Pre-event willingness to receive smallpox vaccine among physicians and public safety personnel.

Background: Planning for voluntary smallpox vaccination of health and safety officials began in December 2002.

Materials And Methods: Surveys were conducted among physicians and fire and police department personnel in Atlanta, Georgia. Information on demographics, willingness to receive smallpox vaccine, self-reported knowledge level, and potential vaccine contraindications was analyzed.

Results: Forty-one percent of physicians (n = 199) were undecided on vaccination (32% would receive vaccine and 27% would not). Forty-eight percent of firefighters (n = 343) and 41% of police (n = 466) were undecided; 23% and 41% would receive vaccine, whereas 28% and 18% would not (fire and police, respectively). Absence of contraindications was associated with physicians' willingness to be vaccinated (P = 0.006). Many physicians (66%) and most public safety personnel (88%) considered themselves inadequately informed on smallpox vaccine. In a multivariate analysis, inadequately informed respondents were more likely to be undecided (OR = 2.23, CI = 1.39 to 3.56).

Conclusions: Before implementation of the smallpox vaccination program, self-assessed knowledge about smallpox disease and vaccine were poor.

Key Words: smallpox, vaccination, willingness, acceptance, training

**********

Efforts to prepare for biological terrorism in the United States included considerable attention to smallpox and smallpox vaccination policy in 2002 and 2003. (1,2) Decision-makers disputed the benefits of vaccination against the rare but known serious adverse reactions to the vaccine. Questions about the timing and dosage of vaccination, the populations in which to offer vaccine, and the risk of a national smallpox vaccination program were debated. As a result, various strategies to address the threat of smallpox were proposed by many individuals, including scientists, statisticians, and clinicians, (3-8) but consensus was not reached before the initial phases of the program were rapidly implemented.

At the federal level, progress toward a smallpox vaccination policy began to emerge in October 2002, when the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention recommended voluntary smallpox vaccination of healthcare workers serving on Smallpox Public Health Response Teams and Smallpox Health Care Teams. (9) On December 13, President Bush formally announced his administration's plans for smallpox vaccination; he endorsed the ACIP recommendations and called for voluntary vaccination of emergency healthcare workers forming Smallpox Response Teams and military and civilian personnel in high threat areas. (10) At that time, it was also understood that the President planned for subsequent vaccination of as many as 10 million first responders, including members of fire and police departments. (11,12)

To assess willingness to be vaccinated against smallpox and self-reported knowledge about the vaccine and disease, we performed surveys among physicians at Emory University in Atlanta, Georgia, whose specialty was included in the ACIP recommendations and among police and fire department personnel in the same metropolitan area. We also estimated the prevalence of potential vaccine contraindications.

Materials and Methods

We developed a voluntary, anonymous survey instrument to assess willingness to accept smallpox vaccination. The questionnaire included three sections: (1) nonidentifying demographic and employment information (eg, sex, age, household size, function and level in organization). (2) perceived knowledge regarding smallpox disease and vaccine (on a four-point scale), and (3) questions about potential vaccine contraindications in recipients and household members of vaccine recipients (listed in Table 1).

Among healthcare providers, survey data were collected by convenience sampling during gatherings of physicians, including medical grand rounds or specialty conferences, between November 22 and December 17, 2002 (93% before President Bush's program announcement). Physicians who specialized in internal medicine, emergency care, infectious diseases, and pulmonary/critical care and who practiced at four hospitals affiliated with Emory University in Atlanta, Georgia were included. In February 2003, explanatory letters were sent to approximately 1,700 DeKalb County public safety officials (fire and rescue personnel and police officers) who were requested to complete enclosed surveys for return to their supervisors.

The studies were approved by Emory University's Institutional Review Board. Data entry quality was verified by re-entry of every tenth record and subsequently analyzed in SAS version 8.02 for Windows (SAS Institute Inc, Cary, NC). [chi square] and Fisher exact tests of significance are reported as appropriate. Polytomous logistic regression, comparing unwilling and undecided respondents with those willing to receive vaccine, was used to calculate adjusted "odds-like ratios" (ORs) and 95% confidence intervals (CIs). (13) Modeling was performed in SAS via PROC CATMOD and backward elimination; the initial model included age, sex, household size, any contraindication, vaccine knowledge level, and type of respondent (physician, fire, or police) and five two-way interactions (age and sex, household size and any contraindication, household size and respondent type, any contraindication and respondent type, and knowledge level and respondent type). Vaccine knowledge level was examined as an ordinal and dichotomous predictor.

