Transcript AAAS_Flu_Short

Engineering Effective Response to
Outbreaks of Influenza
AAAS National Meeting, San Jose, California
Richard C. Larson
Massachusetts Institute of Technology
Cambridge, Massachusetts 02139
February 13, 2015
Status: MERS
Flu H5N1
Flu H9N7
Each a Major Threat to the World
And now, Ebola
We Often Plan Based on Past
“Anchored Events”
• 1918 ‘Spanish’ Flu
And, about 60 months ago, we
found ourselves living with
Novel H1N1 “Swine Flu”
Supported by the
CDC, the Sloan Foundation & IBM
• “Decision-Oriented Analysis of Pandemic
Flu Preparedness & Response.”
• Our focus: Social distancing, hygienic
responses and other NPI’s,
Non- Pharmaceutical Interventions.
• Vaccine allocation.
• Educational outreach.
Our Team
• Dr. Stan Finkelstein, Co-PI, ESD and Harvard Medical School
faculty member.
• Richard C. Larson, PI, ESD.
• John M. Barry, Historian
• James McDevitt, Ph.D., Faculty, Harvard School of Public Health
• Karima Nigmatulina, OR Ph.D. Student
• Anna Teytelman, OR Ph.D. student
• Dr. Sahar Hashmi, MD and ESD Ph.D. student
• Shiva Prakash, Sloan Masters student
• Kallie Hedberg, MIT CEE Undergraduate student
• Julia A. Hopkins, MIT CEE Undergraduate student (now MIT
PhD student in environmental science)
SARS, 2003
NPI’s: We Learned from SARS
A simple law----
Flu Fundamentals:
R0=lp
l=frequency of daily contacts (“lambda”)
p=probability of transmitting infection,
given contact
•Let’s talk about
l
Let’s talk
about p
Let’s talk about
The probability
distribution whose
mean is R0
Karima Nigmatulina’s Ph.D. Thesis:
Modeling and Responding to Pandemic Influenza:
Importance of Population Distributional Attributes and
Non-Pharmaceutical Interventions
Vaccine distribution ---
Large
Vaccine Distribution in the US
• The CDC started shipping vaccines in early October 2009
Measure: Number of Weeks
Before Peak that Vaccines
are Shipped
First vaccines delivered with
respect to peak of infection
> 4 weeks after peak
between 2 and 4 weeks after peak
1 week after peak
at peak
1 week before peak
between 2 and 4 weeks before peak
> 4 weeks before peak
H1N1 Vaccine Administration
Comparison of US, GA, and ME Epidemic
Curves
First vaccine
shipped,
Week 40
12
10
% ILI
8
% ILI US
6
% ILI Georgia
4
% ILI Maine
2
0
30
32
34
36
38
40
42
44
Week Ending October 10
46
48
50
52
2
4
6
MMWR Week
# Of States Peaking…
Week 39 or
earlier
Week 40 or
earlier
Week 41 or
earlier
Week 42 or
earlier
Week 43 or earlier
Week 44 or
earlier
10
14
24
34
40
44
Paper published: Vaccine availability in the United States during the 2009 H1N1 outbreak.
American Journal of Disaster Medicine.
Typical Example: Indiana
Indiana
14
2500000
2% vaccinated by
peak, Week 42
12
2000000
8
1500000
First vaccine
shipped, Week 40
6
1000000
# Vaccines
% ILI
10
% ILI
# Vaccines Shipped
# Vaccines Administered
4
500000
2
0
0
30 32 34 36 38 40 42 44 46 48 50 52 2
MMWR Week
4
6
Week Ending October 10
• Administration of vaccine lags shipment
• Vaccine effectiveness lags administration
 Few are protected in time to affect epidemic
Vaccine Distribution
Model
 Goal: To estimate numbers of flu cases averted by
delivery of the vaccine according to reported data.
 Goal: To estimate the beneficial effects of
delivering the vaccine earlier than actual.
 Key metrics: Numbers of infections averted;
number of deaths averted.
Example: Oklahoma
Oklahoma
35000
30000
25000
Nonobservable
20000
Vaccines
as
administer
ed
15000
10000
5000
0
22-Jul
Actual
Curve
Observable
22-Aug
22-Sep
22-Oct
22-Nov 22-Dec
Example: Oklahoma
30000
25000
20000
Difference:
(.93%, 2.29%) of population
15000
10000
5000
0
24-Oct
31-Oct
7-Nov
14-Nov 21-Nov 28-Nov
5-Dec
12-Dec 19-Dec
Vaccine Model: Results
• Effect of single vaccine depends on
timing
• Vaccinating early avoids infection for more than
the vaccinated person
• Needs to be taken into account
Best Paper of the Year Award, Value in Health
Think of Fire Fighting
• Is it better to pour lots of water on a fire
already blazing and out of control? OR
• To focus the limited water on at-risk
structures that are not yet burning, and
save them entirely?
Finally, Two More Items:
Article designated for AMA PRA Category 1 Credit™. Physicians and other
health professionals earn credit by reading the article in the online issue of
DMPHP and taking a quiz online.
The CDC is now undertaking a trial implementation of requiring
this article and its approach for all CDC employees.
Discussion…
HealthMap tracks Ebola’s
footprints online
• ESD Ph.D. Student -- Maia Majumder
•
http://healthmap.org/site/diseasedaily/article/estimating-fatality-2014-westafrican-ebola-outbreak-91014