# Presentation: 643030

## Polio Eradication -- Global Progress and Development of Post-Eradication Strategies: Implications for U.S. Stockpile and Outbreak Response Preparations

- National Vaccine Advisory Committee
- February 8-9, 2005

## Objectives of Session

- To provide update on polio eradication progress & plans for post-eradication era
- To provide update on U.S. success in eliminating all forms of paralytic polio & status of U.S. polio vaccine stockpile
- To elicit committee discussion re: key actions for U.S. stockpile

## (III)Elimination of Paralytic Poliomyelitis in U.S.A.

## Epidemiology of Polio – U.S.A. (I)

- Routine childhood immunization program
- IPV (1950s) & OPV (1960s)
- Elimination of indigenous wild polio (1979) & imported wild polio (1993)
- Adverse effects of oral polio vaccine
- VAPP: average 9 cases / year
- Accepted as necessary consequence of OPV use, to reduce risk of imported wild polio

## Paralytic Poliomyelitis and OPV licensing  United States, 1960-1969

** **

- YEAR

- No. of Cases

- tOPV

- VAPP Cases

- type 3 mOPV

- type 1 mOPV    type 2 OPV

**Notes:**
...This is the previous graph I showed with the number of VAPP cases superimposed on a secondary axis (with different scale). We see a drop in the number of wild-poliovirus infections after the licensing of type 1 and 2 mOPV, but a spike in VAPP cases the year that type 3 monovalent OPV was licensed. 
After 1963, when trivalent OPV replaced monovalent versions, we see a drop in he number of cases and then a leveling off by the late 60s [pointer].

## Paralytic Poliomyelitis, United States, 1980-1989

** **

- YEAR

- No. of Cases

**Notes:**
In this graph of polio in the 1980s, the change in the epidemiology of polio is obvious:  Most cases of paralytic polio this decade were associated with OPV use.  

## Epidemiology of Polio – U.S.A. (II)

- Cessation of OPV in U.S.
- Global polio eradication progress in 1990s:
- Lower risk of imported wild poliovirus in USA
- Changing benefit / risk ratio for OPV
- VAPP = unacceptable risk
- Transition to IPV:
- Sequential IPV-OPV schedule (1997)
- All IPV schedule (2000)
- Last VAPP cases occurred in 1999

##  Paralytic Polio Cases and OPV Doses DistributedUnited States, 1990-2003

**Year**

**VAPP cases**

**OPV doses in millions**

**IPV-OPV**

**All-IPV**

**Notes:**
This is the previous graph with the VAPP cases that occurred during the sequential schedule (1997-1999) highlighted. Recall that a 41-53% reduction was predicted. 1990-1996 there was a median of 7 cases per year compared to 4.3 1997-1999, an overall, reduction of 38%. Why didn’t we see a higher reduction? The schedule was not followed 100%.  If fact, none of the 13 cases that occurred 1997-1999 had followed the sequential schedule; no VAPP case was reported in a child who had received a first and/or second dose of IPV..   I consider this the most important finding of this study for its global implications. 

		9 recipients: 7 OPV1-2, 2 OPV3-4; 
		 2 contacts: 1 OPV1, 1 OPV4; 
		 2 IDEF: 2 OPV2

## Epidemiology of Polio – U.S.A. (III)

- Post-OPV Cessation Era
- High vaccination coverage maintained (2002 NIS)
- High seroimmunity to all 3 serotypes after IPV-OPV or all-OPV schedules (urban areas) (Prevots et al.)
- Paralytic Polio: Current & future risks
- Source: Imported wild virus (primary)
- Risk groups:
- Under-vaccinated children in urban areas
- Vaccine refusers in religious communities
- Magnitude: very low but not zero

## Epidemiology of Polio – U.S.A. (Conclusion) 

- The U.S. has reached an important milestone – elimination of VAPP, through OPV cessation & transition to IPV.
- A low risk of polio cases or outbreaks in the U.S. remains until the world is polio-free.
- A polio vaccine stockpile, as approved, will help ensure an effective control of future outbreaks.

## (IV)U.S. Polio Vaccine Stockpile & Outbreak Response: Status, Issues & Future Directions

## Outline

- Topics:
- IPV stockpile
- OPV stockpile
- Global collaboration
- State & local collaboration
- Sabin IPV
- Antiviral drug

- Order of presentation:
- NVAC/ACIP Report
- Current Status & Issues
- Future Directions
- Points for Discussion

## U.S. Polio Vaccine Stockpile: IPV (I)

- NVAC/ACIP report:
- Projected / recommended = 8 million doses
- Used alone / with OPV for outbreak control
- Need for licensed, uncombined IPV
- Current status & issues:
- Current = ~4 million doses & holding
- Might be difficult to get 8 million doses of uncombined IPV under current mechanism

## U.S. Polio Vaccine Stockpile: IPV (II)

- Future directions
- Continue efforts to develop uncombined IPV stockpile through Pediatric Vaccine Stockpile
- Consider other options for IPV stockpile
- Discussion points
- How to maintain target supply of uncombined IPV long-term?
- IPV stockpile: U.S. issue only or global one?

