The system required to deliver a vaccine is called the “cold chain,” so named for the set of facilities that keep a vaccine cold as it is distributed from the manufacturer to the people who need it.

To successfully deliver a vaccine to a remote village, relying on infrastructure already in place, we need a cold delivery vehicle that can survive for six months or longer with no power.

At the time, doctors revealed only that the vaccine-which USES an "adenovirus," or the common cold virus, to deliver HIV genes into the body-had not worked.