Sadeck Lilian S R, Ramos José L A
Departmento de Pediatria, FMUSP, Sao Paulo, SP.
J Pediatr (Rio J). 2004 Mar-Apr;80(2):113-8.
To investigate the immune response of preterm infants to hepatitis B vaccination.
Three doses of recombinant hepatitis B vaccine (5 micro g dose) were administered to 35 preterm and 21 full-term infants within 24 hours after birth and at one and six months of postnatal age.
A protective antibody response (anti-HB > 10 mUI/mL) was observed three months after the last dose in 92.6% and 100% of preterm and full-term infants (p > 0.05), respectively. Newborns with gestational age below 34 weeks presented lower antibody responses in all three periods. However, gestational age was not important to determine the antibody response in the three periods analyzed. When antibody response was analyzed in terms of birth weight, it was observed that a protective response was present in 75 and 100% of newborns with birth weight < or = 1,500 g and > 1,500 g, respectively. Birth weight was shown to be a relevant factor in determining a protective antibody response at six months of postnatal age. Nonresponders received a fourth vaccine dose and an adequate antibody response was obtained in 100%.
The antibody response of preterm infants was similar to that of term newborns. Hepatitis B vaccination can be initiated on the first day of life in preterm newborns, following the same scheme recommended for term newborns. However, in preterm infants with birth weight less than or equal to 1,500 g, whose antibody response is lower, anti-HB titers should be monitored at nine months of age, or a four-dose vaccination scheme should be provided, with doses on the first day of postnatal life and one, six and nine months later.
研究早产儿对乙肝疫苗的免疫反应。
对35名早产儿和21名足月儿在出生后24小时内以及出生后1个月和6个月时各接种3剂重组乙肝疫苗（剂量为5微克）。
末次接种后3个月时，分别有92.6%的早产儿和100%的足月儿出现保护性抗体反应（抗-HB>10 mUI/mL）（p>0.05）。孕周低于34周的新生儿在所有三个阶段的抗体反应均较低。然而，在分析的三个阶段中，孕周对抗体反应的影响并不显著。按出生体重分析抗体反应时，发现出生体重≤1500克和>1500克的新生儿中，分别有75%和100%出现保护性反应。出生体重是决定出生后6个月时产生保护性抗体反应的一个相关因素。无反应者接种了第4剂疫苗，100%获得了充分的抗体反应。
早产儿的抗体反应与足月儿相似。乙肝疫苗接种可在早产儿出生第一天开始，按照推荐给足月儿的相同方案进行。然而，对于出生体重小于或等于1500克、抗体反应较低的早产儿，应在9个月时监测抗-HB滴度，或者采用四剂接种方案，即在出生第一天、出生后1个月、6个月和9个月各接种一剂。