## U.S. Polio Vaccine Stockpile: OPV (I)

- NVAC/ACIP report:
- Access to & effective use of OPV in outbreak
- Needed = 8 million doses (tOPV or each mOPV serotype)
- Preferred type = mOPV, if available
- Need to develop mechanism for use (IND vs other)
- Current status & issues:
- IND for OPV
- Need to identify vaccine manufacturer and specific OPV product to continue

## U.S. Polio Vaccine Stockpile: OPV (II)

- Future directions
- Discuss regulatory options with FDA
- Work with WHO & vaccine manufacturers re: mOPV
- Develop IND & explore other emergency response use mechanisms
- Discussion points
- Proceed to mOPV stockpile without tOPV?
- Are there other emergency response mechanisms to use?

## U.S. Polio Vaccine Stockpile: Global Collaboration (I)

- NVAC/ACIP report:
- CDC, FDA, WHO & other int’l partners
- Finance, create & maintain global PVS
- Guaranteed & immediate U.S. access
- Current status & issues:
- CDC & WHO staff – ongoing collaboration on stockpile & outbreak response
- CDC will collaborate with FDA & other agencies – regulatory issues & mechanisms for use of vaccines

## U.S. Polio Vaccine Stockpile: Global Collaboration (II)

- Future directions
- Support WHO efforts to...
- License mOPV & develop mOPV stockpile
- Evaluate the safety of Sabin IPV (sIPV)
- Assess potential use of antiviral drug
- Determine appropriate global stockpile size, composition & regulation
- Discussion points (sIPV & antiviral drug)

## U.S. Polio Vaccine Stockpile: State & Local Collaboration

- NVAC/ACIP report:
- Develop polio outbreak response plans
- Current status & issues:
- Outbreak response plan being drafted
- Future directions / discussion
- Involve CSTE, NACCHO & others in outbreak response plan development

## U.S. Polio Vaccine Stockpile: Sabin IPV

- Global developments
- Well outlined in Dr. Cochi’s presentation
- Discussion points
- Efficacy? Safety? Source?
- Issues for potential licensure of sIPV in US for stockpile use?
- Emergency use only (IND and/or other)?

## U.S. Polio Vaccine Stockpile: Antiviral Drug

- Developments & issues
- Outlined in Dr. Cochi’s talk
- WHO-CDC-Private collaborative group
- Exploring potential candidate antiviral drugs
- Wider consideration: proposed NAS meeting
- Discussion points
- Support for NAS-sponsored meeting?
- Potential to add as component of stockpile?

## U.S. Polio Vaccine Stockpile: Conclusions

- U.S. stockpile: not yet a reality -- optimal size, composition & use
- IPV stockpile: affected by economic issues
- OPV stockpile: direction pending
- Global developments re: mOPV
- Regulatory issues / emergency use options
- Potential products: evaluation / development
- Sabin IPV, Antiviral Drug

## Acknowledgements

- WHO
- David Heymann
- Bruce Aylward
- Roland Sutter
- Anna-Lea Jenny
- Harvard SPH & other
- Kim Thompson
- Rad Tebbens
- Marc Collett

- CDC
- Hamid Jafari
- Denise Johnson
- Linda Venczel
- Margie Watkins
- Nalinee Sangrujee
- Mark Pallansch
- Jane Seward
- Lorraine Alexander
- Kristin Kenyan

## Thanks!

## U.S. Polio Vaccine Stockpile: Discussion (I)

- IPV Stockpile:
- How to maintain target supply of uncombined long-term?
- IPV stockpile: U.S. issue only or global one?
- OPV stockpile:
- Proceed to mOPV stockpile without tOPV?

## U.S. Polio Vaccine Stockpile: Discussion (II)

- Sabin IPV:
- Efficacy? Safety? Source?
- Issues for potential licensure of sIPV in US for stockpile use?
- Emergency use only (IND or other)?
- Antiviral drug:
- Support for NAS-sponsored meeting?
- Potential to add as component of stockpile?

## Extra slides

## Paralytic Poliomyelitis United States, 1951-1959

** ****IPV licensed **

- YEAR

- Poliomyelitis Cases

- *

## Paralytic Poliomyelitis United States, 1970-1979

** **

- YEAR

- No. of Cases

**Notes:**
This slide shows polio cases in the 1970s.  In this decade we continue to have outbreaks of naturally occurring polio, but 1972 was the last year where naturally occurring (or non-vaccine-associated cases) exceeds the number VAPP cases . 
The median number non-VAPP cases was 4 this decade, whereas the median number of VAPP cases was 8.5 . This trend of more VAPP than non-VAPP cases led to  Institute of Medicine involvement in 1977.