Symptoms after primary immunisation with DTP and with DT vaccine

Area of Science:

• Immunology
• Pediatrics
• Vaccinology

Background:

• Routine infant immunizations are crucial for public health.
• Understanding vaccine safety profiles is essential for healthcare providers and parents.
• Diphtheria/tetanus/pertussis (DTP) and diphtheria/tetanus (DT) vaccines are commonly administered.

Purpose of the Study:

• To compare post-vaccination symptoms following routine primary immunization with adsorbed DTP and DT vaccines.
• To evaluate the frequency of specific adverse events associated with DTP and DT vaccines.
• To assess the impact of vaccine formulation (adsorbed vs. plain) on post-vaccination symptoms.

Main Methods:

• A comparative study involving 6004 infants receiving adsorbed DTP vaccine and 4024 infants receiving adsorbed DT vaccine.
• Systematic monitoring and recording of post-vaccination symptoms after each vaccine dose.
• Inclusion of over 1000 doses of plain DTP vaccine to assess its safety profile.

Main Results:

• Adsorbed DTP was associated with a small increase in crying, screaming, and feverishness compared to adsorbed DT.
• Convulsions, pallor/cyanosis with limpness, and local reactions occurred with similar frequency for both adsorbed vaccines.
• A significant increase in local reactions was observed after the third dose for both adsorbed DTP and DT vaccines.
• Plain DTP vaccine resulted in a higher incidence of post-vaccination symptoms compared to the adsorbed preparations.

Conclusions:

• Adsorbed DTP and DT vaccines have similar safety profiles for most adverse events, with minor differences in febrile and crying responses.
• Local reactions increase with subsequent doses of adsorbed vaccines.
• Plain DTP vaccines may be associated with a higher burden of post-vaccination symptoms compared to adsorbed formulations, warranting further investigation.