The article concerns a clinical trial investigating the safety, tolerability, and immunogenicity of an experimental 31-valent pneumococcal conjugate vaccine (VAX-31) in healthy adults aged 50 years and older from the USA. It was a randomized clinical trial in phase 1/2, double-blinded, actively controlled, and parallel-group designed to determine the optimal dose. The original article was published in The Lancet Infectious Diseases online on March 18, 2026. This notice represents a correction to the appendix of the original article, which was made on April 14, 2026. The specific details of the correction are not specified in the text.