TRIALS OF ORAL BOVINE AND RHESUS ROTAVIRUS VACCINES IN FINLAND - A HISTORICAL ACCOUNT AND PRESENT STATUS

Live oral rotavirus vaccine strain RIT 4237, derived from group A bovi ne rotavirus NCDV, was given to human volunteers in Tampere, Finland i n 1982. Efficacy studies of this vaccine in 6-12 month-old children ga ve results characteristic of the performance of oral rotavirus vaccine s in general: 58% protective efficacy against any rotavirus gastroente ritis and 82% against ''clinically significant'' gastroenteritis. Four trials of RIT 4237 bovine rotavirus vaccine, one trial of group A RRV -1 rhesus rotavirus vaccine, and one trial of rhesus-human reassortant rotavirus vaccines D x RRV and DS1 x RRV were carried out between 198 3-1989. A meta-analysis of the protective efficacy of these vaccines i ndicated a 67% (95% C.I. 55-77%) efficacy against moderately severe ro tavirus disease and an 81% (95% C.I. 60-91%) efficacy against severe r otavirus disease. There was no apparent difference between bovine and rhesus-based rotavirus vaccines in the protective efficacy against sev ere rotavirus gastroenteritis. Problems associated with the use of any oral rotavirus vaccine include acid lability of the vaccine virus, wh ich requires buffering, and a slight but significant interference of o ral poliovirus vaccine with the uptake of rotavirus vaccine. In the ne ar future, oral heterologous rotavirus vaccines may be available for p revention of severe rotavirus gastroenteritis.