Dr. Peter Katona, associate clinical professor of infectious diseases at the David Geffen School of Medicine at UCLA, said the shortfall "is in no way surprising" considering the many steps in the vaccine-making process that are prone to delay and other problems. Among these, he said, are the fact that normal vaccine production can be interrupted by a problem in a single plant, that the egg-based system of vaccine production is inefficient and archaic, and that the production of the swine flu vaccine coincides with the production schedule of the regular seasonal flu vaccine.
"In other words, a lot of things can go wrong," he said, "and the government doesn't have a great track record for predictions."
Still, the impact of the shortfall on vaccination efforts remains to be seen. Dr. Amir Afkhami Assistant Professor and Associate Director of Residency Training at the George Washington University School of Public Health and Health Services said any vaccine shortage that does arise will underscore the need to get the vaccine to those who need it the most.
"The impact of limited vaccine stocks will be that providers will need to prioritize vaccine delivery to immunization priority groups which are considered more vulnerable to the virus," he said.
He said that these groups includes pregnant women; those who come in close, daily contact with children under six months old; public health workers; all children between the ages of six months and 4 years old; and children ages 5-18 who have chronic medical conditions.
As for everyone else, Schaffner said that the public would do well to ensure that they at least adhere to recommendations on the seasonal flu vaccine.
"The regular flu shot will be available by the end of the month or beginning of September in doctor's offices, clinics, pharmacies," he said. "Everybody should go ahead and get themselves vaccinated against that."