Results

Two hundred twenty-six physician surveys were completed; after eliminating 24 nonphysicians and 3 respondents for whom willingness to accept vaccine was not indicated, the final physician cohort consisted of 79 faculty, 108 residents in training, and 12 for whom level of training was not ascertained (n = 199). The surveys of public safety personnel who responded within 1 week and included data on willingness to accept the vaccine were analyzed (n = 809).

Among physicians who indicated a specialty (97%), internal medicine practitioners comprised the largest group (45%), followed by emergency medicine (30%), infectious diseases (14%), and pulmonary/critical care specialists (10%). Forty-one percent were under 30 years of age and 39% were between the ages of 30 and 44; 61% percent of this older age group stated that they had received the smallpox vaccine in the past. All but three physicians over the age of 45 years (92%) reported previously receiving the vaccine. Among public safety personnel, 58% were police and 80% were 30 years of age or older. This group included 11% women and a greater proportion with past military service (32%) compared with civilians 18 and older in the United States (13%). (14) Seventy-eight percent of firefighters were licensed emergency medical technicians.

Willingness to accept smallpox vaccination differed in the three groups of respondents (P < 0.001). When asked if they were willing to receive smallpox vaccine if it was offered today, 32% of physicians surveyed answered yes, 27% answered no, and 41% were undecided. Twenty-three percent of firefighters and 41% of police indicated willingness to accept smallpox vaccine, 28% of firefighters and 18% of police were unwilling, and 48% of firefighters and 41% of police were undecided. Among the small group of physicians over the age of 60 years, 58% were willing to be vaccinated, whereas 30% of physicians under 60 years were willing (P = 0.05) (Table 2). Firefighters under 30 years of age indicated willingness to be vaccinated more often than their counterparts over 30 years (P = 0.01); willingness to be vaccinated did not differ between physician respondents under 30 years of age and their older counterparts (P = 0.53) or among police under 30 years and their older counterparts (P = 0.15). Past vaccination was not associated with willingness to be revaccinated in physicians or either public safety group.

At the time of the surveys, self-assessed knowledge about smallpox disease and vaccine were poor in both groups; 51% of physicians stated they were inadequately informed (not informed or only somewhat informed) about the disease and 66% stated that they were inadequately informed about the vaccine. Among public safety personnel, more than four fifths indicated they were inadequately informed about the disease (85%) and the vaccine (88%). Physicians who considered themselves adequately informed about disease (very well informed or well informed), also felt adequately informed about the vaccine [Pearson correlation coefficient (p) = 0.83, P < 0.0001]. Although the correlation between self-assessed knowledge of smallpox disease and vaccine was not as marked in public safety personnel, it was also significant (p = 0.44, P < 0.0001).

Significant differences in vaccination willingness were not found between the four physician specialties (P = 0.38) or between faculty and residents (P = 0.14). Self-reported knowledge about the vaccine was highest among infectious diseases specialists (75%) and differed significantly from the combined knowledge level of other specialties (27%) (P < 0.001). Physicians who felt inadequately informed about the smallpox vaccine were more likely to be undecided (P < 0.001).

Firefighters who reported they were inadequately informed about the smallpox vaccine were also more likely to be undecided (P < 0.001), but vaccine knowledge level did not relate strongly to overall decidedness in police (P = 0.06). Firefighter willingness to be vaccinated did not differ on the basis of previous military service or emergency medical technician licensure (P = 0.24 and P = 0.64, respectively), but veterans in the police department more often indicated willingness to receive vaccine than police without former military service (P = 0.005).

The overall prevalences of any contraindication, in vaccine recipients or their households, were 39% in physicians and 27% in both public safety groups. The prevalences of one or more of the self-reported smallpox vaccine contraindications were 25%, 15%, and 14% for physicians, firefighters, and police, respectively (Table 1). Prevalences of any contraindication in household members of the three groups were 26%, 18%, and 18%, respectively. Contraindications related to eye diseases of the conjunctiva or cornea were rare, whereas dermatological contraindications (history of eczema or other chronic skin disease) were reported in 20% of physicians, 11% of public safety officials, 22% of physicians' household members, and 15% of public safety officials' household members. The absence of contraindications in both the vaccine recipient and their household members was strongly associated with willingness to accept smallpox vaccine in physicians (P = 0.006) but not public safety officials.

