LIVE POLIO IRUS VACCINES

534 Efficacy-Field Evidence
a still smaller actual population, composed ress. Cooperation of the authorities on the
mainly of farmers, fishermen, and sailors, mostly island, as well as of the whole population, was
concentrated in a small village in the center of extremely good.
the island (Fig. 2). Modern conveniences are
uncommon and most households have outdoor
privies.
The vaccine, developed by the Lederle Labo-
FIG. 2.
Aerial photograph of Sottunga Island, Aland Archipelago, Finland.
During the winter, transportation to other
islands is very restricted, but during the summer
there is a bustling traffic between all the
islands in the archipelago.
At the start of the trial the population was
told about the purpose of the study and on
different occasions was informed about its progratories
Virus and Rickettsial Research Section,
was placed at our disposal by Dr. Herald R.
Cox.* For the first part of the trial only Type 1
* We wish to express our thanks to Dr. Cox and
to the Lederle Laboratories for help in connection
with the accomplishment of the trials.