Current Topics Flashcards
3 prime examples of vaccination working well
Problems with vaccines
* protection not complete (can still become infected and develop clinical signs of disease)
* Adverse events associated– generally mild (swlling, fever, aches, pain); severe side effects (allergic reaction, vaccine associated feline sarcomas)
* Many vaccines require a level of “herd immunity” for them to be effective- difficult to explain to people with no scientific background
* Some vaccines are expensive (e.g. Hendra virus vaccines $100-200 per horse, twice per year)– veterinary vaccines not subsidized by the government
Why are anti-vaccination sentiments re-emerging? Common themes with anti-vaccination?
People have never seen the diseases, if vaccination level drops below 75%, high risk of becoming ill
* social media facilitating dissemination of information (misinformation)
* safety concerns- toxins/ poisons, causing Autism
* concerns for effectiveness
* conspiracy theories– “big pharma”
* moral objections- against animal testing
* natural “alternatives”- homeopathy
What were the consequences of the Wakefield study?
Dangers associated with anti-vaccination sentiments?
Example of a vaccine concern in poultry?
What is influenza? Who does type A infect? Type B/C?
* An acute respiratory illness resulting from infection
* different strains have different severities
What does HA do? NA?
* HA- attach
NA- release
Where do influena A viruses come from?
* water birds- common
* all the ones in black have infected humans and can sustain themselves human to human (PANDEMIC)
* the ones in red- infected humans and caused severe disease but cannot transmit human to human
Influenza pandemics
Cytokine storms can cause the major deaths in a young population
Influenza epidemics
Important aspects of influenza that allow it to persist in the human population?
* can’t proof read and genetic segments
* Antigenic shift (pandemic)- avian and human virus able to infect the same cell–> when they replicate– they can mix genome segments
* Antigenic drift (epidemic- seasonal variation)- acquistion of point mutations over time
Impact of 1918 Spanish Flu pandemic (H1N1)?
* many died from bacterial infections
Why are we currently concerned about a influenza pandemic #1?
Why are we currently concerned about a influenza pandemic number 2?
What happened in 2009 with influenza?
How would you slow a pandemic?
How do the antiviral drugs work?
* M2 channel blockers- stop virus from getting out and replicating
* NA inhibitors- block the process of the virus getting out of the cell
Problems associated with using antiviral drugs to treat influenza infections?
Seasonal influenza vaccines
Dead viruses- cannot get influenza but can get a reaction
Problems with pandemic vaccination
* WHO tries to reach a consensus for what vaccine should have
Role of the Global Influenza Surveillance and Response System (GISRS)
What happens when a sample is received by the WHO Collaborating Centers (CC)?
How are the samples analyzed when they are received at a WHO CC?
How does influenza replicate?
How is influenza sampled?
How is influenza detected?
Where do most African Ebola Outbreaks occur since 1976?
What is the incubation of Ebola? Where is it most infectious at peak symptoms/death? How long can it persist in semen?
* Incubation 4-10 days- onset abrupt
* 10- 21 are peak symptoms/death
* Clinical recovery 20- 30 days
* Potential sexual transmission up to 82 days post recovery = 112 days
Why is Ebola classified as a level 4 agent?
Basis of high CFR 50-90% and absence of therapeutics or vaccines
Steps in PC4 lab
