Controlled field trial on the effectiveness of one and two doses of acetone-inactivated and dried typhoid vaccine.

A controlled field trial was carried out with acetone-dried vaccine on about 35 000 people on the Tongan islands of tongatapu and 'Eua where typhoid fever is endemic. Volunteers were distributed at random into 3 groups, 1 of which received 1 dose of typhoid vaccine and a second 2 doses; the third, a control group, received tetanus toxoid. The population was… CONTINUE READING