Immunization is one of modern medicine’s greatest success stories. Yet we still lack vaccines for common diseases such as HIV and respiratory syncytial virus. Other vaccines are only moderately effective, like those against tuberculosis or pertussis. The average vaccine can take a decade or more to develop, at a cost of hundreds of millions of dollars, and vaccines that worked flawlessly in mice regularly fail in clinical trials. As a result, many companies are reluctant to enter into vaccine development.

“We need a way to rapidly assess vaccine candidates earlier in the process,” says Ofer Levy, MD, PhD, a physician-scientist in the Division of Infectious Diseases at Boston Children’s Hospital and director of the Precision Vaccines Program. “It’s simply not possible to conduct large-scale, phase 3, double-blind, placebo-controlled studies of every potential vaccine for every pathogen we want to protect against.”

In a paper published today in Frontiers in Immunology, Levy’s team describes the first modeling laboratory system for testing human immune responses to vaccines — outside the body. …