Infection History Determines Susceptibility to Unrelated Diseases

Abstract

Epidemiological data suggest that previous infections can alter an individual's susceptibility to unrelated diseases. Nevertheless, the underlying mechanisms are not completely understood. Substantial research efforts have expanded the classical concept of immune memory to also include long‐lasting changes in innate immunity and antigen‐independent reactivation of adaptive immunity. Collectively, these processes provide possible explanations on how acute infections might induce long‐term changes that also affect immunity to unrelated diseases. Here, we review lasting changes the immune compartment undergoes upon infection and how infection experience alters the responsiveness of immune cells towards universal signals. This heightened state of alert enhances the ability of the immune system to combat even unrelated infections but may also increase susceptibility to autoimmunity. At the same time, infection‐induced changes in the regulatory compartment may dampen subsequent immune responses and promote pathogen persistence. The concepts presented here outline how infection‐induced changes in the immune system may affect human health.

Vaccine- and natural infection-induced mechanisms that could modulate vaccine safety

“… Antibody-Dependent Enhancement (where enhanced virus entry and replication in a number of cell types is enabled by antibodies) [ [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] ]; Intrinsic Antibody-Dependent Enhancement (where non-neutralizing antibodies raised by natural infection with one virus may enhance infection with a different virus) [ [55] , [56] , [57] , [58] , [59] , [60] , [61] ]; Immune Enhancement (enhancement of secondary infections via immune interactions) [ [62] , [63] , [64] , [65] ]; Cross-reactivity (an antibody raised against one specific antigen has a competing high affinity toward a different antigen.) [ 66 , 67 ] Cross-Infection Enhancement (infection enhancement of one virus by antibodies from another virus) [ 68 , 69 ] Vaccine-associated Virus Interference (where vaccinated individuals may be at increased risk for other respiratory viruses because they do not receive the non-specific immunity associated with natural infection) [ [70] , [71] , [72] , [73] , [74] , [75] ]; Vaccine-Associated Imprinting Reduction (where vaccinations could also reduce the benefits of ‘imprinting’, a protection conferred upon children who experienced infection at an early age) [ 76 , 77 ]; Non-Specific Vaccine Effects on Immune System (where previous infections can alter an individual's susceptibility to unrelated diseases) [ 78 , 79 ]; Impact of Infection Route on Immune System (where immune protection can be influenced by the route of exposure/delivery) [ [80] , [81] , [82] ]; ...…”

“…Non-Specific Vaccine Effects on Immune System (where previous infections can alter an individual's susceptibility to unrelated diseases) [ 78 , 79 ];…”

Goat Immunity to Helminthes

“…Its expression results in Cyclin and other growth factors. In a recent documentation that there is a universal reduction of CD 4 T cells which is one of the hallmark of helminthes infection [141,151].…”

Emphasizing the link between blood types in multi-ethnic disparities and COVID-19 infection in Makkah, Saudi Arabia

“…12 Therefore, several studies have discussed the association of ABO blood grouping and host susceptibility to infectious diseases such as Severe Acute Respiratory Syndrome, symptomatic West Nile Virus, Human Immunodeficiency Virus )HIV(, Hepatitis B, Norwalk virus1, Helicobacter pylori, and Plasmodium falciparum. 11,13 Previous studies have found that this association is because ABO antibodies are a component of the innate immune system that protects against certain bacteria, parasites and enveloped viruses. 14 In addition, blood antigens are considered to be receptors for immune and inflammation responses, which means that a biological association between ABO blood groups and HBV infection, for example, probably exists.…”