New Insights into Influenza Vaccines from South Korea

Strategic Insights -

Researchers in South Korea have recently published data on cell culture-derived influenza vaccines, specifically the SKYCellflu quadrivalent vaccine. The study aimed to assess the safety and influenza infections in children aged 6-35 months following SKYCellflu vaccination. The prospective cohort, non-interventional, multi-center post-marketing surveillance study was conducted from 2020 to 2024, with a focus on the 2023-2024 influenza season.

Key Takeaways:

  • The SKYCellflu quadrivalent vaccine has been in use since 2015, and this study aimed to assess its safety and influenza infections in children aged 6-35 months in South Korea.
  • Among 333 safety set participants, 54.4% reported at least one adverse event (AE), with most being mild to moderate.
  • The cumulative incidence of influenza infections among 247 ad hoc subsets was 4.5%, and the incidence rate was 1.3 per 100 person-months (95% CI, 0.7-2.4) during the 2023-2024 influenza season.
  • The two-dose regimen in vaccine-naive infants aged 6-11 months showed a lower cumulative incidence of influenza infection rate (0.8% vs. 3.8%) and incidence rate (0.3 vs. 0.9 per 100 person-months) than the one-dose group (3.8%).
  • No influenza-related hospitalizations occurred within the ad hoc subset.
  • The study demonstrated a tolerable safety profile and the pattern of influenza infections following SKYCellflu vaccination.
  • The two-dose regimen was associated with a lower incidence of influenza infections, suggesting potential benefits in enhancing protection among infants aged 6-11 months.

Statistics:

  • 54.4% of participants reported at least one adverse event (AE) within 28 days post-vaccination.
  • The cumulative incidence of influenza infections was 4.5% among 247 ad hoc subsets.
  • The incidence rate was 1.3 per 100 person-months (95% CI, 0.7-2.4) during the 2023-2024 influenza season.
  • The two-dose regimen showed a lower cumulative incidence of influenza infection rate (0.8% vs. 3.8%) among infants aged 6-11 months.

Sources:

  • Safety and Influenza Infections in Children Aged 6-35 Months Receiving Cell Culture-Derived Inactivated Quadrivalent Influenza Vaccine During the 2023-2024 Influenza Season in South Korea. Vaccines, 2025,13(5):501. (Vaccines - http://www.mdpi.com/journal/vaccines)
  • NewsRx. Research from Medical Affairs Provide New Insights into Influenza Vaccines (Safety and Influenza Infections in Children Aged 6-35 Months Receiving Cell Culture-Derived Inactivated Quadrivalent Influenza Vaccine During the 2023-2024 Influenza ...). Vaccine Weekly. June 11, 2025; p 5187.