Of 397 respondents who selected one or more reasons for being unwilling or undecided on receipt of the smallpox vaccine, approximately three fourths (76%) cited concern for adverse reactions in themselves (Table 3). Concern for adverse reactions in the family was also commonly cited (40%), particularly among undecided firefighters (52%). Half of physicians who were not willing to receive vaccine cited the perception of smallpox risk as minimal (49%). In an open-ended question, 12 of 33 physicians (36%) and 11 of 63 public safety personnel (17%) added past vaccination as a reason for unwillingness or undecidedness to receive the vaccine (eg, "received vaccine as a child," "possibly vaccinated previously").

In multivariate analyses, controlling for age, sex, and presence of any contraindication, only the interaction of household size and type of respondent retained significance (P = 0.02). Significant differences between persons who were undecided on receiving vaccine and persons who were willing to receive vaccine were found. Police respondents who were undecided on vaccination were 2.1 times more likely (CI = 1.13 to 2.86) to reside in households with two or more other individuals relative to police living alone. Respondents who considered themselves not informed, somewhat informed, and well informed were, respectively, 5.15 times (CI = 2.57 to 10.33), 2.98 times (CI = 1.88 to 4.74), and 1.73 times (CI = 1.37 to 2.18) more likely to be undecided compared with very well-informed respondents. Similarly, inadequately informed individuals were 2.23 times more likely to be undecided (CI = 13.9 to 3.56) compared with more informed individuals. Significant differences between persons unwilling and willing to receive vaccine were not found.

Discussion

In December 2002, the Bush Administration, through the Department of Health and Human Services, announced plans for voluntary, pre-event smallpox vaccination of hospital-based healthcare workers and subsequent vaccination of first responders. The program itself and its rapid implementation have generated considerable controversy over the risk-benefit ratio. (15,16) Among civilians, 39,213 healthcare and public health professionals received the vaccine, (17) which was 7.8% of the original goal (500,000 vaccinations). A total of 21 probable or suspected cases of myocarditis or pericarditis associated with smallpox vaccination were reported; an additional 97 serious adverse events, including deaths, "temporally associated with vaccination but not necessarily causally associated with vaccination" were also reported. (17) A 7.5-fold greater than expected incidence of myopericarditis (16.11/100,000) was reported among 347,516 primary vaccinees in the US Armed Forces. (18) An analysis of New York City death certificate data before, during, and after its April 1947 mass smallpox vaccination campaign of 6.35 million people did not suggest increased cardiac mortality after the campaign. (19)

Before potential adverse cardiac events were detected and publicized, (20) we found that 32% of physicians surveyed indicated willingness to receive smallpox vaccine and 41% were undecided. In separate surveys, 23% percent of fire-fighters and 41% of police in the same metropolitan area also indicated willingness to accept smallpox vaccine, whereas 48% of firefighters and 41% of police were undecided. Respondents with lower perceived vaccine knowledge were more likely to be undecided on whether to receive vaccine.

Other explanations may have also contributed to a minority of respondents reporting willingness to receive smallpox vaccine. In all respondent groups, concern for adverse reactions in oneself was a commonly cited reason for undecidedness or unwillingness to be vaccinated. Indeed, severe reactions, though rare, are more frequent after smallpox vaccination than after any routinely administered vaccine. (21,22) Among physicians, 31% who were not willing to be vaccinated reported potential vaccine contraindications, and almost half who were undecided reported potential contraindications (49%). Overall, self-reporting of one or more vaccine contraindications was common in physicians (39%). A similar prevalence of contraindications (37%) was reported with provisional data on screening of 278 US military personnel in December of 2002. (23) Kemper et al (24) estimated that medical self-exclusion from smallpox vaccine might be lower (25%) in the context of a mass smallpox vaccination campaign of the public. Police and fire and rescue personnel, who may be less aware of potential contraindications, reported lower prevalences of contraindications than physicians (28% and 27%, respectively). Police department personnel in larger households were more likely to indicate undecidedness on vaccination, possibly reflecting concern for children in their households.

