... born after 1951.During the 1984 survey 82 chronic carriers were identified in Keneba and 108 in Manduar. They have been followedat 3 time points 5 (in 1989), 9 (in 1993 )and 19 (in 2003)years after ... 26:192-197.21. Whittle HC, Maine N, Pilkington J, Mendy M, Fortuin M, Bunn J, Alli-son L, Howard C, Hall A: Long-term efficacy of continuing hep-atitis B vaccination in infancy in two Gambian villages ... H.25. Whittle HC, Maine N, Pilkington J, Mendy M, Fortuin M, Bunn J, Alli-son L, Howard C, Hall A: Long-term efficacy of continuing hep-atitis B vaccination in infancy in two Gambian villages....