Tdap Booster and 2-Dose Varicella Vaccine Requirement Implementation and Impact on Disease

Incidence: Implications for Maine

Paul Livingston, MPHPublic Health Prevention Service Fellow

Office for State, Tribal, Local and Territorial SupportCenters for Disease Control and Prevention

2015 PHAP Summer SeminarJune 3, 2015

Centers for Disease Control and Prevention

Office for State, Tribal, Local and Territorial Support

Introduction/Background Recent recommendations from ACIP on

pertussis and varicella vaccination* Tdap booster from 11-18 years 2nd dose of varicella vaccine from 4-6

years Not yet mandated in all states for school

attendance 44 states have a Tdap booster mandate 38 states have a 2-dose varicella

requirement Key questions:

What has happened to incidence rates in state that have mandated?

What can states that have not mandated learn from those that have?

* ACIP 2006, 2007

Pertussis and Varicella Requirements-National Picture

Immunization Action Coalition-2015

• No 2-dose varicella mandate:• Montana• Illinois• Oklahoma• Alabama• South Carolina• New Jersey

• No Tdap booster mandate• Maine• South Dakota• Delaware• Hawaii• Montana

Pertussis and Varicella Requirements-Maine

1 dose of varicella vaccine for entering kindergarten and 1st grade

5 doses of DTP but NO booster dose

Allows exemptions: Medical Religious Philosophical

Maine Department of Health and Human Services- Immunization Requirements for School Children: 10-144, Chapter 261: 05-071, Chapter 126. 2001.

Methodology Begun in January 2014

Stakeholders in Maine Federal PIRAT and Maine IRB approval

Data request to states that adopted and mandated pertussis and/or varicella requirements 2006-2012 0-19 year olds case Implemented mandate prior to and

including 2009-2010 school year

Removed from sample if: Incomplete or not able to provide data Unresponsive to data request

45 38

Pertussis Varicella

4 (only varicella)

8 (only pertussis)

10 (both pertussis and

varicella)

Sample Size

Methodology Census data for 2010 and intercensal population estimates

for 0-19 year olds in states

SAS v. 9.3

Open Epi http://www.openepi.com/Menu/OE_Menu.htm

Survey Monkey Follow-up for all states that submitted data Qualitative questions on:

• Vaccination exemptions• Local epidemiology• Impression of effectiveness of immunization requirements

United States Census Bureau: http://www.census.gov

Findings-Pertussis Pertussis

17 states submitted reliable pre- and post- data relating to pertussis incidence to assess statistical significance

Maine had much higher comparative disease incidence to states in the sample

Average increase in cases prior to implementing Tdap booster: 18.9 cases

Average increase in cases after implementing Tdap booster: 40.5 cases

Average increase in disease incidence prior to implementing Tdap booster: 0.1 cases per 100,000

Average increase in disease incidence after implementing Tdap booster: 7.1 cases per 100,000

Pertussis Incidence Rates: 2006-2012

MAINE

Pertussis Cases

Two-sided confidence interval 95%

Sample size Mean Std. Dev. Std. ErrorGroup-1 (Pre-

Requirements) 17 18.9 248.8

Group-2 (Post-Requirements) 17 40.5 146.3

F statistics df (numerator, denominator) p-value1

Test for equality of variance2 2.89209 16,16 0.04080 1 p-value (two-tailed)2 Hartley's f test for equality of variance

Average Pertussis Case Change-2 years Pre-vaccination Requirements vs. 2 years Post-vaccination requirements

Two-sided confidence interval 95%

Sample size Mean Std. Dev. Std. ErrorGroup-1 (Pre-

Requirements) 17 0.1 13.7

Group-2 (Post-Requirements) 17 7.1 17.4

F statistics df (numerator, denominator) p-value1

Test for equality of variance2 1.61309 16,15 0.3609 1 p-value (two-tailed)2 Hartley's f test for equality of variance

Average Pertussis Incidence Rate Change: Pre-vaccination Requirements vs. 2 years Post-vaccination requirements

Findings-Varicella

Varicella 10 states had reliable pre- and post- data relating to varicella incidence

to assess statistical significance All experienced overall decreases, only Maine experienced an increase Average decrease in cases prior to implementing 2-dose vaccination

requirement: 301.5 cases Average decrease in cases after implementing 2-dose vaccination

requirement: 422.5 cases* Average decrease in disease incidence prior to implementing 2-dose

vaccination requirement : 21.4 cases per 100,000 Average decrease in disease incidence after implementing 2-dose

vaccination requirement: 36.6 cases per 100,000*

*T-test-Statistically significant decrease (p<=0.05)

Varicella Incidence Rates: 2006-2012

Varicella Cases

Two-sided confidence interval 95%

Sample size Mean Std. Dev. Std. ErrorGroup-1 (Pre-

Requirements) 10 -301.5 841.3

Group-2 (Post-Requirements) 10 -422.5 372.7

F statistics df(numerator, denominator) p-value1

Test for equality of variance2 5.09546 9,9 0.02355

1 p-value (two-tailed)2 Hartley's f test for equality of variance

Average Varicella Case Change-2 years Pre-vaccination Requirements vs. 2 years Post-vaccination requirements

Two-sided confidence interval 95%

Sample size Mean Std. Dev. Std. Error

Group-1 (Pre-Requirements) 10 -21.4 16.7

Group-2 (Post-Requirements) 10 -36.6 32.9

F statistics df(numerator,denominator) p-value1

Test for equality of variance2 3.88114 9,9 0.055911 p-value (two-tailed)

2 Hartley's f test for equality of variance

Average Varicella Incidence Rate Change (per 100,000) -2 years Pre-vaccination Requirements vs. 2 years Post-vaccination requirements

Survey Monkey

Attempt to understand qualitative factors Exemptions Outbreaks Effectiveness of

immunization requirements

Survey Monkey Findings

Have school immunization requirements contributed to decrease in pertussis in your state?

