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[Immune response of preterm infants to hepatitis B vaccine administered within 24 hours after birth]
Lilian S R Sadeck1, José L A Ramos
1Departmento de Pediatria, FMUSP, Sao Paulo, SP.
Insights
Preterm infants show a strong immune response to hepatitis B vaccination, similar to full-term infants. Early vaccination on the first day of life is recommended for preterm newborns.
Area of Science:
- Immunology
- Pediatrics
- Vaccinology
Background:
- Hepatitis B infection poses a significant risk to newborns.
- Premature infants may have altered immune responses compared to full-term infants.
Purpose of the Study:
- To evaluate the immunogenicity of a hepatitis B vaccine in preterm infants.
- To compare the antibody response in preterm versus full-term infants.
Main Methods:
- Three doses of recombinant hepatitis B vaccine (5 µg) were given to preterm and full-term infants within 24 hours of birth, and at 1 and 6 months.
- Antibody titers (anti-HB) were measured to assess protective immune response.
Main Results:
- 92.6% of preterm infants achieved protective antibody levels (anti-HB > 10 mIU/mL) after vaccination, comparable to 100% in full-term infants.
- Lower birth weight (< or = 1,500 g) was associated with a reduced antibody response, while gestational age below 34 weeks showed varied responses.
- A fourth vaccine dose successfully induced protective immunity in all non-responders.
Conclusions:
- Hepatitis B vaccination is effective in preterm infants, with similar antibody responses to term newborns.
- Routine hepatitis B vaccination can commence on the first day of life for preterm infants.
- Preterm infants with birth weight <= 1,500 g require monitoring of anti-HB titers at nine months or a four-dose vaccination schedule.
Objective:
To investigate the immune response of preterm infants to hepatitis B vaccination.
Methods:
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.
Results:
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%.
Conclusion:
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.
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