BCG vaccination and COVID-19
BCG vaccination & COVID-19
The component (s) of the innate immune system that include neutrophils & macrophages, are the 1st line of defense mechanism against
various newly-developed pathogens for which the human immune system have little or no previous immunity. Recent large-scaled epidemiological reports declare
that many countries in which Bacille Calmette-Guerin (BCG) vaccination is widely spread have a
lower mortality rate (MR) from COVID-19.
This observation can be explained via the so-called phenomenon "trained immunity,"
in which macrophages &
neutrophils perform epigenetic changes in response to infection, vaccination, or microbial components that modify their response to the subsequent unrelated pathogens. Despite the short-life spans of these cells, recent researches in this concept have revealed
that similar changes may occur in long-lived
bone marrow precursors, leading
to a mechanism for lasting "memory" within the innate
immune system basal components.
v Covián C, Retamal-Díaz A, Bueno SM, Kalergis
AM. Could BCG Vaccination Induce Protective Trained Immunity for SARS-CoV-2?
Front Immunol 2020; 11:970.
v Escobar LE, Molina-Cruz A, Barillas-Mury C.
BCG vaccine protection from severe coronavirus disease 2019 (COVID-19). Proc
Natl Acad Sci U S A 2020; 117:17720
v de Laval B, Maurizio J, Kandalla PK, et al.
C/EBPβ-Dependent Epigenetic Memory Induces Trained Immunity in Hematopoietic
Stem Cells. Cell Stem Cell 2020; 26:793
Normalization of BP
in children diagnosed with hypertension
The current definition of a high blood pressure (BP) & hypertension (HT) in children rely primarily
on repeating BP measurement at 3 separate clinical encounters. However, in a retrospective, multicenter cohort study using electronic medical registry data from aproximately 400,000 children undergoing the routine BP measuring at primary care visits, children who’re mostly met the criteria for either HT (n = 1881) or raised BP (n = 2144) based on ≥3 BP measuring reported
over 36 mo hd normal BP during a second
consecutive 36-mo period (50 % of individuals with a prior dgx of HT; 70 % of
individuals with a prior Dgx of raised BP). A noticeable limitations may include
the small number of children in the entire cohort who hd ≥3
longitudinal BP readings in addition to the difficulty to verify whether BP read
were performed appropriately and what were the interventions (eg, lifestyle changes) have been implemented. However, if further
studies recognize these results, the diagnostic criteria for pediatric HT may need to be modified to include: BP monitoring over a longer
time frame before a diagnosis has been settled.
Kaelber DC, Localio AR, Ross M, et al. Persistent Hypertension in Children and Adolescents: A 6-Year Cohort Study. Pediatrics 2020; 146.
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