Threats and Challenges to
Childhood Health: Vaccines
Daniel Salmon, PhD, MPH
College of Medicine, University of Florida
Institute for Vaccine Safety, Johns Hopkins
Comparison of Maximum and Current Reported
Morbidity, Vaccine-Preventable Diseases and
Vaccine Adverse Events, United States
Disease Pre-vaccine Era* 2005 % change
Smallpox 48,164 0 100%
Diphtheria 175,885 0 100%
Measles 503,282 66 >99%
Mumps 152,209 314 >99%
Pertussis 147,271 25,616 83%
Polio (paralytic) 16,316 1 >99%
Rubella 47,745 11 >99%
Cong. Rubella Synd. 823 1 >99%
Tetanus 1,314 27 98%
H.Influenzae type b and 20,000 226 99%
Unknown ( 99%
Mumps 152,209 314 >99%
Pertussis 147,271 25,616 83%
Polio (paralytic) 16,316 1 >99%
Rubella 47,745 11 >99%
Cong. Rubella Synd. 823 1 >99%
Tetanus 1,314 27 98%
H.Influenzae type b and 20,000 226 99%
Unknown ( $75,000
• Parent expressed concern about vaccine
safety
Smith et al, Pediatrics, 2004.
School Immunization
Requirements in US
• All State Laws (not Federal)
• Wide Variability in Implementation
– Antigens required
– Process for adding antigens or making changes
– Applicable Populations
– Who provides documentation
Exemptions to School Immunization Laws
TYPE OF EXEMPTION(S) ALLOWED
Philosophic, Religious &
Medical (20)
Religious & Medical (29)
Medical only (2) updated March 2005
www.vaccinesafety.edu
State Implementation of Exemptions
• Wide variability
• Easy process = High rates
Rota et al. AJPH, 2000
Easy Exemption Process
Associated with High Rates
Exemption Rate
Administrative Low Medium High
Difficulty (1.0%)
RI, OK, MO, HI, WA, ID, WI,
Easy PA
AK, AZ, VT, CA, MD
MI, OR
ND, CT, IL, NC,
Medium AL, NY, OH, KS, MA UT, SD, CO
NJ, LA
WY, NH, MT, VA,
IA, DE, CS, ME, NM, TX, NV,
Hard IN, AR, MN, KY,
FL, NE
GA, TN
Rota et al AJPH, 2000.
State Implementation of Exemptions
• Wide variability
• Easy process = High rates
• Little contact between parents and health personnel
• Majority of states (67%) never deny exemptions
• States rely on schools to implement exemptions
Rota et al. AJPH, 2000.
Relative Risk of Measles and Pertussis in
Exemptors from School Laws
Measles Pertussis
CO (1987-98)1 22 5.9
U.S. (1985-1992)2 35
1= Feikin et al. JAMA. 2000.
2 = Salmon et al, JAMA. 1999.
School Exemption Rates in Counties
With and Without Pertussis
Outbreaks: Colorado
Counties with outbreaks 4.7%
Counties without outbreaks 1.3%
p = .001
Feikin et al, JAMA. 2000..
Mean State Percent and Inter-Quartile
Ranges of Non-Medical Exemptions by
Exemption Type, 1991-2004
Religious Personal Belief/Philosophical
4.0% 4.0%
3.0% 3.0%
Exemption Rate
Exemption Rate
2.0% 2.0%
1.0%
1.0%
0.0%
0.0%
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Omer et al., JAMA, 2006
Mean State Percent and Inter-Quartile Ranges
of Non-Medical Exemptions by Exemption
Ease, 1991-2004
Difficult Medium Easy
5.0%
5.0% 5.0%
4.0%
4.0% 4.0%
Exemption Rate
Exemption Rate
Exemption Rate
3.0%
3.0% 3.0%
2.0%
2.0% 2.0%
1.0%
1.0% 1.0%
0.0% 0.0%
0.0%
1990 1991 1992 19931994 1995 1996 1997 1998 1999 20002001 2002 2003 2004
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 20002001 2002 2003 2004 1990 1991 1992 1993 1994 1995 1996 19971998 1999 2000 2001 2002 20032004
Omer et al., JAMA, 2006
Associations between State Exemption
Policies and Pertussis Incidence, 1986-2004
Unadjusted IRR Adjusted IRR
(95% CI) (95% CI)
Type of exemption
Only Religious Exemption Reference Reference
Personal Belief Exemption 2.06 (1.77-2.40) 1.48 (1.03-2.13)
Exemption ease
Difficult Reference Reference
Medium 1.27 (1.06-1.51) 1.35 (0.96-1.91)
Easy 1.90 (1.60-2.28) 1.53 (1.10-2.14)
Adjusting for allowing parental signature for school immunization forms, proportion inside urbanized area, income
(11 categories), and education (7 categories)
Omer et al, JAMA, 2006
Within State Variations in
Implementing Exemptions
• Survey 1,000 schools in 4 states (CO, MA,
MO and WA)
• School Implementation Procedures
• School personnel KABs
Salmon et al, Pediatrics, 2004
Association Between School Policies
and Likelihood of Child Having an Exemption
LESS LIKELY TO NO MORE LIKELY TO
RESPONDENTS' REPORT OF SCHOOL POLICY CLAIM EXCEMPTION EFFECT CLAIM EXCEMPTION
1.64
School permits philosophical exemptions 1.13
.50
Instructions for completing immunization
requirement mailed to parents pre-enrollment1 .53 State Does Not Authorize
Philosophical Exemptions
(MA & MO)
.68
Increased administrative difficulty2 to claim State Authorizes
.88 Philosophical Exemptions
an exemption (CO & WA)
.85
If school permits philosophical exemptions,
letter required from parent .78
.70
School has authority to deny exemption request 1.08
1.10
Exemption ever denied 1.63
.96
School has written policy to inform parents
.84
of the exemption option
1 – MO only for black bar - Question not asked in MA .25 .5 1 2 4
2 – Administrative difficulty construct ranges from 0-4, based Odds Ratio and 95% Confidence Interval
on (1) requirements for annual renewal; (2) letter from
parent for religious exemption; (3) signature from religious Adjusted for type of school, whether respondent
leader, school or physician; and (4) informing parents was trained as nurse and the state
requesting exemption of risks of not vaccinating
School Personnel KABs Associated with
Children Having Exemption
• Training of school personnel
• Perceived Susceptibility and Severity of Disease
• Perceived Safety and Efficacy of Vaccination
• Who Benefits from Vaccination (Individual and
Community)
• Vaccine Misconceptions
– Children get more immunizations than are good for
them
– Concerned immune system weakened by too many
vaccines
• Confidence in local and state health departments
• Use of alternative medicine Salmon et al, AJPH, 2004.
