Background: The introduction of new vaccines has been delayed in some countries in the Asia-Pacific region, which has led to delays in accessing vaccines for target patients. However, the approval lag of vaccines in the Asia-Pacific region has not been assessed. The objective of this study is to assess the availability and approval lag of vaccines in Asia-Pacific countries and compare them among Asia-Pacific countries, the United States (US), and Europe (EU). Methods: The information on vaccines prequalified by the World Health Organization (WHO) between 2010 and 2019 was obtained primarily from the WHO website. The date of approval of the WHO prequalified vaccine in Australia, India, South Korea, Thailand, Singapore, Malaysia, the US, and EU was retrieved from the official website of national regulatory agencies. The vaccines were divided into two groups based on their first approval pathway, that is, vaccines that were first approved by SRA (Stringent Regulatory Authority including the US, EU, and WHO) and those that were first approved by non-SRA. The absolute approval lag represented the availability of the vaccine. Relative approval lag represented the lag time between the approval date of the country of interest and the first global approval date and was measured as the median approval lag. A Mann−Whitney U test was used to examine statistical differences between relative approval lag between the SRA first and the non-SRA first groups. Results: A total of 92 vaccines were prequalified by the WHO between 2010 and 2019, but only 61 vaccines were included in the analysis. Over 50% of vaccines were first licensed by non-SRAs. Of all the WHO-prequalified vaccines, the median approval lag in the ASEAN countries in this study was longer than those in the US and EU, with a median of 30 months in Australia, 15 months in South Korea, 52 months in Thailand, and 23 months in Singapore, compared to 0 months in the US and EU. The differences in approval lags between SRA first vaccines and non-SRA first vaccines were statistically significant in South Korea and Thailand (p < 0.05). Conclusions: The approval lag of vaccines was observed in the Asia-Pacific region, indicating a gap between the Asia-pacific region and the US and EU in regard to access to new vaccines. Future studies need to analyze the background factors related to the gap in availability and vaccine approval lag in the Asia-Pacific region and assess the impact of vaccine approval lag in the region.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.