The government has developed Guidance on Allocating and Targeting Pandemic Influenza Vaccine (PDF - 1.83 MB) which provides strong guidance to states, territories, and tribes for the allocation of limited supplies of vaccine, and describes the scientific and ethical framework for how this guidance was developed.

A tiered allocation for vaccines in severe pandemics is recommended with the following objectives considered to be the most important:

• protect those who are essential to the pandemic response and provide care for persons who are ill;
• Protect those who maintain essential community services;
• Protect children;
• Protect workers who are at greater risk of infection as a result of their job, and
• Protect those who maintain homeland and national security.

Because there will likely be a limited supply of vaccine, research is underway to develop adjuvants. An adjuvant is a substance that is added to a vaccine to improve the immune system's production of antibodies, which is the desired response to vaccines. The successful addition of an adjuvant means that a given supply of vaccine can be used to treat more people.