In- and exclusion criteria for fine-tuning the dataset, inspired by [16].

aPreclinical Phase;
bHuman clinical trials Phase One;
cHuman clinical trials Phase Two;
dHuman clinical trials Phase Three;
eRegulatory submission to allow market entry;
fProjects discontinued for any reason during any stage of the following stages of vaccine development in PC, PI, PII and PIII;
gMarket phase;
hPost-marketing, also known as human clinical trials phase four;
iNo information available;
jFailed or terminated vaccine products. In other words, products that have received regulatory market approval, but have been withdrawn from the market for any reason.