a glycoprotein that attaches sialic acid sugars on surface of epithelial cells. (typically nose,throat, and lungs)
What does Haemagglutinin play a critical role in?
fusion on viral envelope--leadings to injection of viral RNA
Haemagglutinin is a protein for strain typing what?
H1 of H1N1 of influenza
What is neuraminidase (aka N/NA) ?
-a class of enzymes that cleave glycosidic linkages and digest sialic acid on surfaces of cells.
What does neuraminidase allow?
allow for detachment of newly formed virus, making it easier for progeny virions to diffuse away from cell once they exit.
Neuroaminidase are also involved in what?
-penetration of mucus layers of respiratory tract (strains of virus aka these proteins (NI or H1N1)
What's other names for "The common cold?"
-nasopharyngitis, rhinopharyngitis, acute coryza, or a cold
What is the common cold?
a viral infectious disease of upper respiratory tract which affects the nose (primarily)
What are the symptoms of the common cold?
fever (usually resolve in 7-10 days)
(some symptoms last 3 wks
-over 200 viruses are implicated in cause of common cold;rhinoviruses(most common).
How are symptoms created?
body's immune response to infection rather than tissue destruction by viruses themselves.
Is there a cure for the common cold?
no, but symptoms can be treated.
What are the diagnosis of influenza?
-enzyme immuno assay (ELISA)
-Immunofluoresence DFA Antibody Straining
-Reverse Transcriptase PCR (RT-PCR)
How is influenza treated?
--Neuraminidase inhibitors are a class of antiviral drug that target neuroaminidase, which prevents release (budding) and progeny of newly formed viruses from cell.
They do not kill virus NOR change immune response of host
What does amantidine and rimantidine prevent?
prevent protein cost being stripped away releasing nucleic acid.
What does Amantidine and Rimantidine target?
-highed conserved M2 protein
M2 protein acts as ion channel; an imp component in uncoating of virus; which prevents entry into host cells,
Amantidine and Rimantidine are specific for __________ since type ___ do not contain an M2 Protein.
-specific for type A influenza
since type B do not contain M2 protein
Amantidine and Rimantidine are easier and cheaper to manufacture compared to what?
What are the immune responses of Amantidine and Rimantidine?
following infection: rapid humoral response and antibodies produced to viral hemagglutinin
blocks virus binding to the target cell
response peaks after several days and lasts for about 6 mths.
prevents reinfection by the same strain.
What are the treatments of the flu?
anti-fever medications-aspirin but not for young ones
antibiotics (may be prescribed for secondary bacterial infections; not encouraged.)
How do you prevent influenza?
1. Trivalent Inactivated Vaccine (TIV)
only certain vaccines are certified for young children
vaccine protects thru activation of IgG antibodies to specific strain's antigens
2. Live, attenuated influenza virus vaccine licensed as FluMist.
What are the 3 different influenza vaccines approved by the FDA?
egg-based flu vaccine (used to make both inactivated vaccine and live attenuated vaccine)
cell-based flu vaccine (mix vaccine viruses with cultured mammalian cells and let them replicate; fluid inside cell is collected and the virus antigen is purified)
recombinant flu vaccine ( isolate a certain protein from a naturally occurring wild type recommended vaccine virus combined w/portions of another virus that grows well in insect cells)
What is the Egg-Based Flu Vaccine?
Egg-based vaccine manufacturing is used to make both inactivated (killed) vaccine (usually called the “flu shot”) and live attenuated (weakened) vaccine (usually called the “nasal spray”).
What is the Cell-Based Flu Vaccine?
Manufacturers mix the vaccine viruses with cultured mammalian cells (instead of incubating them in eggs) and leave them to replicate for a few days. Then the virus-containing fluid is collected from the cells and the virus antigen is purified
What is the Recombinant Flu Vaccines?
manufacturers isolate a certain protein from a naturally occurring ("wild type") recommended vaccine virus (the HA protein, which induces an immune response in people).
These proteins are then combined with portions of another virus that grows well in insect cells.
this “recombinant” vaccine virus is then mixed with insect cells and allowed to replicate. The flu HA protein is then harvested from these cells and purified. The purified protein is packaged while waiting for FDA testing and approval to release lots. Recombinant flu vaccine is the only 100% egg-free vaccine on the U.S. market.
How is FluMist created?
prepared 4rm an egg-grown virus
-good for upper respiratory tract w/ cooler air being breathed in.
approved for healthy, non-pregnant people of 2-49 yrs old
What are the potential disasters viruses?
H1N1 Avian influenza
-virus can survive for >1 month in bird droppings during colder seasons and up to a wk in warm weather.
-those infected get high fever and pneumonia very quickly
---acquire genes 4rm other viruses;infection of other animal species && mutates rapidly.