Several national surveys of emergency department (ED) and intensive care workers' willingness to receive smallpox vaccine have been published (25-28) but none among physicians of other specialties or public safety personnel. In two such surveys, ED workers reported greater willingness to be vaccinated (relative to our findings) and frequently either perceived the 2-year risk of a smallpox attack to be intermediate or high (53%) (25) or cited self-protection as the primary reason for desiring smallpox vaccination (72%). (26) Yih et al (25) targeted member hospitals of the Centers for Disease Control and Prevention Epicenters or Duke Infection Control Outreach Network and found that 61% of respondents indicated they would "probably or definitely" be vaccinated, and more than half thought a smallpox attack within 2 years was of intermediate or high risk. Everett and colleagues, (26) who identified academic EDs in the 10 most populous cities, found that almost three quarters of ED personnel would receive smallpox vaccine, and respondents commonly cited a desire for self-protection as a rationale, often despite potential contraindications. A third national survey, which recruited respondents through the Society for Academic Emergency Medicine and the EMERGEncy Infectious Diseases Net surveillance group, had findings that were consistent with the present survey. (28) Forty-three percent of respondents reported willingness to receive vaccine, and 56% perceived the threat of a bioterror attack with smallpox as large or likely. Notably, physician respondents in our survey were affiliated with a medical center, which, immediately after the survey, gained early national attention for its cautious approach to the smallpox vaccination program (29); half of physicians we surveyed who were not willing to receive vaccine perceived smallpox risk as minimal (49%).

There has been concern for potential transmission of vaccinia among household members as well as among patients of workers (30,31); many patients today are immunocompromised. (32) Cautioning that there might be a higher incidence of contact vaccinia (as compared with the 1960s experience), Neff and colleagues (33) noted that almost all persons under age 30 years have no vaccinia immunity and would be primary vaccinees (shedding virus from the vaccination site for up to 19 days) and that an unknown but high percentage of persons over age 30 might also react like primary vaccinees and shed virus because they may have had only a single vaccination in childhood. (34) These transmission events were rare. Among 508,546 vaccinated military personnel, 30 cases of suspected contact transfer of vaccinia to 12 spouses, 8 adult intimate contacts, 8 adult friends, and 2 children in the same household were identified though passive surveillance (vaccinia was laboratory-confirmed in 18 of 30; 2 of the 18 resulted from tertiary transmission). (35) Nosocomial spread of vaccinia during the 2002 to 2004 vaccinations was not documented, including among 27,700 Department of Defense workers, where no vaccinia transmission from vaccinated workers to unvaccinated patients was identified (nor from vaccinated patients to unvaccinated worker). (35)

Past vaccination was not associated with willingness to be vaccinated in our surveys, despite data indicating that complications are more common among primary vaccinees. (21) As compared with persons revaccinated, primary vaccinees had a 10-fold greater risk of eczema vaccinatum (approximately 1 case per 100,000), a 20-fold greater risk of generalized vaccinia (approximately 2 cases per 100,000), and, whereas there were no cases of postvaccinial encephalitis among revaccinees, the risk was approximately 3 cases per million among primary vaccinees. Respondents' comments that past vaccination was a reason for unwillingness to be revaccinated also suggests that some may not be aware of the decline in immunity to smallpox 5 to 10 years after primary vaccination. (36)

These self-reported data should be interpreted while considering several limitations. Additional potential contraindications for vaccine recipients or their household members (eg, history of cardiovascular disease) emerged after we conducted the surveys. (20,37) As a result, the prevalences of vaccine contraindications herein may be underestimates of true potential contraindications. Respondents in metropolitan Atlanta are not representative of all physicians, fire and rescue personnel, or police in the United States. Physician respondents and their colleagues are proximal to public health specialists, particularly experts from the global smallpox eradication program in the 1960s and 1970s who favored a "no vaccine" position toward the program in 2003. This stance may have influenced the vaccine policy for the state of Georgia; as of September 30, 2004, 2.0 vaccines were administered per 100,000 persons in Georgia compared with 13.6 per 100,000 persons nationally and 11.2, 23.7, and 24.1 per 100,000 in neighboring Alabama, Florida, and South Carolina, respectively (US Census, 2003). (38)

Our surveys demonstrated that a large number of respondents were undecided as to whether they would participate in vaccination against smallpox. Those who considered themselves more informed were most likely to state whether they would participate; those who felt inadequately informed were more likely to be undecided. This suggests that considerable education of potential vaccinees would be needed regardless of their ultimate decision.

The reluctance of physicians and public safety officials to be immunized is not surprising. Self-reported knowledge about the disease and the vaccine were low, many respondents reported potential contraindications, and the risk-benefit ratio was unclear. In fact, the benefits of smallpox vaccination programs continue to be vigorously debated. (15,16) Future smallpox preparedness activities should capitalize on lessons learned from the 2003 smallpox pre-event and other vaccination programs. (39,40) Work will be needed to establish consensus policies among different types of stakeholders with varying perspectives (41) and to educate and address concerns among potential volunteer vaccinees.

Acknowledgments

This work was made possible through the support of the O. Wayne Rollins Foundation and the participation of physicians affiliated with the Emory School of Medicine and members of the police and fire departments of DeKalb County, Georgia. We thank C. Christina Bahn and Colleen Spellen for their support.

References

1. Henderson DA, Inglesby TV, Bartlett JG, et al. Smallpox as a biological weapon: medical and public health management. JAMA 1999;281:2127-2137.

2. Cohen J, Enserink M. Rough-and-tumble behind Bush's smallpox policy. Science 2002;298:2312-2316.

3. Meltzer MI, Damon I, LeDuc JW, et al. Modeling potential responses to smallpox as a bioterrorist weapon. Emerg Infect Dis 2001;7:959-969.

4. Kaplan EH, Craft DL, Wein LM. Emergency response to a smallpox attack: the case for mass vaccination. Proc Natl Acad Sci U S A 2002;99:10935-10940.

5. Halloran ME, Longini IM, Nizam A, et al. Possible containment of bioterrorist smallpox. Science 2002;298:1428-1432.

6. Epstein JM, Cummings DAT, Chakravarty S, et al. Toward a containment strategy for smallpox bioterror: An individual-based computational approach. Available at: http://www.brook.edu/dybdocroot/es/dynamics/papers/bioterrorism.pdf. Accessed November 11, 2004.

7. Bozzette SA, Boer R, Bhatnagar V, et al. A model for a smallpox-vaccination policy. N Engl J Med 2003;348:416-425.

8. Mack T, A different view of smallpox and vaccination. N Engl J Med 2003;348:460-463.

9. Advisory Committee on Immunization. Practices (ACIP). Summary of October 2002 ACIP Smallpox Vaccination Recommendations. Available at: http://www.bt.cdc.gov/agent/smallpox/vaccination/acip-recs-oct2002. asp. Accessed November 20, 2002.

10. The White House. Protecting Americans: Smallpox Vaccination Program. Available at: http://www.whitehouse.gov/news/releases/2002/12/20021213-1.html. Accessed December 13, 2002.

11. Cable News Network. Source: Bush to announce plan for smallpox vaccinations. Available at: http://archives.cnn.com/2002/HEALTH/conditions/11/26/smallpox.vaccine/. Accessed October 15, 2004.

12. Institute of Medicine. Review of the Centers for Disease and Prevention's Smallpox Vaccination Program Implementation: Letter Report #1. Available at: http://www.iom.edu/project.asp?id=4781. Accessed December 29, 2004.

13. Kleinbaum DG. Klein M., In: Logisitie Regression: A Self-Learning Text. 2nd ed. New York, NY: Springer; 2002.

14. US Department of Veterans Affairs. Census 2000 Veteran Data. Available at: http://www.va.gov/vetdata/Census2000/. Accessed November 3, 2004.

15. Cohen HW, Gould RM, Sidel VW. The pitfalls of bioterrorism preparedness: the anthrax and smallpox experiences. Am J Public Health 2004;94:1667-1671.

16. Weiss MM. Weiss PD, Mathisen G, et al. Rethinking smallpox. Clin Infect. Dis 2004;39:1668-1673.

17. Centers for Disease Control and Prevention. Update: Adverse events following civilian smallpox vaccination: United States, 2003. Morb Mortal Wkly Rep 2004;53:106-107.

18. Arness MK. Eckart RE. Love SS, et al. Myopericarditis following smallpox vaccination. Am J Epidemiol 2004;160:642-651.

19. Thorpe LE, Mostashari F, Karpati AD, et al. Mass smallpox vaccination and cardiac deaths. New York City, 1947. Emerg Infect Dis 2004;10:917-920.

20. Centers for Disease Control and Prevention. Temporary deferral recommended for heart patients volunteering for smallpox vaccination. Available at: http://www.cdc.gov/od/oc/media/pressrel/r030325.htm. Accessed November 12, 2004.

21. Lane JM, Ruben FL, Neff JM, et al. Complications of smallpox vaccination, 1968; national surveillance in the United States. N Engl J Med 1969;281:1201-1208.

