Immunogenicity of a locally produced hepatitis B vaccine with the birth dose stored outside the cold chain in rural Vietnam.
The heat stability of hepatitis B vaccine (HepB vaccine) should enable its storage outside the cold chain (OCC), increasing access to the birth dose in areas lacking refrigeration. We compared the immunogenicity of a locally produced vaccine among infants who received three doses stored within the cold chain (n = 358) or for whom the first dose was stored OCC for up to one month (n = 748). Serum was collected from these infants at age 9-18 months. The vaccine was protective in 80.3% of all infants. There were no differences in the prevalence of a protective level of antibody or antibody titer among groups of infants according to storage strategy. Differences in antibody titer between certain groups of infants could be explained by different vaccination schedules. Where birth dose coverage will be improved, HepB vaccine can be taken OCC for up to one month without affecting its immunogenicity.
International Health Unit, Burnet Institute, Alfred Medical Research and Education Precinct, Prahran, Victoria, Australia.
David B
DB
Hipgrave
Trung Nam
TN
Tran
Vu Minh
VM
Huong
Do Tuan
DT
Dat
Nguyen Tuyet
NT
Nga
Hoang Thuy
HT
Long
Nguyen Thu
NT
Van
James E
JE
Maynard
Beverley-Ann
BA
Biggs
D003080:Cold Temperature; D004356:Drug Storage; D005260:Female; D006509:Hepatitis B / Q000097:blood / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D012034:Refrigeration; D012424:Rural Population; D016896:Treatment Outcome; D014744:Vietnam
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines