The
host
range
of
HPAIV
H5N1
was
recently
expanded
to
include
ruminants,
particularly
dairy
cattle
in
the
United
States
(US).
Shortly
after,
human
infection
reported
a
worker
Texas
following
exposure
infected
cattle.
Herein,
we
rescued
cattle-origin
influenza
A/bovine/Texas/24-029328-02/2024(H5N1,
rHPbTX)
and
A/Texas/37/2024(H5N1,
rHPhTX)
viruses,
identified
human,
respectively,
their
low
pathogenic
forms,
rLPbTX
rLPhTX,
with
monobasic
HA
cleavage
sites.
Intriguingly,
rHPhTX
replicated
more
efficiently
than
rHPbTX
mammalian
avian
cells.
Still,
variations
PA
NA
proteins
didn't
affect
antiviral
susceptibility
inhibitors.
Unlike
rLPbTX,
both
rLPhTX
exhibited
higher
pathogenicity
efficient
replication
C57BL/6J
mice.
lungs
rHPhTX-infected
mice
produced
inflammatory
cytokines/chemokines
rHPbTX-infected
Our
results
highlight
potential
risk
virus
adaptation
and/or
during
current
multistate/multispecies
outbreak
US.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: April 16, 2024
Abstract
The
global
emergence
of
highly
pathogenic
avian
influenza
(HPAI)
A
(H5N1)
clade
2.3.4.4b
viruses
poses
a
significant
public
health
threat.
Until
March
2024,
no
outbreaks
this
virus
had
occurred
in
domestic
cattle.
We
genetically
characterize
HPAI
from
dairy
cattle
showing
an
abrupt
drop
milk
production.
They
share
nearly
identical
genome
sequences,
forming
new
genotype
B3.13
within
the
clade.
underwent
two
reassortment
events
since
2023
and
exhibit
critical
mutations
HA,
M1,
NS
genes
but
lack
PB2
PB1
genes,
which
enhance
virulence
or
adaptation
to
mammals.
E627K
mutation
human
case
underscores
potential
for
rapid
evolution
post-infection,
highlighting
need
continued
surveillance
monitor
threats.
In
March
2024,
the
emergence
of
highly
pathogenic
avian
influenza
(HPAI)
A
(H5N1)
infections
in
dairy
cattle
was
detected
United
Sates
for
first
time.
We
genetically
characterize
HPAI
viruses
from
showing
an
abrupt
drop
milk
production,
as
well
two
cats,
six
wild
birds,
and
one
skunk.
They
share
nearly
identical
genome
sequences,
forming
a
new
genotype
B3.13
within
2.3.4.4b
clade.
underwent
reassortment
events
since
2023
exhibit
critical
mutations
HA,
M1,
NS
genes
but
lack
PB2
PB1
genes,
which
enhance
virulence
or
adaptation
to
mammals.
The
E627
K
mutation
human
case
associated
with
underscores
potential
rapid
evolution
post
infection,
highlighting
need
continued
surveillance
monitor
public
health
threats.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: May 3, 2024
Abstract
An
outbreak
of
H5N1
highly
pathogenic
influenza
A
virus
(HPIAV)
has
been
detected
in
dairy
cows
the
United
States.
Influenza
(IAV)
is
a
negative-sense,
single-stranded,
RNA
that
not
previously
associated
with
widespread
infection
cattle.
As
such,
cattle
are
an
extremely
under-studied
domestic
IAV
host
species.
receptors
on
cells
sialic
acids
(SAs)
bound
to
galactose
either
α2,3
or
α2,6
linkage.
Human
IAVs
preferentially
bind
SA-α2,6
(human
receptor),
whereas
avian
have
preference
for
(avian
receptor).
The
receptor
can
further
be
divided
into
two
receptors:
isolated
from
chickens
generally
more
tightly
SA-α2,3-Gal-β1,4
(chicken
duck
SA-α2,3-Gal-β1,3
(duck
We
found
all
were
expressed,
different
degree,
mammary
gland,
respiratory
tract,
and
cerebrum
beef
and/or
human
widely
expressed
bovine
chicken
dominated
tract.
In
general,
only
low
expression
was
observed
neurons
cerebrum.
These
results
provide
mechanistic
rationale
high
levels
reported
infected
milk
show
potential
act
as
mixing
vessel
novel
generation.
Graphical
abstract
Created
Biorender.com
EFSA Journal,
Journal Year:
2025,
Volume and Issue:
23(1)
Published: Jan. 1, 2025
A
risk
assessment
framework
was
developed
to
evaluate
the
zoonotic
potential
of
avian
influenza
(AI),
focusing
on
virus
mutations
linked
phenotypic
traits
related
mammalian
adaptation
identified
in
literature.
Virus
sequences
were
screened
for
presence
these
and
their
geographical,
temporal
subtype-specific
trends.
Spillover
events
mammals
(including
humans)
human
seroprevalence
studies
also
reviewed.
Thirty-four
associated
with
five
(increased
receptor
specificity,
haemagglutinin
stability,
neuraminidase
enhanced
polymerase
activity
evasion
innate
immunity)
shortlisted.
AI
viruses
(AIVs)
carrying
multiple
adaptive
belonged
both
low
highly
pathogenic
subtypes,
mainly
A(H9N2),
A(H7N9),
A(H5N6)
A(H3N8),
sporadic
primarily
detected
Asia.
In
EU/EEA,
H5Nx
clade
2.3.4.4b,
which
have
increased
opportunities
evolution
due
widespread
circulation
birds
occasional
cases/outbreaks
mammals,
acquired
highest
number
traits.
Adaptive
traits,
such
as
immune
evasion,
frequently
acquired,
while
receptor-specific
remained
rare.
Globally,
cases
remain
rare,
majority
overall
A(H5N1),
A(H5N6),
A(H7N9)
A(H9N2)
that
are
among
subtypes
tend
a
higher
The
main
drivers
include
host
characteristics,
external
factors
increasing
AIV
exposure
humans
wild
domestic
(e.g.
activities
ecological
factors).
Comprehensive
surveillance
AIVs
targeting
whole
genome
sequencing
animals
is
essential
early
detection
efficient
implementation
control
measures.
All
preparedness,
preventive
measures
must
be
implemented
under
One
Health
tailored
setting
epidemiological
situation;
particular,
monitoring,
biosecurity,
genomic
global
collaboration
critical
mitigating
risks
AIV.
Emerging infectious diseases,
Journal Year:
2024,
Volume and Issue:
30(8)
Published: July 1, 2024
We
report
a
natural
infection
with
Eurasian
highly
pathogenic
avian
influenza
A(H5N1)
clade
2.3.4.4b
virus
in
free-ranging
juvenile
polar
bear
(Ursus
maritimus)
found
dead
North
Slope
Borough,
Alaska,
USA.
Continued
community
and
hunter-based
participation
wildlife
health
surveillance
is
key
to
detecting
emerging
pathogens
the
Arctic.
Cellular and Molecular Immunology,
Journal Year:
2023,
Volume and Issue:
21(2), P. 134 - 143
Published: Dec. 25, 2023
Abstract
Numerous
pathogens
can
infect
the
olfactory
tract,
yet
pandemic
caused
by
SARS-CoV-2
has
strongly
emphasized
importance
of
mucosa
as
an
immune
barrier.
Situated
in
nasal
passages,
is
directly
exposed
to
environment
sense
airborne
odorants;
however,
this
also
means
it
serve
a
direct
route
entry
from
outside
world
into
brain.
As
result,
olfactotropic
infections
have
serious
consequences,
including
dysfunction
system,
CNS
invasion,
dissemination
lower
respiratory
and
transmission
between
individuals.
Recent
research
shown
that
distinctive
response
needed
protect
neuronal
mucosal
tissue.
