Even before any vaccine is available, some people are trying to boost their chances of access, said Dr. Allison Kempe, an expert in vaccine dissemination who is a professor of pediatrics at the University of Colorado School of Medicine. "People have called me and said, 'How can I get the vaccine?'" she said. "I think that not everyone will be happy to wait, that's for sure. I don't think there will be rioting in the streets, but there may be pressure brought to bear."