The American Centre for Disease Control (CDC) has recommended after an urgent meeting with the Advisory Committee of Immunization Practices the 5 priority groups for the new H1N1 influenza vaccine.

This includes:
· Pregnant women,
· household contacts of children who are younger than 6 months of age,
· healthcare workers and emergency medical services personnel,
· children and young people between the ages of 6 months and 24 years of age, and
· nonelderly adults with underlying risk conditions or medical conditions that increase their risk for complications from influenza.

According to the CDC, the seasonal influenza vaccine remains very important. "Our assumption is that it is very likely [that seasonal influenza and H1N1 vaccines] can be given together," said Dr. Schuchat. "There will be more data coming out...but it is likely they can be given at the same visit," she said. According to Dr. Schuchat, 2 doses of the vaccine will probably be needed, with 15μg antigen/dose.

According to John Bartlett, MD, chief of the Johns Hopkins University School of Medicine, Division of Infectious Diseases, Baltimore, Maryland: “Of interest is the observation that persons over 64 years, a high priority for seasonal flu vaccine, are not included here.” "That decision is based on the curious observation that the people born before 1957 appear to be relatively well protected from infection or serious disease with this strain of H1N1 virus." According to Dr. Bartlett, it appears that a similar strain circulated before 1957, accounting for this protection; other comparable viruses also have circulated more recently.

The concern remains that the vaccine is difficult to grow and it is unclear how many doses will be available and by when.