Influenza Flashcards
influenza is a
negative ssRNA enveloped virus
incubation period
1-4 days
people are contagious ___ day(s) before symptoms and up to ___ day(s) after developing symptoms
1; 5-7
four types of influenza:
a,b,c,d
influenza a
most virulent to humans; many types
influenza b
almost exclusively humans; some seals and ferrets
influenza c
humans, dogs, pigs
influenza D
cows
Influenza A subtypes
H1N1 and H5N1
influenza b lineages
Victoria and yamagata
influenza is classified by
HA and NA; then by subtype
HA
receptor binding, membrane fusion
NA
viral release cleaves sialic acids, probably a role in viral entry
influenza replication cycle
the HA binds to the receptor 2,3 or 2,6 (human)-sialic acids. The virus gets endocytosed, pH of fusion occurs, then the RNA gets imported into the nucleus. It is synthesized and then replicated, then is assembled at the cell membrane. The 8 segments of RNA are entered into the virus and are then cleaved by budding
who should get the vaccine and when?
people 65 and older; once a season in September or October
Can individuals with egg allergies get the vaccine?
Can get vaccinated with egg allergy
what is the composition of this year’s influenza vaccine?
4 viruses, 2 AS (H1N1 and H3N1) and 2 BS (1 of each)
can one get an influenza vaccine and a COVID-19 booster in the same visit?
Yes, at the same time as long as you are qualified for both and supposed to get on different arms
what type of influenza vaccine should those 65+ get?
a high dose vaccine
what are some complications in children from flu?
more severe infections
what is the special instruction for children 6mo-8yrs?
get 2 doses
what is flu vaccination by jet injector?
a needleless vaccine that shoots vapors through the skin
who should not get the nasal spray vaccine?
those immunocompromised, have asthma, those pregnant
how is the recombinant flu vaccine made?
they are created synthetically. They obtain the gene with the instructions for creating a surface protein (HA) found on the influenza virus. This protein triggers the immune system so antibodies are released and target the virus. It is then combined with a baculovirus which helps transport the instructions for making the HA antigen into a host cell. Once it enters a host cell it instructs the cells to rapidly produce the HA antigen
influenza can jump from species to species in one of three ways
direct jump, adaptation, and reassortment
direct jump
animal to person
adaptation
other animals can infect other animals and mutate
reassortment
can have cells with multiple viruses and reassort to a new virus
H5N1 disease symptoms
severe respiratory illness, neurological changes, 53% death
H5N1
more in the lower respiratory; uses 2,3-SA; spreads slowly; often fatal
H1N1
typically upper respiratory; uses 2,6-SA; easily spread; rarely fatal
bird flu is normally spread through ___
direct contact
the search for a universal vaccine
peak 2-4 weeks, decrease by 50%, stable for 2-3 years
new universal candidate
inactivated avian; 2 doses
co-infections
detected at the same time (not sure)
secondary infections
usually a person got infected after the first (detect)
superinfection
definitely have the first and then got the second (negative then got at a different date)
for secondary and confections
morbidity and mortality rates increase
influenza secondary bacterial infection is commonly ____ of ____
streptococcus pneumoniae; haemophilus influenzae
streptococcus pneumoniae is spread by
person to person
SP symptoms
fever, pneumonia, meningitis, hearing loss, brain damage
SP vaccine
<2 or >65; other health conditions
haemophilus influenzae symptoms
middle ear infections, sinus infections, bronchitis, pneumonia, meningitis