22. Maldonado YA. Current controversies in vaccination: vaccine safety. JAMA 2002;288:3155-3158.

23. Knox R. US military smallpox vax experience [NPR edited text]. Available at: http://www.fas.org/promed/. Accessed January 11, 2003 (ProMED archive no. 20021222.6113).

24. Kemper AR, Davis MM, Freed GL. Expected adverse events in a mass smallpox vaccination campaign. Effective Clin Pract 2002;5:84-90.

25. Yih WK, Lieu TA, Rego VH, et al. Attitudes of healthcare workers in US hospitals regarding smallpox vaccination. BMC Public Health 2003;3:20.

26. Everett WW. Coffin SE, Zaoutis T, et al. Smallpox vaccination: a national survey of emergency health care providers. Acad Emerg Med 2003;10:606-611.

27. Everett WW, ZT, Halpern SD, Strom BL, Coffin SE. Preevent vaccination against smallpox: a survey of pediatric emergency health care providers. Pediatr Infect Dis J 2004;23:332-337.

28. Kwon N, Raven MC, Chiang WK, et al. Emergency physicians' perspectives on smallpox vaccination. Acad Emerg Med 2003;10:599-605.

29. Gettleman J. Two hospitals refuse to join Bush's plan for smallpox. New York Times 2002. Available at: http://query.nytimes.com/gst/abstract.html?res=F60C13FC3B590C7A8DDDAB0994DA404482. Accessed November 19, 2004.

30. Cherry JD, Risks to children of health care personnel receiving smallpox vaccination Pediatr Infect Dis J 2003;22:574-574.

31. Sepkowitz KA. How contagious is vaccinia? N Engl J Med 2003;348:439-446.

32. Amorosa VK, Isaacs SN. Separate worlds set to collide: smallpox, vaccinia virus vaccination, and human immunodeficiency virus and acquired immunodeficiency syndrome. Clin Infect Dis 2003;37:426-432.

33. Cooney EL, Collier AC, Greenberg PD, et al. Safety of and immunological response to a recombinant vaccinia virus vaccine expressing HIV envelope glycoprotein. Lancet 1991;337:567-572.

34. Neff JM, LJ, Fulginiti VA, Henderson DA. Contact vaccinia: transmission of vaccinia from smallpox vaccination. JAMA 2002;288:1901-1905.

35. Centers for Disease Control and Prevention. Secondary and tertiary transfer of vaccinia virus among US military personnel: United States and worldwide. 2002-2004. Morb Mortal Wkly Rep 2004;53:103-105.

36. Breman JG, Henderson DA. Diagnosis and management of smallpox. N Engl J Med 2002;346:1300-1308.

37. Centers for Disease Control and Prevention. Smallpox vaccination and adverse reactions guidance for clinicians. MMWR Recomm Rep 2003;52:1-32.

38. Centers for Disease Control and Prevention. Smallpox vaccimation program status by state. Available at: http://www.cdc.gov/od/oc/media/spvaccin.htm. Accessed November 12, 2004.

39. Ching P. Tynan WP, Raymond D, et al. Hospital recruitment for the smallpox pre-event vaccination program: experiences from Florida. Nebraska. New Jersey, and Tennessee. December 2002-June 2003. Public Health Rep 2004;119:552-556.

40. Institute of Medicine. The smallpox vaccination program public health in an age of terrorism. Washington, DC: National Academies Press; 2005.

41. Aragon TJ, Fernyak SE. The risks and benefits of pre-event smallpox vaccination: where you stand depends on where you sit. Ann Emerg Med 2003;42:681-684.

Benjamin J. Silk, MPH, Carlos del Rio, MD, FACP, Lillian K. Ivansco, MPH, Scott F. Wetterhall, MD, MPH, James J. Augustine, MD, Henry M. Blumberg, MD, and Ruth L. Berkelman, MD

From the Center for Public Health Preparedness and Research and the Department of Epidemiology, Rollins School of Public Health, Emory University; the Department of Medicine, the Division of Infections Diseases, and the Department of Emergency Medicine, Emory University School of Medicine; and the Public Health Systems and Security Research Program, RTI International, Atlanta, GA.

Reprint requests to Benjamin J. Silk, MPH, Center for Public Health Preparedness and Research, 1518 Clifton Road NE, Atlanta, GA 30317. Email: [e-mail]

Accepted May 10, 2005.

RELATED ARTICLE: Key Points

* Willingness to receive smallpox vaccine differed significantly among physicians (32%), firefighters (23%), and police (41%), but all three respondent types were frequently undecided (44%).

