Genetic Sequencing of a Bacterial Pneumonia Vaccine Produced in 1916

In this study, we obtained and isolated DNA from two ampules of a mixed bacterial influenza vaccine produced in 1916, which were labeled as containing killed B. influenzae, Pneumococci, and Streptococcus Pyogenes. We found that the amount of recoverable DNA from these century-old vaccine ampules was limited. After performing Whole Genome Amplification (WGA), Illumina sequencing libraries were constructed and deep-sequencing was performed. The sequencing results revealed minimal detectable S. pneumoniae DNA. The first ampule contained predominantly H. influenzae DNA, while the second vial primarily contained Enterococcus faecium DNA, in addition to S. pyogenes DNA. Consensus genomes for H. influenzae, S. pyogenes, and Enterococcus faecium were assembled based on the obtained sequences. Serotype identification, phylogenetic analysis, and antibiotic resistance gene analyses were conducted using the consensus bacterial genomes. This study represents the first sequencing effort to analyze bacterial pneumonia vaccines produced around the timeframe of the 1918 influenza pandemic.