1. Evaluation of the 2004 pneumococcal conjugate vaccine shortage utilizing data from the Michigan Childhood Immunization Registry Norma Allred, PhD, John Stevenson, MA, Richard Schieber, MD, MPH, Abigail Shefer, MD, Maureen Kolasa, RN, MPH, Diana Bartlett, MS, Kyle Enger, MPH

2. Background Pneumococcal conjugate vaccine (PCV7) licensed in the US by Wyeth Lederle (Prevnar ®) 7 serotypes of S. pneumoniae account for the majority of cases of bacteremia, meningitis and acute otitis media in children < 6 years Routine schedule  doses are given at 2, 4, 6 months  booster at 12-15 months of age

3. PCV7 Timeline Feb 2000 Pneumococcal conjugate vaccine licensed Recommended for use in infants and young children by ACIP First shortage announced Recommendation to withhold vaccine for children over 2 unless high risk; Defer booster doses for healthy children less than 2; Continue to vaccinate all children <12 months of age Recommendation to defer doses for healthy children based on provider’s estimate of vaccine supply and age child received first dose Oct 2000 Aug 2001 Dec 2001

4. PCV7 Timeline May 2003 1 st shortage resolved and catch-up schedule published Announcement of potential for limited supply Recommendation to withhold 4 th dose for healthy children Recommendation to withhold 3 rd dose Reinstatement of 3rd dose Second shortage resolved; 4 th dose reinstated Dec 2003 Feb 2004 Mar 2004 July 2004 Sept 2004

5. Research questions Was there a decline in coverage for PCV7 doses 3 and 4 associated with the dates of the CDC announcements to withhold doses? Do coverage trends vary between pediatricians and family practitioners?

6. Objective Evaluate usefulness of registry data to evaluate trends in PCV7 coverage during the vaccine shortage of 2004

7. Methods Michigan immunization registry data (MCIR) from entire state  88% children < 6 years old enrolled with 2 or more shots  All public providers and 74% private enrolled and submit data Sample – all children born between January 2000 to August 2004 with at least one shot record Combine all vaccination data to create one record per child

8. Methods Calculate proportion of children receiving DTaP3 with those receiving PCV3 at 7 months of age Calculate proportion of children receiving MMR1 with those receiving PCV4 at 16 months of age Compare vaccine administration dates from registry to dates of interim recommendations to evaluate trends

9. Results 674,439 children had at least one shot record and are included in analysis Vaccination data analyzed through November 2004 Practice specialty – 42% pediatric, 15% family practice

10. Coverage for cohort turning 7 months First and second shortages 1 st shortage begins 1 st shortage ends 2 nd shortage begins 2004-Sept 2 nd shortage ends 2000-Jul

11. Coverage for cohort turning 16 months First and second shortages 1 st shortage begins 1 st shortage ends 2 nd shortage begins 2 nd shortage ends

12. Coverage for cohort turning 7 months 1 st shortage ends 2 nd shortage begins 2 nd shortage ends 2004-May 2004-Sept

13. Coverage for cohort turning 16 months 1st shortage ends 2 nd shortage begins 2 nd shortage ends 2004-Sept 2004-May

14. Coverage for cohort turning 7 months by Practice Type - Pediatrician and Family Practice 2 nd shortage begins 1 st shortage ends 2 nd shortage ends 2004-Sept

15. Coverage for cohort turning 16 months by Practice Type – Pediatrician and Family Practice 2 nd shortage begins 2004-Sept 1 st shortage ends 2 nd shortage ends

16. PCV7 coverage for 3, 5, 7 and 16 month old children by year and month First shortage ends 2 nd shortage begins 2nd shortage ends 04-Sept

17. Discussion Overall coverage rates for PCV3 and 4 did decline when recommendations made Decline in coverage similar for pediatricians and family practitioners Can we determine if these declines due to provider adherence to guidelines or a lack of vaccine?

18. Discussion Other studies - First shortage Freed survey on variation in public/private supplies of PCV7 conducted in Oct and Nov 2001  405 practices in 12 states Only 23% altered vaccine administration practices for private supply and 27% for public supply based on vaccine supply More than half stated unaware of national shortage until their supplies ran out – too late to prioritize vaccination at that point

19. Discussion Other studies - First shortage Broder et al–survey (11/02-3/03) of pediatricians evaluating first shortage experience and adherence (n=1412)  Most were aware of recommendations  Vaccinated public and private children in similar manner  Partially adhered to schedule – those with more vaccine had less adherence  Half sometimes or always gave 4 th dose

20. Discussion Other studies - First shortage Stokley survey on impact of vaccine shortages from 9/2001 to 1/2002 370 providers responded to questions on following interim recommendations for PCV during first shortage  29% implemented recommendations and 49% did not; 21% ran out of vaccine  Providers in universal purchase states less likely to implement recommendations compared to non-universal states

21. Discussion Other studies – Second shortage Bhatt et al – 2004 PCV shortage Telephone survey during March/April of 399 pediatricians’ offices to evaluate awareness, supply, adherence, tracking 92%+ aware of shortage, 80%+ deferring doses for healthy children One third of providers deferred 1 st and 2 nd doses due to short supplies

22. Limitations Incomplete ascertainment of records – not all data in registry so misclassification of immunization status possible Do not know if 3 rd and 4 th doses of Prevnar were not given by providers due to shortage of vaccine or adherence to guidelines Do not know if providers who give more of 3 rd and 4 th doses have more high risk children

23. Summary Registry data an effective method for evaluating coverage trends during a vaccine shortage Difficult to assess provider compliance unless have data on vaccine supplies Data can also be used to determine if children who had doses withheld during shortage receive those doses at a later date