* Physicians indicated a contraindication to the vaccine in themselves or a household member more often than public safety personnel (39% vs 27%).

* The absence of any contraindication was associated with willingness to be vaccinated in physicians but not public safety personnel.

* Many physicians (66%) and most public safety personnel (88%) considered themselves to be inadequately informed on smallpox vaccine.

* Respondents who were undecided on receiving vaccine were more than twice as likely to report inadequate knowledge of smallpox vaccine when compared with those who were willing to receive vaccine (OR = 2.23).

Table 1. Self-reported prevalences of potential smallpox vaccine
contraindications in vaccine recipients and members of their
households (a)

                                      Physicians  Fire/rescue  Police
                                      (n = 199)   (n = 343)    (n = 466)

History of eczema in recipient        21 (11)     20 (6)        24 (5)
History of eczema in household        22 (11)     35 (10)       39 (8)
History of chronic skin condition in  19 (10)     18 (5)        31 (7)
  recipient (b)
History of chronic skin condition in  21 (11)     17 (5)        29 (6)
  household (b)
Immunosuppression in recipient (c)    10 (5)      10 (3)         7 (2)
Immunosuppression in household (c)    12 (6)       9 (3)        17 (4)
Eye disease of conjunctiva/cornea in   5 (3)       1 (0)         1 (0)
  recipient
Eye disease of conjunctiva/cornea in   2 (1)       1 (0)         1 (0)
  household
Vaccine component allergy in           7 (4)       9 (3)         6 (1)
  recipient (c)
Any contraindication in recipients    49 (25)     51 (15)       63 (14)
Any contraindication in household     51 (26)     62 (18)       86 (18)
Any contraindication in recipients    78 (39)     95 (28)      124 (27)
  or household

(a) Number (prevalence percentage).
(b) Excluding eczema.
(c) Recent immunosuppressive therapy in the last month or condition that
might weaken immune system; allergy to polyntyxin B. streptomycin,
tetracycline, or neomycin.

Table 2. Factors associated with willingness to receive the smallpox
vaccine in physicians, fire and rescue personnel, and police (a)

                            Physicians (n = 199)
                       Yes      No       Undecided  P

All                    64 (32)  54 (27)  81 (41)
Age                                                 0.27
  Under 30 years       24 (30)  17 (21)  40 (49)
  30-44 years          24 (31)  22 (28)  32 (41)
  45-59 years           7 (27)  11 (42)   8 (31)
  60 years and above    7 (58)   4 (33)   1 (8)
Sex                                                 0.28
  Female               17 (26)  17 (26)  32 (48)
  Male                 36 (36)  26 (26)  37 (37)
No. in household                                    0.09
  Lives alone          17 (34)  12 (24)  21 (42)
  One other            19 (37)   8 (16)  24 (47)
  Two or more others   12 (24)  20 (40)  18 (36)
Informed, disease?                                  0.001
  Very well informed   11 (46)  10 (42)   3 (13)
  Well informed        30 (41)  23 (32)  20 (27)
  Somewhat informed    21 (23)  19 (21)  51 (56)
  Not informed          2 (20)   2 (20)   6 (60)
Informed, vaccine?                                  0.003
  Very well informed    8 (40)   9 (45)   3 (15)
  Well informed        20 (43)  16 (34)  11 (23)
  Somewhat informed    30 (30)  25 (25)  46 (46)
  Not informed          6 (21)   4 (14)  19 (66)
Had past vaccine?                                   0.13
  Yes                  30 (33)  30 (33)  31 (34)
  No                   33 (31)  23 (22)  49 (47)
Contraindication? (b)                               0.006
  Yes                  15 (19)  24 (31)  39 (50)
  No                   49 (41)  30 (25)  41 (34)

