LIFESCI 3C03 Lecture 5: Respiratory Viruses
18 Feb 2019
School
Department
Course
Professor
Respiratory Viruses
Significance
WHO estimates that acute respiratory infections kill 3.9 million people each year - they are the leading killer of •
children under 5
existing vaccines are imperfect, underused and unattainable during outbreaks of emerging respiratory viruses •
*You can sneeze up to 20 feet far - your respiratory droplets can spread to someone within this distance
Influenza
the flu virus infects the cells that line the respiratory tract •
infected cells die and give way to immune and inflammatory cells •
Flu Symptoms and Treatment
symptoms typically appear 1-4 days after exposure •
they include fatigue, fever, chills, cough, sore throat, runny or congested nose, and head and body aches •
antiviral medications can ease symptoms and shorten the duration of flu-related illness, but they don't always •
work - some strains may be resistant and the virus constantly changes
Types of Influenza
Influenza A - we get infected by this the most •
Influenza B - we also get infected by this often •
Influenza C - generally mild •
Influenza D - doesn't affect people •
Flu Subtypes and Strains
Influenza A can be divided into different subtypes based on the presence of two viral antigens: •
hemagglutinin (H) ◦
neuraminidase (N) ◦
Influenza A subtypes can be further divided into strains •
Influenza B can also be broken down into strains •
the seasonal flu involves strains of H1N1, H3N2 and influenza B •
H1N1 and H3N2 are seasonal strains of influenza - researchers have to predict which strains will become •
prominent to make vaccines in advance
Seasonal Flu
causes up to 5 million cases of severe illness and up to 650,000 respiratory deaths each year according to WHO •
older adults are the most at-risk in developed countries, while children account for 99% of all flu deaths in •
developing countries
pregnant women and people with chronic conditions or immunodeficiencies are also vulnerable •
older individuals more at risk in developed countries because they may be in high-risk areas such as hospitals or •
long term care facilities
Flu Prevention
avoid close contact with sick people •
antiviral drugs can easy symptoms and accelerate recovery •
wash hands and surfaces often •
avoid touching your eyes, nose or mouth •
cough and sneeze into your arm or a tissue •
best way to prevent flu is GET VACCINATED!! •
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
*you can sneeze up to 20 feet far - your respiratory droplets can spread to someone within this distance. Influenza a - we get infected by this the most. Influenza b - we also get infected by this often. Influenza a can be divided into different subtypes based on the presence of two viral antigens: hemagglutinin (h) neuraminidase (n) Influenza a subtypes can be further divided into strains. Influenza b can also be broken down into strains the seasonal flu involves strains of h1n1, h3n2 and influenza b. H1n1 and h3n2 are seasonal strains of influenza - researchers have to predict which strains will become prominent to make vaccines in advance. 5 days later, the fda approved four new vaccines by october, mass vaccinations were underway but many feared that vaccine manufacturers had pressured who into hyping the severity of the outbreak.
