Influenza Vaccination of Health-care Personnel:

Disease, Vaccine, Beliefs, Barriers, and Recommended Strategies to Improve Vaccination

Adapted from presentations by Gina T. Mootrey, DO, MPH and William Atkinson, MD, MPH,
Centers for Disease Control and Prevention

HHS Initiative for Influenza Vaccination of Health Care Personnel: Components

• Two components
  • Improving HHS health care employee influenza vaccination, with focus on
    • Federal Occupational Health
    • Indian Health Service
    • U.S. Public Health Service Commissioned Officers
    • NIH Clinical Center
    • CDC
  
  
• Promoting influenza vaccination to non-federal health care organizations and HCP

HHS Initiative for Influenza Vaccination of Health Care Personnel: HHS Employees

Three focus areas

• Developing office and agency specific strategies to improve HCP vaccination levels

• Measuring employee vaccination rates

• Disseminating a toolkit containing
  • Standard presentation
  • Relevant articles
  • Posters
  • Fact sheets, questions and answers
  • Vaccine information statements
  • Links to other resources
  • Toolkit will be available on HHS OPHS website

HHS Initiative for Influenza Vaccination of Health Care Personnel: Outreach

Influenza

• Highly infectious viral illness
• 3 pandemics in 20th century
• Estimated 21 million deaths worldwide in pandemic of 1918-1919
• Virus first isolated in 1933

Influenza Pathogenesis

• Respiratory transmission of virus likely major route of transmission
• Replication in respiratory epithelium with subsequent destruction of cells
• Viremia rarely documented
• Viral shedding in respiratory secretions for 1 day before illness and 5-10 days after illness onset

Impact of Influenza-United States

• 5% to 20% of the population are infected every year.

• Approximately 36,000 annual influenza-associated deaths on average

• Persons 65 years of age and older account for more than 90% of deaths

• Higher mortality during seasons when influenza type A (H3N2) viruses predominate

Impact of Influenza-United States

• Highest rates of complications and hospitalization occur among young children and person 65 years and older

• Average of more than 200,000 influenza-related excess hospitalizations annually

• 57% of hospitalizations among persons younger than 65 years of age

• Greater number of hospitalizations during type A (H3N2) epidemics

Impact of Influenza in HCP

• In one randomized controlled trial of influenza vaccination of HCP, between 7.1% and 26% of unvaccinated HCP had documented serologic evidence of influenza infection in any one year.

• Of these, 42% could not recall having a febrile respiratory illness¹

¹ Wilde et al., JAMA 1999;281:908—13

Impact of Influenza Vaccination of HCP on patients

• Over 12 years in one hospital, vaccination coverage increased from 4% to 67%
  • Laboratory-confirmed influenza cases among HCP decreased from 42% to 9%
  • Nosocomial cases among hospitalized patients decreased 32% to 0 (p<0.0001)¹
  
  
• Two randomized controlled trials evaluated impact of HCP influenza vaccination on residents in nursing homes^2,3
  • They estimated > 40% decrease in overall mortality among residents in the setting of high employee vaccination levels, regardless of patient vaccination levels.

¹ Salgado et al., Inf Cont Hosp Epi 2004;25:923-8
² Carman et al., Lancet 2000;355(9198): 93--7
³ Potter, et al., J Infect Dis 1997;175:1--6

Influenza Vaccines

• Inactivated subunit (TIV)
  • intramuscular
  • trivalent
  • split virus and subunit types
  • Yearly vaccination
  
  
• Live attenuated vaccine (LAIV)
  • intranasal
  • Trivalent
  • Yearly vaccination

Inactivated Influenza Vaccine Effectiveness in Adults < 65 years

• 80% (95% CI 56% to 91%) efficacious when vaccine matched circulating strain

• 50% (95% CI 27% to 65%) when not well matched
  • Jefferson, et al. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD001269.

LAIV Effectiveness in Healthy Adults

• Randomized, double-blind, placebo-controlled challenge study
  • 92 healthy adults (LAIV, n = 29; placebo, n = 31; inactivated influenza vaccine, n = 32) aged 18--41 years ne (Treanor et al., Vaccine 1999;18:899--906.)
  • Overall efficacy of LAIV and inactivated influenza vaccine in preventing laboratory-documented influenza 85% LAIV and 71% TIV
  
  
• Nichol et al., JAMA 1999;282:137—44, study in 1997-98 with suboptimal vaccine-wild virus match; no virologic-proven outcomes
  • 24% fewer febrile upper respiratory illness episodes (URI)
  • 27% fewer lost work days due to febrile URI
  • 41%-45% fewer days of antibiotic use

Inactivated Influenza Vaccine Adverse Reactions

Live Attenuated Influenza Vaccine
Adverse Reactions in Adults

18-49 years adults in one clinical trial, signs and symptoms reported more frequently among LAIV recipients (n = 2,548) than placebo recipients (n = 1,290) within 7 days after each dose included

• cough (14% and 11%, respectively)
• runny nose (45% and 27%, respectively)
• sore throat (28% and 17%, respectively)
• chills (9% and 6%, respectively)
• tiredness/weakness (26% and 22%, respectively)

Belshe RB et al. Clin Infect Dis 2004;39:920--7.

