When vaccine misconceptions jeopardize public health

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Applied Evidence

When vaccine misconceptions jeopardize public health

J Fam Pract. 2014 December;63(12):E1-E7

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References

1. Zhou F, Shefer A, Wenger J, et al. Economic evaluation of the routine childhood immunization program in the United States, 2009. Pediatrics. 2014;133:577-585.

2. Centers for Disease Control and Prevention. Measles. Epidemiology and prevention of vaccine-preventable diseases. The Pink Book: Course Textbook. 12th ed. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/vaccines/pubs/pinkbook/meas.html. Accessed March 4, 2012.

3. Centers for Disease Control and Prevention. Measles (Rubeola). Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/measles/. Accessed November 19, 2014.

4. Measles. In: Pickering LK, Baker CJ, Kimberlin DW, et al, eds. Red Book: 2009 Report of the Committee on Infectious Diseases. 28th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2009:444-455.

5. Atkinson WL, Orenstein WA, Krugman S. The resurgence of measles in the United States, 1989-1990. Annu Rev Med. 1992;43:451-463.

6. Centers for Disease Control and Prevention (CDC). Measles--United States, 1990. MMWR Morb Mortal Wkly Rep. 1991;40:369-372.

7. Gindler J, Tinker S, Markowitz L, et al. Acute measles mortality in the United States, 1987-2002. J Infect Dis. 2004;189(suppl 1): S69-S77.

8. Centers for Disease Control and Prevention (CDC). Measles: United States, January-May 20, 2011. MMWR Morb Mortal Wkly Rep. 2011;60:666-668.

9. Bernstein DI, Reuman PD, Schiff GM. Rubeola (measles) and subacute sclerosing panencephalitis virus. In: Gorbach SL, Bartlett JG, Blacklow NR (eds). Infectious Diseases. Philadelphia, PA: WB Saunders; 1998:2135.

10. Bellini WJ, Rota JS, Lowe LE, et al. Subacute sclerosing panencephalitis: more cases of this fatal disease are prevented by measles immunization than was previously recognized. J Infect Dis. 2005;192:1686-1693.

11. Centers for Disease Control and Prevention (CDC). Progress toward elimination of Haemophilus influenza type b invasive disease among infants and children—United States, 1998-2000. MMWR Morb Mortal Wkly Rep. 2002;51:234-237.

12. Centers for Disease Control and Prevention (CDC). Epidemiology and Prevention of Vaccine-Preventable Diseases. The Pink Book, Course Textbook, 12th ed. Haemophilus influenzae type b. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/vaccines/pubs/pinkbook/hib.html. Accessed March 4, 2012.

13. Watt JP, Wolfson LJ, O’Brien KL, et al; Hib and Pneumococcal Global Burden of Disease Study Team. Burden of disease caused by Haemophilus influenzae type b in children younger than 5 years: global estimates. Lancet. 2009;374:903-911.

14. Agrawal A, Murphy TF. Haemophilus influenzae infections in the H. influenzae type b conjugate vaccine era. J Clin Microbiol. 2011;49:3728-3732.

15. Chandran A, Watt JP, Santosham M. Prevention of Haemophilus influenza type b disease: past successes and future challenges. Informa Healthcare. 2005;4:819-827.

16. Centers for Disease Control and Prevention (CDC). Invasive Haemophilus influenza Type B disease in five young children--Minnesota, 2008. MMWR Morb Mortal Wkly Rep. 2009;58:58-60.

17. McVernon J, Morgan P, Mallaghan C, et al. Outbreak of Haemophilus influenzae type b disease among fully vaccinated children in a day-care center. Pediatr Infect Dis J. 2004;23:38-41.

18. Hinman AR, Orenstein WA, Schuchat A; Centers for Disease Control and Prevention (CDC). Vaccine-preventable diseases, immunizations, and MMWR—1961-2011. MMWR Morb Mortal Wkly Rep. 2011;60 suppl 4:49-57.

19. Kempe A, Daley MF, McCauley MM, et al. Prevalence of parental concerns about childhood vaccines: the experience of primary care physicians. Am J Prev Med. 2011;40:548-555.

20. Godlee F, Smith J, Marcovitch H. Wakefield’s article linking MMR vaccine and autism was fraudulent. BMJ. 2011;342:c7452.

21. Institute for Vaccine Safety. Thimerosal content in some US Licensed vaccines. Institute for Vaccine Safety Web site. Available at: http://www.vaccinesafety.edu/thi-table.htm. Accessed March 8, 2012.

22. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention: Immunization safety and autism. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/vaccinesafety/00_pdf/CDCStudiesonVaccinesandAutism.pdf. Accessed September 23, 2013.

23. Centers for Disease Control and Prevention. Ensuring the safety of vaccines in the United States. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/vaccines/hcp/patient-ed/conversations/downloads/vacsafe-ensuring-color-office.pdf. Accessed November 18, 2014.

24. Wharton M. Vaccine safety: current systems and recent findings. Curr Opin Pediatr. 2010;22:88-93.

25. US Food and Drug Administration. Understanding the Vaccine Adverse Event Reporting System (VAERS). US Food and Drug Administration Web site. Available at: http://www.fda.gov/downloads/BiologicsBloodVaccines/SafetyAvailability/VaccineSafety/UCM298183.pdf. Accessed October 15, 2014.

26. Centers for Disease Control and Prevention (CDC). Suspension of rotavirus vaccine after reports of intussusception--United States, 1999. MMWR Morb Mortal Wkly Rep. 2004;53:786-789.

27. Greene SK, Kulldorff M, Lewis EM, et al. Near real-time surveillance for influenza vaccine safety: proof-of-concept in the Vaccine Safety Datalink Project. Am J Epidemiol. 2010;171:177-188.

28. Iskander J, Broder K. Monitoring the safety of annual and pandemic influenza vaccines: lessons from the US experience. Expert Rev Vaccines. 2008;7:75-82.

29. Klein NP, Fireman B, Yih WK, et al. Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures. Pediatrics. 2010;126:e1-e8.

30. DeStefano F, Price CS, Weintraub ES. Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism. J Pediatr. 2013;163:561-567.

31. Centers for Disease Control and Prevention (CDC). Epidemiology and prevention of vaccine-preventable diseases. The Pink Book, Course Textbook, 12th ed. Available at: http://www.cdc.gov/vaccines/pubs/pinkbook/safety.html. Accessed November 17, 2014.

32. World Health Organization (WHO). Measles outbreak in Europe. Global alert and response. Available at: http://www.who.int/csr/don/2011_04_21/en/index.html. Accessed March 8, 2012.

Hib: Contained but not eradicated

Hib was once the leading cause of meningitis and a major cause of other invasive bacterial diseases, but it has been greatly controlled since the advent of routine Hib vaccination in 1990.¹¹Hib is an encapsulated, gram-negative coccobacillus. There are 6 major capsular serotypes of Haemophilus influenzae, but serotype b was linked to major invasive disease in humans 95% of the time.¹²The spectrum of diseases caused by Hib is seen in TABLE 2.^13-15Hib is transmitted by respiratory droplets from noninfected as well as infected carriers. Asymptomatic nasal carriage in the pre-vaccine era varied from 0.5% to 5%.¹²

Hib is primarily a disease of young children, with almost all cases occurring in children younger than 5 years of age (66% in those younger than 18 months). Other risk factors for invasive disease are those that increase the spread of respiratory droplets: crowding, lower socioeconomic status, day care attendance, large household size, and school-aged siblings. American Indian and Alaskan Native populations remain at higher risk due to incomplete vaccination rates and the sociodemographic risk factors noted above. Breastfeeding is protective.¹²

Three percent to 6% of cases of invasive Hib disease are fatal; another 20% can have long-term sequelae such as hearing loss. In the early 1990s, the peak incidence of Hib disease reached 41 cases per 100,000 population.¹²The reduction in incidence of Hib disease brought about by universal vaccination has been attributed to individual immunity, decreased asymptomatic nasal carriage, and herd immunity.¹²

Despite this progress, Hib continues to evade eradication. In Minnesota in 2008, 5 children, ages 5 months to 3 years, contracted invasive Hib disease (3 with meningitis, 1 with pneumonia, 1 with epiglottitis).¹⁶Of the 5, only one was up to date with Hib vaccination; the others had not received vaccine because of shortages or parent refusal. These children were unrelated and had not been in contact with each other.

In a daycare outbreak in the United Kingdom, 2 cases of Hib disease (meningitis and septic arthritis) were identified in fully immunized children younger than 18 months, presumably due to a lack of complete vaccine efficacy.¹⁷A study of nasal carriage (performed just prior to rifampin prophylaxis) among other attendees and caregivers revealed 3 asymptomatic carriers.¹⁷Although Hib is largely well-contained in developed countries due to vaccination policies, the burden of disease in developing countries is estimated to be approximately 8.1 million serious illnesses with 371,000 deaths annually.¹³

The totality of morbidity and mortality prevented by vaccines

It is estimated that using just 9 routinely recommended vaccines prevents  42,000 deaths and 20 million cases of disease in every birth cohort. Measles and Hib are 2 examples of vaccine-preventable diseases and the reduction in morbidity and mortality achievable with vaccines. TABLE 3¹⁸summarizes the number of pre-vaccine era cases for selected diseases. Routine vaccination against 7 common childhood diseases not only prevents many thousands of deaths, as mentioned earlier,¹but it saves $13.5 billion in direct costs in each birth cohort and saves society $68.8 billion in costs that include disability and lost productivity of both patients and caregivers.¹

Put simply, every dollar spent on the vaccination program saves $10 in direct and indirect costs to society.¹Sustaining these successes and averting the resurgence of contained diseases requires a commitment to high immunization rates without delays and lapses—an effort made more challenging in light of misinformation about vaccine safety and resultant parental vaccine hesitancy.

Vaccine safety is ensured  by rigorous systems

 Despite an impressive record of safety, vaccines still cause anxiety among patients and parents in family practices. A recent survey identified concerns of long-term complications, autism, and thimerosal effects to be foremost on the minds of parents, whereas short-term effects were of much less concern.¹⁹Causation of autism related to vaccines has been dismissed; the initial linkages have been shown to be fraudulent.²⁰With the exception of some influenza vaccine preparations, thimerosal is no longer present in routinely administered children’s vaccines and has been shown not to be associated with autism.^21,22To address parents’ and patients’ concerns about vaccine safety, and especially those surrounding short- and long-term complications, physicians should have a general understanding of the pre- and post-licensure mechanisms in the United States.

Pre-licensure safety is under the purview of vaccine manufacturers and the Center for Biologics Evaluation and Research at the US Food and Drug Administration (http://www.fda.gov/biologicsbloodvaccines/vaccines/default.htm). For licensure, manufacturers must provide clinical data to demonstrate sufficient safety and efficacy. Accordingly, pre-licensure assessments are conducted in a “closed system” under a research protocol. The vaccine recipients are volitional research subjects selected according to inclusion and exclusion criteria. They are also compensated. However, sample sizes are rarely large enough to exclude rare serious adverse events.