Related Experiment Videos
Neonatal immunization: response to Haemophilus influenzae type b-tetanus toxoid conjugate vaccine
Insights
Neonatal Haemophilus influenzae type b (Hib) conjugate vaccine (PRP-T) is safe and well-tolerated. Early administration primes the immune system, providing lasting protection against Hib infections.
Area of Science:
- Pediatric Infectious Diseases
- Immunology
- Vaccinology
Background:
- Haemophilus influenzae type b (Hib) poses a significant threat to infants.
- Neonatal immunization strategies are crucial for early protection.
- Assessing the immunogenicity and tolerability of early vaccine administration is vital.
Purpose of the Study:
- To evaluate the safety and immunogenicity of the Haemophilus influenzae type b (Hib) conjugate vaccine (PRP-T) when administered during the neonatal period.
- To compare immune responses to different vaccination schedules.
- To investigate potential immunologic tolerance following neonatal vaccination.
Main Methods:
- A study involving 120 neonates receiving PRP-T at 2 days of age, followed by different schedules at 4 months and a booster at 14 months.
- Comparison of anti-Hib polysaccharide (PS) concentrations with control groups.
- Monitoring for adverse reactions and assessing antibody levels over time.
Main Results:
- The PRP-T vaccine was safe and well-tolerated in neonates, with no serious adverse reactions.
- Neonatal vaccination with PRP-T induced a significant antibody response, indicating immunologic priming.
- Vaccination schedules including a neonatal dose showed higher antibody concentrations at 14 months compared to later-only vaccination.
Conclusions:
- Neonatal immunization with PRP-T is a safe and effective strategy for Haemophilus influenzae type b (Hib) prevention.
- Early vaccination primes the immune system, leading to sustained antibody levels.
- Further research in higher-risk populations is warranted to explore the full potential of neonatal Hib vaccination.
Objective:
To study the immunogenicity and tolerability of Haemophilus influenzae type b (Hib) conjugate vaccine administered in the neonatal period.
Design:
Hib capsular polysaccharide (PS)-tetanus toxoid conjugate vaccine (PRP-T) was given to 120 neonates at 2 days of age, followed by PRP-T or the Hib PS vaccine at 4 months and a PRP-T booster at 14 months. Their anti-Hib PS concentrations were compared with those in children receiving PRP-T at 2 and 4 months or at 4 months.
Results:
No serious adverse reactions were noted. The geometric mean concentration of anti-Hib PS at the age of 2 days was 0.34 micrograms/mL and at 4 months was 0.12 micrograms/mL. This was significantly more than the concentration in unimmunized infants at this age and 3.5 times more than expected, taking into account the natural decay of transplacentally acquired antibodies. Such a response was not seen in infants with a high (greater than 3.0 micrograms/mL) neonatal antibody concentration. The PRP-T vaccine given at 4 months elicited an antibody response in all infants and Hib PS in 62%, indicating immunologic priming. At 14 months, a higher percentage of the infants who had received PRP-T at 2 days and 4 months than of those who had received PRP-T at 4 months only had anti-Hib PS concentrations greater than 0.15 micrograms/mL. All infants responded well to the booster at 14 months. There was no evidence of immunologic tolerance.
Conclusions:
Neonatal immunization with PRP-T was safe and well tolerated in Finnish infants, and it would be worthwhile to further study its effects in higher risk populations.