1. Impact of Rotavirus Vaccination in Latin America
Manish Patel
Viral Gastroenteritis Team
Epidemiology Branch
Division of Viral Diseases
National Center for Immunizations and Respiratory Diseases
CDC
* The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention (CDC).

2. Rotavirus causes half a million childhood deaths annually under 5
1 dot = 1000 deaths
Parashar et al. EIDJ 2005

3. Rotavirus Causes of a Third of the Diarrhea Hospitalizations Among Children <5
Industrialized Countries
Developing Countries
Unknown
Unknown
Rotavirus
Rotavirus
Other
Bacterial
Bacterial
Other
A. Kapikian, Fields Virology 2003

4. Rotavirus Vaccines: RV5 & RV1
RV1 Rotarix (GSK)
RV5 RotaTeq (Merck & Co.) G1 G3 G2 G4
P[8]
Bovine rotavirus with single human rotavirus gene substitution
G1P[8]
Human rotavirus

5. RV1 RV5 Tested against severe rotavirus disease
Efficacy in industrialized countries: 85%-96%
Efficacy in developing countries: 50-77%
RV5

6. 2006: WHO recommends rotavirus vaccination in Latin America and Eastern Europe
2009: WHO expanded rotavirus immunization recommendation globally

7. Rotavirus Vaccination in the Americas
United States – Feb 2006 and Jun 2008
Mexico: May 2007
Venezuela: Apr 2006
ELS: Oct 2006
Panama: Mar 2006
Nicaragua: Oct 2006
Ecuador, Oct 2007
Brazil: Mar 2006
Bolivia, Aug 2008
Slide – L Oliveira, PAHO 7 7

8. Postlicensure Issues of Priority
Vaccine performance in routine use
Effectiveness in low income settings
Impact on diarrhea mortality
Not assessed in trials 8

9. El Salvador & Nicaragua

10. Comparison of Countries
El Salvador
Nicaragua
Birth cohort
150,000
GNI
~2,800 US$
Low-middle
~980 US$
Low income
Vaccine
RV1
RV5
Year introduced
October, 2006
October 2006
Age
2, 4 months
2, 4, 6 months
Concomitant vaccines
OPV, DTP, HiB, Hepatitis B

11. Case-control Vaccine Effectiveness Evaluation—ELS & NIC
Active surveillance for diarrhea
Cases: overnight hospitalization for lab-confirmed rotavirus diarrhea
323 (ELS) and 285 (NIC)
Controls: 3 per case, matched on date of birth (+/- 4 weeks)
Card-confirmed vaccination status

12. Vaccine Effectiveness (95% CI)
Vaccine Effectiveness against Rotavirus Diarrhea Requiring Admission Differed by Country
No. of doses
Vaccine Effectiveness (95% CI)
El Salvador*
(RV1)
Nicaragua**
(RV5)
Full series
76% (63, 84)
44% (15, 63)
*De palma et al BMJ, in press
**Patel et al JAMA,2009

13. Vaccine Effectiveness (95% CI) Vesikari* ≥ 15 (MOST severe)
Disease Severity: Effectiveness was Comparable against the MOST Severe Rotavirus Diarrhea
Severity Score
Vaccine Effectiveness (95% CI)
El Salvador (RV1)
Nicaragua
(RV5)
Vesikari* ≥ 15 (MOST severe)
83% (52, 94)
77% (39, 92)
*Vesikari score is a 20-point clinical severity scoring system

14. Vaccine Coverage: Rapid Uptake in Both Countries*
Proportion of children 6-12 months of age receiving 2 doses of rotavirus vaccination in El Salvador*
*per Ministry of Health vaccine administration data

15. Rotavirus Trends: Large Reduction in Lab Confirmed Rotavirus Admissions among children < 5, El Salvador
70-80% reduction in rotavirus hospitalizations children < 5 years

16. Will Vaccination Impact Diarrhea Mortality?
Not assessed in clinical trials
Difficult to evaluate

17. Mexico
Pre-vaccine, annual median of ~1800 diarrhea deaths are reported among children < 5 years
RV1 introduction in 2006 & 2007
By December 2007, 74% of children under 1 year of age received 1 dose
Compared diarrhea mortality before and after vaccination
Richardson, V et al. NEJM 2010: 362;

18. What happened to Total Diarrhea Deaths after Vaccination, 2008-2009?
Vaccine Introduction
(May 2007)
2008
2009

19. Summary
Rotavirus vaccination is making a substantial real-world impact against diarrhea hospitalizations and deaths in the Americas
Gradient of protection that correlates with socioeconomic status—reasons remain unclear
Impact data from the Americas provide promise and highlight challenges for Asia & Africa

20. Acknowledgements
CDC Viral Gastro Group RVP Team – PATH PanAmerican Health Organization/WHO Nicaragua Ministry of Health El Salvador, Ministry of Health IMIP, Recife Brazil
Mexico Ministry of Health GAVI