Combination vaccines (including polyvalent vaccines) are formulated by combining two or more different pathogen-associated antigens with adjuvants, preservatives, stabilizers, etc. There are two main types of combination vaccines: 1) the first category composes of antigens from different pathogens and can simultaneously prevent diseases caused by multiple pathogens; 2) the second category (polyvalent vaccines) combines different subtypes or serotypes of the same pathogen, which can prevent diseases caused by different antigens of the same pathogen and have a broader risk prevention effect.
With the increase in vaccine types, promoting combination vaccines that can simultaneously prevent multiple diseases has become a global trend. They can reduce the pain of recipients and the workload of vaccination personnel and optimize the utilization of health system resources, providing innovative impetus for research and development institutions. Most studies have confirmed that combination vaccines have immunogenicity and safety equivalent to monovalent vaccines. The World Health Organization has been advocating for the use of combination vaccines to reduce the number of doses administered. Many countries worldwide have included pentavalent and hexavalent vaccines in their immunization plans, and China’s Vaccine Administration Law also explicitly supports the development of new combination vaccines. However, the coverage of combination vaccines among children in China is still insufficient, and the challenges of one child receiving multiple doses of vaccines are prominent.
This evidence pool summarizes the main research findings on pediatric combination vaccines, covering the burden of common vaccine-preventable disease (VPD) among children. It focuses on the advantages, immunogenicity, and safety of combination vaccines for children and summarizes the application experience for children in certain developed and developing countries. The aim is to provide a solid foundation for policymaking and health education activities to optimize immunization programs, improve combination vaccine coverage, and promote population health.