Pandemics for exam 3 mc

SIGNIFICANT CHALLENGES FOR AH1N1 VACCINE DEVELOPMENT: WILL VACCINES SOLVE THE PROBLEMS OF INFLUENZA AH1N1?

Monday, February 6, 2012

THE PANDEMIC: April 27, 2009The emergence of avian influenza A(H5N1) followed by the A(H1N1) influenza pandemic

has focused the attention of the public and health authorities alike on the potential for prevention using the appropriate vaccines


Influenza Life Cycle

Reference:Med. Micro. Murray et al Chapter 56Monday, February 6, 2012



CO-CIRCULATION WITH SEASONAL

FLU IN 2010


UPDATE: SOUTHEAST ASIA

Latest available statistic for The Philippines from WHO: 3207 cases with 6 deaths as of 30 July 2009

In southeast Asia, transmission of pandemic influenza virus A(H1N1) persists, but current activity levels are low

Vietnam: influenza activity has declined substantially since peaking during October and November 2009

Thailand: focal outbreaks of influenza were reported from a few provinces in northern and central parts of the country, however, overall ILI activity remains low


UPDATE: SOUTHEAST ASIA

Latest available statistic for The Philippines from WHO: 3207 cases with 6 deaths as of 30 July 2009

In southeast Asia, transmission of pandemic influenza virus A(H1N1) persists, but current activity levels are low

Vietnam: influenza activity has declined substantially since peaking during October and November 2009

Thailand: focal outbreaks of influenza were reported from a few provinces in northern and central parts of the country, however, overall ILI activity remains low


VACCINATION UPDATE


• “CDC recommends influenza vaccination as the first and most important step in protecting against flu

VACCINATION UPDATE



• CDC is now encouraging everyone to get vaccinated against 2009 H1N1, including people 65 years and older

VACCINATION UPDATE




• While less common than with seasonal flu, severe illnesses and deaths from 2009 H1N1 have occurred in every age group, including people 65 and older

VACCINATION UPDATE





• Vaccination of people with certain health conditions is especially important because they are more likely to get serious flu-related complications

VACCINATION UPDATE





• Vaccination of people with certain health conditions is especially important because they are more likely to get serious flu-related complications

• Health complications that increase the risk of being hospitalized from 2009 H1N1 include:

• Lung disease like asthma or chronic obstructive pulmonary disease (COPD); Diabetes; Heart disease; Neurological disease; Pregnancy

VACCINATION UPDATE




RECOMMENDATION:

VACCINATION


ISSUE: MOCK-UP

VACCINES

Mock-up vaccines contain an active ingredient for an influenza virus that has not circulated recently in human populations and thus mimics the novelty of a pandemic

virus

Such advance studies can greatly expedite regulatory approval


ISSUE: MOCK-UP

VACCINES


• Mock-up pandemic influenza vaccine:

ISSUE: MOCK-UP

VACCINES



• a vaccine that mimics the future pandemic influenza vaccine in terms of its composition and manufacturing method

ISSUE: MOCK-UP

VACCINES




• NOTE: virus strain causing the pandemic is not known

ISSUE: MOCK-UP

VACCINES





• mock-up vaccine contains another flu strain instead

ISSUE: MOCK-UP

VACCINES






• a strain that is not circulating in humans, and to which humans have not been exposed in the past

ISSUE: MOCK-UP

VACCINES






• a strain that is not circulating in humans, and to which humans have not been exposed in the past

• test vaccines in preparation for any flu pandemic that may occur in the future : predict how people will react to the vaccine when the strain causing a pandemic is included

ISSUE: MOCK-UP

VACCINES


http://www.naturalnews.com/flu_pandemic.html

http://www.naturalnews.com/flu_pandemic.html

ISSUE: MOCK-UP

VACCINES


• ISSUES:

ISSUE: MOCK-UP

VACCINES


• ISSUES:

• 1) The viral strain chosen for this mock-up is one that is not currently circulating in humans. Thus, they are choosing a viral strain to which humans have no acquired immune defense.

ISSUE: MOCK-UP

VACCINES


• ISSUES:


• 2) These mock-up vaccines are tested on humans in order to "predict how people will react."

ISSUE: MOCK-UP

VACCINES


• ISSUES:



• CONSEQUENCES:

ISSUE: MOCK-UP

VACCINES


• ISSUES:



• CONSEQUENCES:

• injecting people with viral fragments that have never been previously encountered by humans

ISSUE: MOCK-UP

VACCINES


• ISSUES:



• CONSEQUENCES:


• if mistakes are made in the processing of these vaccines, causing live viruses to be injected (instead of sufficiently weakened viruses), this could result in the spread of that new virus among the human population

ISSUE: MOCK-UP

VACCINES


http://www.naturalnews.com/human_population.html


• ISSUES:



• CONSEQUENCES:


• if mistakes are made in the processing of these vaccines, causing live viruses to be injected (instead of sufficiently weakened viruses), this could result in the spread of that new virus among the human population

• this process could be used as vector through which infectious disease is spread (depends on which virus is chosen for the mock-up vaccines)

ISSUE: MOCK-UP

VACCINES




http://www.naturalnews.com/disease.html

http://www.naturalnews.com/disease.html

POSSIBLE MECHANISMS FOR THE EMERGENCE OF PANDEMIC VIRUSES

• Human virus and bird virus reassort gene sequences in pig, resulting in banded virus in pig and normal human subject

• alteration of receptor specificity during replication of an avian virus in pigs may occur both before and after reassortment with a human virus



• Bird virus adapts to virulent state in pigs, resulting in diseased human subject

• an avian virus may become adapted in pigs to the extent that it would not require reassortment with a human virus for efficient replication in humans



• Bird virus and human virus reassort gene sequences in human, resulting in banded virus in normal human subject

• direct transmission and reassortment in humans

• eg. outbreak in Hong Kong in 1997



• Bird virus adapts to virulent state in diseased humans, resulting in diseased human subject

• adaption in humans

• outbreak in Hong Kong in 1997


! 1. Vaccines! ! a. Inactivated! ! ! 1.whole! ! ! 2.subunit! ! b. Live attenuated- nasal spray available 2003! ! c. Recombinant - cDNA derived-in preparation

! 2. Antiviral Drugs! ! a. Amantadine! ! b. Neuraminidase inhibitors -oseleotamivir! ! highly specific - based on crystal structure! ! block active site! ! c. Extremely important to use in conjunction!! ! with a rapid diagnostic kit.

PREVENTION AND C0NTROL


Health & Medicine

Pandemics for exam 3 mc