Optimising DTwP-containing vaccine infant immunisation schedules (OptImms) - a protocol for two parallel, open-label,...

Area of Science:

• Pediatric Infectious Diseases
• Vaccinology
• Public Health Policy

Background:

• Universal childhood immunisation is crucial for preventive medicine, with the WHO recommending the diphtheria-tetanus-pertussis (DTP) vaccine at specific ages.
• The increasing introduction of new vaccines leads to crowded infant immunization schedules globally, with over 17 DTP-containing vaccine schedules in use.
• The OptImms trial aims to assess if antibody titres can be maintained with adjusted schedules, creating space for new vaccines.

Purpose of the Study:

• To evaluate the immunogenicity of modified infant vaccination schedules.
• To determine if antibody titres against pertussis and other antigens can be maintained with adjusted schedules.
• To inform policy decisions on optimizing childhood immunization schedules.

Main Methods:

• Two randomized, five-arm, non-inferiority clinical trials conducted in Nepal and Uganda.
• Infants randomized to different DTwP vaccination schedules (start age, doses, spacing) and booster timing (9 vs. 12 months).
• Primary outcome: anti-pertussis toxin IgG antibodies at booster dose; secondary outcomes: other antigen antibodies and safety.

Main Results:

• The study is designed to assess antibody titres against pertussis and other vaccine antigens.
• Safety data for the modified vaccination schedules will be collected and analyzed.
• The primary outcome measure is anti-pertussis toxin IgG antibodies at the time of the booster dose.

Conclusions:

• The trial's findings will provide crucial data for policy-making regarding vaccination schedules.
• Streamlining childhood immunization schedules can facilitate the integration of new vaccines.
• Evidence generated will support optimized public health strategies for child immunization.