Half-life of human parainfluenza virus type 3 (hPIV3) maternal antibody and cumulative proportion of hPIV3 infection in young infants.
During a phase 2 trial of parainfluenza virus type 3 (PIV3) vaccine, sequential serum samples were obtained from infants at 2, 6, 7, 12-15, and 13-16 months of age. Paired serum samples obtained at 2 and 6 months of age were used to estimate the biologic half-life of human PIV3 (hPIV3) maternal antibody in young infants. On the basis of the assumption that hPIV3 maternal antibody decays exponentially and constantly, the biologic half-life was estimated without adjusting for body weight increases. Cumulative proportions of hPIV3 infection in young infants were further estimated after adjusting for maternal antibody decline. A hemagglutination inhibition assay was used to quantify hPIV3 antibody. The mean (95% confidence interval) biologic half-life was estimated to be 51 (42-60) days, on the basis of which cumulative proportions of hPIV3 infection were estimated to be 11% at 6 months of age, 47% at 12-15 months of age, and 50% at 13-16 months of age.
Lee
M S
MS
Aviron, 297 N. Bernardo Ave., Mountain View, CA 94043, USA. mslee007@us.sina.com
Mendelman
P M
PM
Sangli
C
C
Cho
I
I
Mathie
S L
SL
August
M J
MJ
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002417:Cattle; D002641:Chicago; D005260:Female; D005500:Follow-Up Studies; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007223:Infant; D015141:Los Angeles; D022241:Parainfluenza Vaccines / Q000009:adverse effects / Q000627:therapeutic use*; D010224:Parainfluenza Virus 3, Human / Q000276:immunology*; D018184:Paramyxoviridae Infections / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D015143:Philadelphia; D011247:Pregnancy; D018108:Respirovirus / Q000276:immunology; D014505:Urban Population; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000627:therapeutic use*
D000914:Antibodies, Viral; D022241:Parainfluenza Vaccines; D014613:Vaccines, Attenuated