Influenza Vaccination of Health-care Personnel

• Only 42 percent of U.S. health-care personnel were vaccinated in 2006

MMWR 2006;55 (RR-2). February 24, 2006.

Reasons for Accepting Vaccination Among Health-care Personnel

Christini AB, et al. Infect Control Hosp Epidemiol 2007;28:171-7

Reasons for Rejecting Vaccination Among Health-care Personnel

*Vaccine needs to be made available during all employment shifts.

Christini AB, et al. Infect Control Hosp Epidemiol 2007;28:171-7

Health Care Worker Groups

• Qualitative Assessment of Factors Influencing Immunization of Health Care Workers, CDC, unpublished data
  • Individual in-depth interview or focus group at hospitals in 4 cities (NYC, Hollywood (FL), Scottsdale (AZ), San Francisco, August 2007
  
  
• Results
  • Professional schools were reported as a driver of vaccination
  • Believe vaccines are a mechanism to protect themselves from patients, rather than as a means to protect patients
  • Clinical workers demonstrated limited or inaccurate knowledge of infectious diseases and their routes of transmission
  • Resistance to seasonal influenza vaccination was characterized by:
    • Perceptions of limited applicability to themselves
    • Perceptions of minimal consequences from contracting flu
    • Pronounced lack of trust in the vaccine

Literature review
Hofman F, Ferracin C, Marsh G, Dumas R. Infection 2005; 34:142-147

• Literature review of 32 studies performed 1985-2002
  • US, Canada, Europe
  
  

• Vaccination rates 2.1% - 82%

• Ideas encouraging influenza vaccination
  • To protect oneself (33-93%) - strongest motivation
  • To protect patients (2-98%) -secondary motivation
  • Free and convenient (11-58%)
  • Being previously vaccinated
  • Following the example set by peers
  
  

Literature review
Hofman F, Ferracin C, Marsh G, Dumas R. Infection 2005; 34:142-147

• Ideas preventing influenza vaccination
  • Fear of adverse events (8-54%)
  • Misconception that vaccination can cause influenza (10-45%)
  • Not at risk (6-58%)
  • Times/locations of vaccination were unsuitable (6-59%)
  • Doubt that influenza is a serious disease (2-32%)
  • Lack of vaccine efficacy (3-32%) - except physicians
  • Fear of injections (4-26%)
  
  
• 2 main barriers:
  • Misperception of influenza, its risks, the role of HCW in its transmission to patients, and the importance and risks of vaccination
  • Lack of (or perceived lack of ) conveniently available vaccine

Common Themes

Notable Differences

• Differences in motivators, barriers and beliefs by
  • Category of healthcare worker
  • Type of institution
  • Age
  • Level of knowledge about influenza and vaccine
  • Level of trust

Strategies for Improving HCP Vaccination Rates

• Successful HCP vaccination programs are multifaceted and combine:
  • Education campaigns
  • Role models
  • Improved access
  • Measurement and feedback
  • Legislation and regulation
  
  
• Task Force on Community Preventive Services currently conducting a systematic review of influenza worksite vaccination

Month of Peak Influenza Activity United States, 1976-2006

MMWR 2007;55(RR-6):5

Support from Professional Groups

• American College of Physicians (ACP)³
  • October 2007 - Recommendation that annual influenza vaccine should be required for every health care worker with direct patient care activities.
• Infectious Diseases Society of America  (IDSA)²
  • January 2007- Recommendation that U.S. adopt policy to include mandatory annual influenza vaccination among healthcare workers
• Joint Commission on Accreditation of Healthcare Organizations (JCAHO)¹
  • New standard, effective 1/1/07: Influenza immunization offered to staff and licensed independent practitioners.
• National Foundation for Infectious Diseases (NFID)⁴
  • Call to Action recommendations and Best Practices for immunizing health care personnel against influenza

¹ http://www.jcrinc.com/26813/newsletters/12882/, accessed 11/11/07;
² Pandemic and Seasonal Influenza Principles for U.S. Action, January 2007;
³ http://www.acponline.org/college/pressroom/hcw.htm, accessed 11/13/07;
⁴ http://www.nfid.org, accessed 05/15/08.