Table 1.
Downstream effects of vaccination.
| Observation | Potential mechanism | |
|---|---|---|
| Vaccinia virus60,61 |
• Reduced all-cause mortality • Protection against melanoma and non-Hodgkin lymphoma • Anecdotal associations with improvements in rash, syphilis, chronic diseases • Reduced nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae |
• Upregulation of monocyte/macrophage markers with increased expression of pro-inflammatory cytokines and of genes involved in cell metabolism and trained immunity |
| BCG48,59,60 |
Reduced all-cause mortality • Reduced sepsis, respiratory infections, respiratory syncytial virus infection, and fever in low birth weight infants • Enhanced antibody responses to other vaccines • Effective treatment against bladder cancer • Enhanced resistance to bacterial, fungal, and viral infections in mice • Prevention of development of type 1 diabetes • Increased susceptibility to Salmonella typhi or Eberthella typhosa |
• Lymphocyte-mediated effects including CD4+ and CD8+ cells modifications leading to enhanced Th1/Th17 responses during non-related infections • Increased activity of NK cells • NOD2-mediated epigenetic re-programing of H3K4me3 with enhanced transcriptional activity in pro-inflammatory promoter regions |
| Measles-containing vaccine48,49 |
• Reduced all-cause mortality • Reduced nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae |
• Transient suppression of lymphoproliferative responses but increased non-specific cytokine production (IL-6, TNFɑ, and IFNƴ) suggesting increased innate immune responses |
| Yellow fever vaccine59,60 | • Reduced all-cause mortality | • Activation of mTOR with evidence of changes to metabolism and upregulation of histone methylation. |
| Rotavirus vaccine61,105,106 |
• Reduced risk of developing autoimmune diseases including type 1 diabetes and celiac disease in the period after vaccination • Reduced risk of seizure |
• Not known |
| Formalin-activated respiratory syncytial virus vaccine62,106 | • Enhanced respiratory disease on re-exposure | • Excessive Th2-biased response |