Beyond adaptive immunity: induction of trained immunity by COVID-19 adenoviral vaccines

No evidence of durable trained immunity after two doses of adenovirus-vectored or mRNA COVID-19 vaccines

“…( D ) Shown is t-distributed stochastic neighbor embedding ( t -SNE) analysis of ATAC-Seq data before and after vaccination. ( E ) Mean chromatin accessibility and ( F ) representative plots of peaks ± 5 kb of the TSS of selected genes previously shown to have altered accessibility in monocytes following BNT162b2 or BCG vaccination ( 4 , 6 ). CPM, counts per million.…”

“…In contrast, Yamaguchi et al ( 3 ) reported only transient epigenomic and transcriptomic changes in monocytes collected from five individuals following two doses of the BNT162b2 (Pfizer/BioNTech) mRNA vaccine. These findings suggest that ChAdOx1-S but not BNT162b2 vaccination induces TI, which could have important implications for the use of COVID-19 vaccines globally ( 4 ).…”

“…Natalie E. Stevens, 1,2 Feargal J. Ryan, 1,2 Nicole L. Messina, 3,4 Stephen J. Blake, 1,2 Todd S. Norton, 1 Susie Germano, 3 Jane James, 1 Georgina L. Eden, 1 Yee C. Tee, 1,2 Miriam A. Lynn, 1,2 Rochelle Botten, 1 Simone E. Barry, 5 Nigel Curtis, 3,4 and David J. No evidence of durable trained immunity after two doses of adenovirus-vectored or mRNA COVID-19 vaccines…”

Influenza vaccine effectiveness against hospitalized SARS-CoV-2 infection

“…There has been some speculation that the flu shot may also provide some protection against SARS-CoV-2 infection and COVID-19 disease[3]. Researchers have proposed several mechanisms, such as trained immunity[4][5][6][7][8][9][10][11], increased cytokine production[12][13], and viral interference[14], to explain how heterologous or nonspecific effects (NSEs) induced by available non–SARS-CoV-2 vaccines could potentially prevent SARS-CoV-2 infection and reduce COVID-19 disease. [15]…”

Translating Animal Studies to Human Disease: Language Matters*

“…Most of the laboratory data included by Vermeersch et al (1)—cytokine levels, histologic evidence of inflammation, immune cell populations, and phagocytic capacity of alveolar macrophages—examine the immune system. Indeed, much of the discussion centers on vagaries of immune cell function (e.g., regulatory T cells, aka γδT cells, and αβT cells) and concepts that might be unfamiliar to clinicians (e.g., “trained immunity” [10]). Ultimately, the authors sought evidence of an altered host IMMUNE response—and equated that response with the entirety of the host response to infection.…”