LECTURE March, 29 , 2011 INFLUENZA Chinese physicians took live smallpox, scratch skin, and give it to people Then Jenner recognized can vaccinate with something not as virulent as the actual infection o Smallpox had high fatality rate o Survivors would be scarred o Milkmaids had perfect skin, they were exposed to cowpox that didnt cause disease in humans o Gave cowpox to a young boy, and then gave him smallpox o WHO campaigned to eliminate smallpox o 1979 smallpox eliminated Polio next campaign o Endemic in Nigeria o Rumours that it was a US plot to sterilize Muslim men or to give AIDS o So people refused it o So cases doubled and tripled polio started to spread again o Now cooperation and back on track to eliminate polio HPV vaccine o Zur Hausen people with cervical cancer had a virus, the HPV o Vaccine to two serotypes accounts for 70% of human cancer o Now widely used No vaccine to HIV, malaria parasite, influenza because they are pathogens with high mutation rates and high variability o Vaccine cannot account for the evolution of these pathogens and parasite Influenza is todays focus NOT stomach flu, but a respiratory illness Influenza spread Guinea pigs one infected at one end of chamber, uninfected at other end o In winter-like conditions, droplets in sneezing spread further than in summer-like conditions Three kinds of viruses C not included in any of the vaccines Orthomyoviruses o Many forms pleomorphic STRAINS o Negative-strand RNA virus = influenza Complimentary copy of virus in genome Each gene on different segment Can mix and match different segments to create new variant of virus Two major surface proteins, H and N Non-structural part of virus infectious power, but not part of structure o H attaches to sialic acids, endocytosis o Inside endosome, pH is acidic, causing conformational change in protein to expose fusion peptide, to lyse endosome and release viral RNA into cell www.notesolution.com
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