Pre-deployment vaccinations and perception of risk among US military personnel

Abstract

IntroductionAlthough vaccination programs in the general population have dramatically reduced morbidity and mortality associated with certain infectious diseases, public attitudes toward immunization programs have at times been contentious. 1 For example, in the past decade, research linking the onset of autism to receipt of the measles-mumps-rubella (MMR) vaccine has reduced vaccination rates for children in the US and Europe, leading to outbreaks of preventable disease.2,3 The human papillomavirus (HPV) vaccine has not gained widespread acceptance for girls and young women due, in part, to the social implications of sexual promiscuity or increased risky behavior as well as unrealized safety concerns. 4,5 By early 2010, only approximately 25% of the US population had received the influenza A(H1N1) vaccine despite strong recommendations for the majority of the population by the Centers for Disease Control and Prevention.6 A lack of a perceived disease risk as well as concerns over vaccine safety and efficacy are thought to be the drivers behind the sub-optimal vaccination rates. [7][8][9] Vaccine safety concerns and relatively low vaccination Background: Vaccination programs have significantly reduced the incidence of numerous infectious diseases; however, public attitudes toward immunization oftentimes remain contentious. concerns over vaccine safety and effectiveness, compounded with reduced perceived risk of disease, influence decision making and frequently override public health recommendations. although vaccinations are compulsory for Us military personnel, their concerns mirror the general population, resulting in sub-optimal coverage. Results: Demographics of the 1,757 respondents: 83.3% male, 71.1% army, 87.5% enlisted, mean age of 29.2 years (standard deviation: 8.3). The majority (89.3%) reported receiving all pre-deployment vaccines; 17.1% stated they would decline if given the opportunity. Factors associated with an increased likelihood of declining vaccines included a perception that the vaccines were not safe [odds ratio (OR): 3.7; p < 0.001] and rarely/never believing information from the military command (OR: 2.2; p < 0.001). Those with a perceived risk for the diseases targeted by the vaccines were less likely to decline (OR: 0.6; p < 0.001).Discussion: In Us military personnel, negative perceptions of pre-deployment vaccines exist. These attitudes appear to be associated with negative perceptions of vaccine safety and low perceived disease risk. Targeted interventions, focusing on the drivers of negative perceptions toward vaccines, and accounting for the source of the educational material, may influence attitudes and improve vaccination perceptions.Methods: a self-administered questionnaire was completed by a convenience sample of Us military personnel deployed to Iraq, afghanistan and surrounding regions. Questions solicited demographic information and assessed agreement with statements in an attempt to identify factors associated with declining pre-deployment vaccines.

Willingness to receive a hypothetical avian influenza vaccine among US military personnel in mid-deployment

“…Discussion This study supports prior findings indicating that vaccine safety and disease risk are important factors in hypothetical vaccination compliance among military populations despite the compulsory nature of vaccines in this population. 8 Furthermore, despite both factors being associated with an increased willingness to receive the hypothetical vaccine, the "Vaccine" factor showed the greatest strength of association highlighting the importance of perceived vaccine safety and efficacy regardless of perceived disease risk.…”

“…Most recently, Polak et al noted that among a deployed force, 17.1% of respondents would decline vaccinations if given the opportunity; an observation that was associated with concerns of vaccine safety and low perceived disease risk. 8 Similarly, when focusing on anthrax vaccine uptake in military personnel, the lone factor significantly associated with vaccination rejection was perceived vaccine safety. 13 While neither those studies nor this one likely capture all elements inherent in the decision factors, they clearly point to two main themes as areas for potential targeted education for existing and future vaccines.…”

“…This proportion is higher than what has been reported in a prior study in this population and may be the result of central tendency bias or respondents unwillingness to state disagreement with a willingness to receive a vaccine in a compulsory environment. 8 Other limitations are inherent in exploratory factor analysis including the identification of the number of factors. Some have argued that the Kaiser method of factor retention overestimates the number of factors that should be retained and does not account for the fact that some eigenvalues may fall just above or below one.…”

“…[1][2][3] Nonetheless, vaccination rates for many vaccine-preventable diseases are sub-optimal and the factors driving these suboptimal rates are poorly understood. [4][5][6][7][8][9][10][11] Understanding the factors associated with sub-optimal vaccination rates may enable targeted education efforts to minimize those factors and improve vaccine coverage and subsequently lower disease incidence.…”

“…Prior studies in this population have identified a poor understanding of disease risk and severity as well as concerns over vaccine safety as key components in sub-optimal predeployment vaccination rates despite receipt requirements. 8,9,12,13 Interestingly, research thus far has focused on currently available vaccines without an eye toward the development of novel vaccine candidates that may become available in the near future. A vaccine against H5N1 is one such candidate that may be recommended for a subset of service members deploying to at risk regions.…”