MSD Korea said its new 15-valent pneumococcal protein conjugate vaccine, Vaxneuvance, will be available for free at hospitals and clinics nationwide starting Monday as part of the National Immunization Program (NIP) for children.

Vaxneuvance is indicated for preventing invasive disease and pneumonia caused by 15 pneumococcal serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F) in children six weeks of age and older, the company explained.

Integrating MSD's 40 years of pneumococcal vaccine development expertise, Vaxnuevance is the first new pneumococcal protein conjugate vaccine in 13 years. It expands protection to include the 13 serotypes shared with PCV13 plus two new serotypes, 22F and 33F, the leading causes of invasive pneumococcal disease, MSD Korea said.

With recent reports of seroconversion, an increase in pneumococcal disease caused by serotypes not included in existing vaccines, Vaxneuvance is a preventive option that aligns with the current pneumococcal disease epidemic, it added.

According to MSD Korea, the immunogenicity of the individual serotypes in the vaccine is as important as the coverage in vaccine selection criteria, as immunogenicity can predict the vaccine's efficacy. That explains why the World Health Organization (WHO) has issued recommendations for standardized immunogenicity testing of pneumococcal vaccines.

In this regard, Vaxneuvance is expected to be an effective pneumococcal vaccine option because 12 clinical studies in adults, infants, children, and adolescents have confirmed equivalent levels of immunogenicity across all 15 serotypes included in the vaccine. These include non-inferiority of immunogenicity against 13 shared serotypes compared to conventional PCV13 and superior immunogenicity against unique serotypes 22F and 33F1.

In addition, serotype 3 continues to be reported to cause fatal invasive disease in children even after conventional pneumococcal vaccination6. Thus, there is an unmet need for protection against this serotype, and Vaxneuvance has confirmed superior immunogenicity against serotype 3 compared to PCV131.

NIP is available for all children two months to five years of age, including those who have not yet received a pneumococcal protein conjugate vaccine or those who have started but have not completed the schedule. Clinical studies in children have confirmed that Vaxneuvance can be cross-immunized with conventional PCV13, so even if a child has received one or more doses of conventional PCV13, the remaining recommended doses can be cross-immunized with Vaxneuvance.

"Although the causative virus of pneumococcal disease does not change as fast as other infectious diseases, such as Covid-19, changes in the causative agents have recently been reported globally,” said Kim Su-jeong, Country Medical Director at MSD Korea. “Therefore, it is important to develop a vaccine with broader protection by considering the new causative serotypes and the virulence of the disease caused by them. In addition, immunogenicity, which indicates the effectiveness of a vaccine, is also important, and Vaxneuvance has confirmed the immunogenicity of each of the 15 serotypes included in the vaccine through various clinical studies.”

Based on this, MSD Korea will strive to supply Vaxneuvance in Korea as it has been introduced to the pediatric NIP and create an effective pneumococcal prevention environment for the entire family, including children and adults, Kim added.