Short-term and long-term behavioral effects of vaccination mandates.

Current COVID-19 vaccination levels are insufficient to achieve herd immunity. To implement effective interventions toward ending the pandemic, it is essential to understand why people are motivated and willing to receive vaccination. The study aims to evaluate attitudes toward COVID-19 vaccination mandates and the impact of policies on future vaccine uptake and behavior utilizing self-determination theory. We conducted an online survey (n = 569) in the U.S. and Turkey to investigate a relationship between respondents' psychological needs and their willingness and motivation to receive COVID vaccination. The study examined the possible impact of vaccine mandates on these needs. Autonomy satisfaction was the leading predictor of willingness to receive vaccination (p < .0001). Relatedness satisfaction was the leading predictor of one's intention to receive vaccination (OR = 3.382; p = .0001). The strongest positive correlation was found between needs frustration and external motivation. A moderate positive correlation was found between competence frustration and introjected motivation. No association was found between vaccine mandates and psychological needs. Need satisfaction, especially autonomy and relatedness, appear to positively influence willingness and intention to receive a vaccination. On the other hand, need frustration, especially autonomy and competence frustration, correlates with external motivation, thereby suggesting a detrimental long-term effect on vaccination behavior. Need satisfaction promotes positive vaccination behavior, while need frustration might adversely affect motivation and willingness to receive vaccination. Strategies promoting autonomous decision-making might be more effective than vaccination enforcement in sustaining positive vaccination behavior.

Viral Respiratory Epidemic Modeling of Societal Segregation Based on Vaccination Status.

BACKGROUND: Societal segregation of unvaccinated people from public spaces has been a novel and controversial coronavirus disease 2019 (COVID-19)-era public health practice in many countries. Models exploring potential consequences of vaccination-status-based segregation have not considered how segregation influences the contact frequencies in the segregated groups. We systematically investigate implementing effects of segregation on population-specific contact frequencies and show this critically determines the predicted epidemiological outcomes, focusing on the attack rates in the vaccinated and unvaccinated populations and the share of infections among vaccinated people that were due to contacts with infectious unvaccinated people. METHODS: We describe a susceptible-infectious-recovered (SIR) two-population model for vaccinated and unvaccinated groups of individuals that transmit an infectious disease by person-to-person contact. The degree of segregation of the two groups, ranging from zero to complete segregation, is implemented using the like-to-like mixing approach developed for sexually transmitted diseases, adapted for presumed severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) transmission. We allow the contact frequencies for individuals in the two groups to be different and depend, with variable strength, on the degree of segregation. RESULTS: Segregation can either increase or decrease the attack rate among the vaccinated, depending on the type of segregation (isolating or compounding), and the contagiousness of the disease. For diseases with low contagiousness, segregation can cause an attack rate in the vaccinated, which does not occur without segregation. INTERPRETATION: There is no predicted blanket epidemiological advantage to segregation, either for the vaccinated or the unvaccinated. Negative epidemiological consequences can occur for both groups.

The effect of moral appeals on influenza vaccination uptake and support for a vaccination mandate among health care workers.

OBJECTIVE: Influenza vaccination uptake among health care workers (HCWs) protects patients and staff. Still, many health institutions' coverage rates are unsatisfactory. We aimed to test the effect of communicating moral appeals in increasing vaccination uptake in a real life setting. METHOD: In three field experiments among HCWs, a moral appeal highlighting morally relevant consequences of influenza vaccination was manipulated. The outcome variables were vaccination intention right after exposure to the moral appeal (Study 1; N = 569 US and UK HCWs from various institutions) and vaccination uptake in subsequent weeks for those respondents who consented in sharing this data during the survey (Studies 2 and 3, respectively N = 121 and N = 770 Dutch hospital employees). RESULTS: Studies 1 and 3 showed that moral appeal enhanced vaccination intention and uptake (vaccination uptake increased by 11%), due to increased awareness that vaccination is a moral decision. In Study 2, moral appeal had no effect, probably because people with more outspoken vaccination attitudes had responded to the call to fill in the survey. Moreover, moral appeal increased support for an influenza vaccination mandate. Furthermore, the results suggest that moral appeal was especially effective among HCWs with no history of influenza vaccination. CONCLUSION: These results indicate that moral appeal can be a useful tool for increasing both vaccination uptake and mandate support within health care institutions.

Barriers and facilitators to influenza vaccination and vaccine coverage in a cohort of health care personnel.

BACKGROUND: Annual influenza vaccination is recommended for health care personnel (HCP). We describe influenza vaccination coverage among HCP during the 2010-2011 season and present reported facilitators of and barriers to vaccination. METHODS: We enrolled HCP 18 to 65 years of age, working full time, with direct patient contact. Participants completed an Internet-based survey at enrollment and the end of influenza season. In addition to self-reported data, we collected information about the 2010-2011 influenza vaccine from electronic employee health and medical records. RESULTS: Vaccination coverage was 77% (1,307/1,701). Factors associated with higher vaccination coverage include older age, being married or partnered, working as a physician or dentist, prior history of influenza vaccination, more years in patient care, and higher job satisfaction. Personal protection was reported as the most important reason for vaccination followed closely by convenience, protection of patients, and protection of family and friends. Concerns about perceived vaccine safety and effectiveness and low perceived susceptibility to influenza were the most commonly reported barriers to vaccination. About half of the unvaccinated HCP said they would have been vaccinated if required by their employer. CONCLUSION: Influenza vaccination in this cohort was relatively high but still fell short of the recommended target of 90% coverage for HCP. Addressing concerns about vaccine safety and effectiveness are possible areas for future education or intervention to improve coverage among HCP.