Have school immunization requirements contributed to decrease in varicella in your state?

Cost-Benefit Review of Vaccination

Extensive literature review Public health Economic modeling

Pertussis Per hospitalization cost: $9,500-19,800 Outpatient visit cost: $88-150

Varicella Per hospitalization cost: $3,600-19,500 Outpatient visit cost: $70-224 2-dose varicella vaccine found to have additional cost savings of $343

per case prevented, or $109,000 per QALY*

*Zhou 2008

Conclusions/Recommendations Varicella

States that implemented a 2-dose varicella vaccination saw a statistically significant decrease in both varicella cases and incidence rates over 2006-2012

Maine increased in cases compared to states that implemented a 2-dose varicella vaccination

Cost effective at $343 per case prevented Recommendation to implement 2-dose varicella vaccination and

reconsider philosophical exemption Pertussis

States that implemented a Tdap booster saw a statistically significant increase in cases and insignificant increase in incidence rates

Epidemic year of 2012, cyclical epidemiology of pertussis Recommendation to reconsider philosophical exemption but collect

better data over longer period of time to understand need for Tdap booster requirement in Maine

References Advisory Committee on Immunization Practices (ACIP). Preventing Tetatnus, Diptheria, and Pertussis Among Adolescents: use of

Tetanus Toxoid, Reduced Diptheria Toxoid and Acelllular Pertussis Vaccines. Morbidity and Mortality Weekly Report March 24, 2006; 55 (RR03);1-34.

Advisory Committee on Immunization Practices (ACIP). Prevention of Varicella: Recommendations of the Advisory Committee on Immunization Practices. Morbidity and Mortality Weekly Report June 22,2007; 56 (RR04); 1-40.

Dean AG, Sullivan KM, Soe MM. OpenEpi: Open Source Epidemiologic Statistics for Public Health, Version. www.OpenEpi.com, updated 9/22/2014, accessed 3/30/2015.

Federal CDC: 2012 Final Pertussis Surveillance Report- http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6233a6.htm?s_cid=mm6233a6_w accessed 4/7/2015.

Federal CDC: 2013 Final Pertussis Surveillance Report: http://www.cdc.gov/pertussis/downloads/pertussis-surveillance-report.pdf accessed 4/7/2015.

Immunization Action Coalition-Varicella: http://www.immunize.org/laws/varicel_sec.asp accessed 4/7/2015. Immunization Action Coalition-Pertussis: http://www.immunize.org/laws/tdap.asp accessed 4/7/2015. Kattan JA, Sosa LE, Bohnwagner HD, Hadler JL. Impact of 2-Dose Vaccination on Varicella Epidemiology: Connecticut-2005-2008.

Journal of Infectious Diseases 2011; 203: 509-512. Lopez AS, Guris D, Zimmerman L, Gladden L, Moore T, Haselow DT, Loparev VN, Schmid DS, Jumaan AO, Snow SL. One Dose of

Varicella Vaccine Does Not Prevent School Outbreaks: Is it Time for a Second Dose? Pediatrics 2006; 117; e1070. Lopez AS, Cardemil C, Pabst LJ, Cullen KA, Leung J, Bialek SR. Two-Dose Varicella Vaccination Coverage Among Children Aged 7 years-

Six Sentinel Sites, United States, 2006-2012. Morbidity and Mortality Report v.63(8): February 28, 2014. Maine Department of Health and Human Services- Immunization Requirements for School Children: 10-144, Chapter 261: 05-071,

Chapter 126. 2001. Omer SB, Richards JL, Ward M, Bednarczyk RA. Vaccination Policies and Rates of Exemption from Immunization, 2005-2011. New

England Journal of Medicine v.367 (12): September 20, 2012. Parker AA, Reynolds MA, Leung J, Anderson M, Rey A, Ortega-Sanchez IR, Schmid DS, Guris D, Gensheimer KF. Challenges to

Implementing Second-Dose Varicella Vaccination during an Outbreak in the Absence of a Routine 2-Dose Vaccination Requirement-Maine, 2006. Journal of Infectious Diseases 2008; 197:S101-107.

United States Census Bureau: http://www.census.gov accessed 4/7/2015. Zhou F, Ortega-Sanchez IR, Guris D, Shefer A, Lieu T, Seward JF. An Economic Analysis of the Universal Varicella Vaccination Program

in the United States. Journal of Infectious Diseases 2008; 197:S156-64. Zhou F, Shefer A, Wenger J, Messonnier M, Wang LY, Lopez A, Moore M, Murphy TV, Cortese M, Rodewald L. Economic Evaluation of

the Routine Childhood Immunization Program in the United States, 2009. Pediatrics v.133(4): April 2014.

For more information, please contact CDC’s Office for State, Tribal, Local and Territorial Support

4770 Buford Highway NE, Mailstop E-70, Atlanta, GA 30341Telephone: 1-800-CDC-INFO (232-4636)/TTY: 1-888-232-6348E-mail: OSTLTSfeedback@cdc.gov Web: http://www.cdc.gov/stltpublichealth

The findings and conclusions in this presentation are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Thank You

Any Questions?

Paul Livingston, MPHvwg3@cdc.gov

Paul.livingston@maine.gov

Centers for Disease Control and Prevention

Office for State, Tribal, Local and Territorial Support