A
better
understanding
innate,
adaptive,
structural
barriers
develop
effective
therapeutics
vaccines
against
microbes
such
SARS-CoV-2.
Here,
we
summarize
ramifications
infection
mucosa,
review
subsequent
response,
discuss
important
areas
future
for
immunity
infectious
disease.
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: Aug. 19, 2024
Abstract
The
highly
pathogenic
avian
influenza
(HPAI)
A(H5N1)
clade
2.3.4.4b
viruses,
responsible
for
the
current
outbreak
in
dairy
cows
United
States,
pose
a
significant
animal
and
public
health
threat.
In
this
study,
we
compared
disease
progression
pathology
of
three
recent
isolates
derived
from
cow,
mountain
lion,
mink
to
human
HPAI
isolate
Vietnam
mice.
Inoculation
C57BL/6J
BALB/c
mice
with
all
four
resulted
comparable
levels
virus
replication
lung
inducing
severe
respiratory
disease.
infected
bovine
also
developed
high
titers
brain,
resulting
pro-inflammatory
cytokine
response
neurologic
Our
findings
suggest
possesses
enhanced
neuroinvasive/neurovirulent
properties
causing
fatal
The
newly
emerged
avian
influenza
A
H5N1
Clade
2.3.4.4b
can
infect
dairy
cows
and
shed
live
virus
in
their
milk.
Sporadic
cattle-to-human
infections
have
been
reported,
highlighting
the
urgent
need
to
understand
its
pathogenesis
mammals.
Using
both
non-lactating
lactating
BALB/c
mice,
we
examined
viral
tissue
tropism,
histopathological
damages,
host
immune
responses
upon
intranasal
inoculation
with
a
reverse-genetic
constructed
based
on
A/dairy
cattle/Texas/24-008749-003/2024
(Cattle-H5N1)
comparing
an
older
reference
1
virus,
A/Vietnam/1194/2004
(VNM1194-H5N1).
Cattle-H5N1
was
highly
lethal
mice
(mLD50
=1.48PFU)
broad
tropism
produced
higher
titer
respiratory
multiple
extrapulmonary
organs
than
VNM1194-H5N1.
In
lungs,
infection
of
airway
epithelium,
type
II
pneumocytes
CD45+
cells
were
at
frequency
those
VNM1194-H5N1-infected
resulting
severe
epithelial
destruction
diffuse
alveolar
damage
accompanied
by
elevated
lung
serum
pro-inflammatory
cytokine/chemokines.
Although
viruses
showed
mammary
gland
more
severely
damaged
after
abundant
antigens
expression
glandular
cells,
associated
fat
lymphoid
tissues.
Furthermore,
suckling
co-housed
infected
virus-positive
(7/30
pups)
Brains
heavily
Cattle-H5N1,
neurological
signs
such
as
body-rolling/spinning,
trembling
and/or
limb
paralysis
seen
only
mice.
spleen
infection,
which
massive
antigen
apoptosis
splenic
atrophy,
concluding
that
is
virulent
Journal of General Virology,
Journal Year:
2025,
Volume and Issue:
106(4)
Published: April 25, 2025
The
high
pathogenicity
avian
influenza
virus
H5N1,
which
first
emerged
in
the
winter
of
2021,
has
resulted
multiple
outbreaks
across
American
continent
through
summer
2023
and
they
continue
based
on
early
2025
records,
presenting
significant
challenges
for
global
health
food
security.
viruses
causing
belong
to
clade
2.3.4.4b,
are
descendants
lineage
A/Goose/Guangdong/1/1996
(Gs/Gd)
genetic
reassortments
with
several
low
present
populations
Anseriformes
Charadriiformes
orders.
This
review
addresses
these
issues
by
thoroughly
analysing
available
epidemiological
databases
specialized
literature
reviews.
project
explores
mechanisms
behind
resurgence
H5N1
virus.
It
provides
a
comprehensive
overview
origin,
timeline
factors
contributing
its
prevalence
among
wild
bird
continent.