automated reminders increase on-time completion of the three-dose human papillomavirus (HPV) vaccine series.

METHODS

Ten reproductive health centers enrolled 365 women aged 19-26 to receive dose one of the HPV vaccine. Health centers were matched and randomized so that participants received either routine follow-up (control) or automated reminder messages for vaccine doses two and three (intervention). Intervention participants selected their preferred method of reminders - text, e-mail, phone, private Facebook message, or standard mail. We compared vaccine completion rates between groups over a period of 32 weeks.

RESULTS

The reminder system did not increase completion rates, which overall were low at 17.2% in the intervention group and 18.9% in the control group (p=0.881). Exploratory analyses revealed that participants who completed the series on-time were more likely to be older (OR=1.15, 95% CI 1.01-1.31), report having completed a four-year college degree or more (age-adjusted OR=2.51, 95% CI 1.29-4.90), and report three or more lifetime sexual partners (age-adjusted OR=3.45, 95% CI 1.20-9.92).

CONCLUSIONS

The study intervention did not increase HPV vaccine series completion. Despite great public health interest in HPV vaccine completion and reminder technologies, completion rates remain low.

Hepatitis B testing and vaccination among adults with sexually transmitted infections in a large managed care organization

Data on viral hepatitis B (HBV) testing and vaccination in primary care settings among persons at sexual risk for HBV infection have been sparse. We examined rates and factors associated with HBV serologic testing and vaccination rates in adults infected with sexually transmitted infections. We conducted a retrospective cohort study of adults diagnosed with chlamydia, gonorrhea, or syphilis in Kaiser Permanente Southern California in 2008-2011. The vaccine series initiation was examined in subjects who were tested susceptible. The 90-day hepatitis B surface antigen (HBsAg) testing rate was 28.1% in 15 357 adults. Testing rates increased through the study period. Only 8.8% of patients received both HBsAg and hepatitis B surface antibody tests to determine prior exposure and susceptibility to HBV. Among those who were tested susceptible, 116 (10.6%) subjects initiated the vaccine series. In multivariable logistic regression analysis, the odds of receiving testing was inversely associated with female sex, black race, other/unknown race, or having prespecified chronic comorbidities. In survival analysis, adults aged 25-34 years and ≥55 years were more likely to initiate hepatitis B vaccine series compared with those aged 18-24 years. There are missed opportunities in HBV testing and vaccination in primary care. Implementation of provider decision-making support tools in the electronic medical record system may potentially improve hepatitis B testing and vaccination rates.

Health beliefs and vaccine costs regarding human papillomavirus (HPV) vaccination among a U.S. national sample of adult women

OBJECTIVE

Health beliefs have been found to be significant predictors of vaccine acceptability and uptake, including attitudes about HPV vaccine. In this study, we examined whether the predictive strength of health beliefs varied as a function of vaccine cost among adult women.

METHODS

During April 2009, data were collected from a nationally representative internet sample of 1323 US-resident women aged 27-55 years. Participants completed items related to sociodemographics, health beliefs, and HPV vaccine acceptability. Acceptability was measured at three levels of cost: free, $30/dose, and $120/dose.

RESULTS

Multiple linear regression (MLR) revealed that health belief variables accounted for 29.7% of the variability in overall HPV vaccine acceptability. However, there was a linear and significant decrease in R(2) values from 0.31 for a free vaccine, to 0.25 for a $30/dose vaccine, to 0.11 for a $120/dose vaccine.

CONCLUSION

The results confirm previous findings that health beliefs predict HPV vaccine acceptability. However, the predictive strength of the association decreased with increasing cost. These findings suggest that interventions designed to increase vaccination by modifying health beliefs may have limited effect unless cost is minimized as a barrier.

Can self-prediction overcome barriers to Hepatitis B vaccination? A randomized controlled trial

OBJECTIVE

Hepatitis B virus (HBV) infection remains a serious public health problem, due in part to low vaccination rates among high-risk adults, many of whom decline vaccination because of barriers such as perceived inconvenience or discomfort. This study evaluates the efficacy of a self-prediction intervention to increase HBV vaccination rates among high-risk adults.

METHOD

Randomized controlled trial of 1,175 adults recruited from three sexually transmitted disease clinics in the United States over 28 months. Participants completed an audio-computer-assisted self-interview, which presented information about HBV infection and vaccination, and measured relevant beliefs, behaviors, and demographics. Half of participants were assigned randomly to a "self-prediction" intervention, asking them to predict their future acceptance of HBV vaccination. The main outcome measure was subsequent vaccination behavior. Other measures included perceived barriers to HBV vaccination, measured prior to the intervention.

RESULTS

There was a significant interaction between the intervention and vaccination barriers, indicating the effect of the intervention differed depending on perceived vaccination barriers. Among high-barriers patients, the intervention significantly increased vaccination acceptance. Among low-barriers patients, the intervention did not influence vaccination acceptance.

CONCLUSIONS

The self-prediction intervention significantly increased vaccination acceptance among "high-barriers" patients, who typically have very low vaccination rates. This brief intervention could be a useful tool in increasing vaccine uptake among high-barriers patients.