A Model for Prioritizing Distribution of H1N1 Vaccine to Providers as It Became Incrementally Available in Fall of 2009

Background: In early October, 2009, H1N1 vaccine first became available incrementally, in limited quantities for distribution to Los Angeles (LA) County immunization providers who had preregistered on-line.  The total doses ordered by 3,264 registered LA County providers was 2,344,249, but by October 31, only 629,224 doses had become available for distribution.  There was a need to develop and implement a process for equitably distributing vaccine to providers likely to vaccinate the highest percentage of ACIP H1N1 target group members.

Setting: Large county urban health jurisdiction.

Population: Private health care providers that ordered H1N1 vaccine.

Project Description: As vaccine became available, it was divided among 8 LA County Service Planning Areas (SPAs) on a population pro-rata basis.  Registered immunization providers in each SPA were divided into priority groups 1, 2, and 3 based on their likelihood of serving ACIP H1N1 target group members. Vaccine orders were modified to reflect a provider’s estimate of target group members served.  Available vaccine was used to complete 0.5 of Group 1 provider orders and 0.2 of group 2 provider orders, by the criteria “date of first order.” Group 3 providers did not receive vaccine until all group 1 and 2 providers had received vaccine.  Providers erroneously placed in group 3 due to self-misclassification during initial registration were moved to groups 1 or 2. 

Results/Lessons Learned: After 8 weeks of vaccine availability, the percentages of 1,618,520 total doses distributed to each provider group were: Group 1, 66.8%; Group 2, 27.3%; and Group 3, 5.9%.  The proportion of doses received, to SPA population, was approximately 15%. This model allowed for a standardized approach to the distribution of H1N1 vaccine when vaccine availability was limited.