WA State Counties’ School Entry Exemption Rates
2005-2006
Whatcom
San Juan 7.5%
15.2%
Okanogan Pend
Skagit 8.2% Ferry Stevens Oreille
7.7%
Island 14.3% 12.2% 12%
11.1%
Clallam
6.1% Snohomish
6.3%
Chelan
Jefferson 2.3%
19.4% Douglas Spokane
Kitsap 1% Lincoln 6.8%
6.4% King 7.1%
5.1%
Grays Mason
5.8%
Harbor Grant
4.8%
Kittitas 3.7%
Pierce 2.8% Adams Whitman
Thurston 3.9% 1.2% 3.1%
7%
Pacific Lewis
9.7% 3% Franklin Garfield
Yakima 1.3%
Columbia
1%
Wahkiakum Cowlitz Benton 4% Asotin
3.2%
Walla Walla 1.9%
4.5% 2.6% Skamania 2.7%
8.5%
Clark Klickitat
3.9%
5.4% Statewide Total: 5.1%
5.0%
WA State Dept. of Health – School Status Reports 2005-2006
Why Do Parents Claim Exemptions?
• Survey of the parents of 800 Exemptions
and 1600 Vaccinated children
– 4 states (CO, MA, MO & WA)
– Recruited from over 100 public and private
elementary schools
– Matched by state, school, & grade
Salmon et al. Archives of Ped and Adolescent Med. 2005.
Reasons Parents State for Not Vaccinating
Reason for Not Vaccinating 1 Freq. %
1. Vaccine might cause harm 190 69
2. Vaccines might overload immune system 136 49
3. My child not at risk for the disease(s) 103 37
4. Disease(s) not dangerous 58 21
1 Not Mutually Exclusive
Reasons Parents State for Not Vaccinating
[CONTINUED]
Reason for Not Vaccinating 1 Freq. %
5. Vaccine might not work 36 13
6. Ethical or moral issues 2 25 9
7. Contrary to religious beliefs 25 9
1 Not Mutually Exclusive
2 Includes use of aborted cell lines, fetal tissue and blood, animal
testing, opposed to requirements, and restatement of above issues
Parents Who Report a
Moderate or Great Deal of Benefit When a
Child Is Fully Vaccinated
% Non-Med Exempt
100
% Vaccinated
75
Percent
50
p0 to 5 to 10 to 15
of Education, Arkansas Department of Health and the 0 5 10 20 30
Census 2002 TIGER Lines Files. Miles
Thompson et al, AJPM, 2007
Impact of Philosophical Exemption
in Arkansas
Exemptions 2001-02 2002-03 2003-04 2004-2005
Total 529 651 764 1145
% Increase from
Previous Year 23% 17% 50%
Absolute
Increase from 122 113 381
Previous Year
Absolute or % Increase?
Thompson et al, AJPM, 2007
Association of Immunization
Managers (AIM) Position
• Must be used sparingly, approached
cautiously, and considered only after an
appropriate vaccine implementation period
– Funding for vaccine
– Physician/provider and public support
– Stable and adequate vaccine supply
– Adequate data to assure vaccine safety
– Significant uptake in the recommended
population to reduce the compliance burden on
the school/child care system
Association of Immunization
Managers (AIM) Position – cont.
• Inappropriate application of mandates risks loss of
support for immunization programs
• Must be pursued through existing state processes.
Legislators, advocates, consumer groups,
manufacturers, and others interested in pursuing
school and child care immunization requirements
should first contact the state health agency
immunization program.
Association of Immunization
Managers (AIM) Position – cont.
• Measures to add or alter exemptions to laws
must be carefully coordinated with state
immunization policy and goals. Opening
existing laws for this purpose risks having
an effective mandate weakened, altered in
an undesirable way, or even revoked
entirely.
Human Papillomavirus (HPV)
• Most common STI
• 100+ genotypes
• Often asymptomatic and transient
• Can lead to cervical, vaginal, vulvar, anal
and penile cancer and genital warts
• Vaccine highly efficacious against 4 strains
causing 70% of cervical cancer and 90% of
warts
Compulsory HPV Vaccine
• Texas
– All 6th grade girls in 2008
– Passed by Governor Order
• No public comment
– Overturned by legislature
Compulsory HPV Vaccine in Other
States
• 24 States and DC have laws pending
• Virginia passed HPV vaccine mandated
– Exemption for HPV vaccine expanded
– Exemption not changed for other vaccines
– May cause slippery slope
Threats and Challenges to
Childhood Health: Vaccines
Daniel Salmon, PhD, MPH
College of Medicine, University of Florida
Institute for Vaccine Safety, Johns Hopkins