                            Fire/rescue (n = 343)
                       Yes      No        Undecided    P

All                    80 (23)  97 (28)   166 (48)
Age                                                    0.08
  Under 30 years       24 (36)  14 (21)    29 (43)
  30-44 years          42 (21)  62 (31)    97 (48)
  45-59 years          14 (19)  19 (26)    40 (55)
  60 years and above    0        2 (100)    0
Sex                                                    0.14
  Female               10 (26)  15 (39)    13 (34)
  Male                 66 (23)  77 (27)   145 (50)
No. in household                                       0.57
  Lives alone           9 (22)  13 (32)    19 (46)
  One other            14 (20)  17 (24)    40 (56)
  Two or more others   54 (25)  64 (29)   100 (46)
Informed, disease?                                     0.003
  Very well informed    5 (42)   4 (33)     3 (25)
  Well informed         9 (20)  22 (50)    13 (30)
  Somewhat informed    46 (25)  50 (27)    89 (48)
  Not informed         20 (20)  20 (20)    60 (60)
Informed, vaccine?                                   < 0.001
  Very well informed    4 (40)   3 (30)     3 (30)
  Well informed         5 (13)  24 (63)     9 (24)
  Somewhat informed    46 (25)  50 (27)    87 (48)
  Not informed         24 (22)  19 (17)    67 (61)
Had past vaccine?                                      0.57
  Yes                  32 (23)  39 (28)    67 (49)
  No                   35 (26)  43 (32)    57 (42)
Contraindication? (b)                                  0.09
  Yes                  19 (20)  35 (37)    41 (43)
  No                   61 (25)  62 (25)   125 (50)

                            Police (n = 466)
                       Yes       No       Undecided  P

All                    190 (41)  83 (18)  193 (41)
Age                                                  0.73
  Under 30 years        45 (47)  15 (16)   35 (37)
  30-44 years          112 (39)  53 (19)  119 (42)
  45-59 years           33 (39)  15 (18)   36 (43)
  60 years and above     0        0         1 (100)
Sex                                                  0.24
  Female                16 (33)  13 (27)   19 (40)
  Male                 162 (41)  69 (17)  168 (42)
No. in household                                     0.008
  Lives alone           43 (49)  19 (22)   26 (30)
  One other             51 (47)  24 (22)   34 (31)
  Two or more others    91 (37)  38 (15)  118 (48)
Informed, disease?                                   0.013
  Very well informed     8 (47)   6 (35)    3 (18)
  Well informed         24 (48)  10 (20)   16 (32)
  Somewhat informed    124 (44)  47 (17)  112 (40)
  Not informed          33 (29)  20 (18)   61 (54)
Informed, vaccine?                                   0.07
  Very well informed     4 (33)   5 (42)    3 (25)
  Well informed         17 (43)  10 (25)   13 (33)
  Somewhat informed    119 (43)  47 (17)  108 (39)
  Not informed          50 (36)  20 (14)   69 (50)
Had past vaccine?                                    0.12
  Yes                   73 (47)  25 (16)   56 (36)
  No                    70 (37)  43 (23)   75 (40)
Contraindication? (b)                                0.71
  Yes                   47 (38)  22 (18)   55 (44)
  No                   143 (42)  61 (18)  138 (40)

(a) Number (row percentage). As a result of rounding, percentages may
not sum to 100%. Persons 60 years and above excluded from significance
tests.
(b) Any contraindication in vaccine recipient or household member of
vaccine recipient (see Table 1 for any list of contraindications).

Table 3. Reasons for unwillingness and undecidedness on receipt of
smallpox vaccination in physicians, fire and rescue personnel, and
police (n = 397) (a)

                          Physicians (b)       Fire/rescue (c)
                       Unwilling  Undecided  Unwilling  Undecided
                       n = 47     n = 55     n = 83     n = 60

Concern for self       34 (72)    40 (73)    65 (78)    50 (83)
Concern for household  21 (45)    19 (35)    32 (39)    31 (52)
Concern for patients   14 (30)    11 (20)    --         --
Concern for others     --         --         17 (20)    15 (25)
Minimal smallpox risk  23 (49)    14 (25)    21 (25)     7 (12)

                           Police (c)
                       Unwilling  Undecided
                       n = 73     n = 79

Concern for self       55 (75)    59 (75)
Concern for household  24 (33)    31 (39)
Concern for patients   --         --
Concern for others      9 (12)     7 (9)
Minimal smallpox risk  14 (19)    13 (16)

(a) Number (percentage) among respondents who selected one or more
reasons for unwillingness or undecidedness to receive smallpox vaccine
from four reasons predesignated by the questionnaire.
(b) Physicians' choices (verbatim) were concern for adverse reactions in
me, concern for adverse reactions in family, concern for adverse
reactions in patients, and perceive smallpox risk as minimal. One or
more were permissible.
(c) Choices for public safety personnel (verbatim) were, concerned that
I will get sick from the vaccine, concerned that a family member will
get sick from being near me, concerned that someone else will get sick
from being near me, and do not think I am at risk of being exposed to
smallpox. One or more were permissible.