Text
Public Health Working Group: SARSCoV-2 Status Report
5/20/20
SARS-CoV-2
Status Report
May 20, 2020
1
2
An R0 > 1 means outbreaks are likely
(R0)
5.0 - 6.0 (in China before control measures)
2.0 - 2.5 (with social distancing control measures)
3
4
Infected
individuals
can spread
the virus up to
2.3 days
before they
have
symptoms
The R0 is
affected by
the amount
of social
contact in a
population
5
6
1
Public Health Working Group: SARSCoV-2 Status Report
5/20/20
Primary means of
transmission
Secondary means
of transmission
Possible means
of transmission
Respiratory droplets
fall on surfaces that
are later touched by a
susceptible individual
When R0 > 1, preventing one infection has an exponential impact.
Physical distancing remains an important strategy because people
spread the virus before they develop symptoms.
7
8
Preliminary data
suggest that 20% of
COVID-19 cases are
severe, but this
number may be lower
if mild cases are
undetected.
Case fatality rate (CFR) varies by country;
likely overestimated due to lack of testing
These ”mild”
cases include
individuals who
are extremely ill
with flu-like
symptoms
9
10
Preliminary US data from February and March:
Mortality rates varies by age and ethnicity, and
increase when hospital capacity is exceeded
11
20-30% of recognized cases aged 20-65 were hospitalized
12
2
Public Health Working Group: SARSCoV-2 Status Report
True proportion of severe/fatal cases will be
unclear until antibody surveys are completed
5/20/20
Level of risk relative to other diseases is not clear
Difficult to characterize because of uncertainty in R0 and CFR
“This study will give us a
clearer picture of the true
magnitude of the COVID-19
pandemic in the US by
telling us how many people
in different communities
have been infected without
knowing it,” said Anthony
S. Fauci, M.D., NIAID
director.
Pink box reflects estimates from
February.
Green box reflects current
estimates, with a lower CFR and
a higher R0.
“These crucial data will
help us measure the
impact of our public health
efforts now and guide our
COVID-19 response moving
forward.”
13
14
We can move into the
“new normal” when
the population has
herd immunity.
Vaccination will likely
be necessary to
produce this level of
immunity in the
population.
Recent research
suggests that COVID19 infection causes
antibody production,
but it is unclear if these
antibodies confer longterm immunity.
15
e.g., remdesivir, an antiviral drug originally made to fight Ebola
16
NYT article 5/18/20:
Key take-home points
Any physical
contact carries
the risk of
infection,
severe illness,
and death.
This will remain
true until a
vaccine or
treatment is
widely available.
17
State and
federal
governments
will make
recommendatio
ns about when
businesses can
reopen;
individual
businesses will
then make
decisions about
whether the risk
of reopening is
worth the
continuing risks
to their
employees, and
in our case,
students.
Current hot
spots for
infection are
locations with
residential
living (prisons,
nursing homes,
hospitals).
Decisions made
by large
organizations
will have widely
varying impacts
for different
portions of the
population.
Experts expect
a second wave
of infections to
hit the US in the
fall.
Older individuals,
individuals with
chronic
conditions, and
Black Americans
will be put at
especially high
risk by the
decision of large
organizations to
open.
18
3
5/20/20
SARS-CoV-2
Status Report
May 20, 2020
1
2
An R0 > 1 means outbreaks are likely
(R0)
5.0 - 6.0 (in China before control measures)
2.0 - 2.5 (with social distancing control measures)
3
4
Infected
individuals
can spread
the virus up to
2.3 days
before they
have
symptoms
The R0 is
affected by
the amount
of social
contact in a
population
5
6
1
Public Health Working Group: SARSCoV-2 Status Report
5/20/20
Primary means of
transmission
Secondary means
of transmission
Possible means
of transmission
Respiratory droplets
fall on surfaces that
are later touched by a
susceptible individual
When R0 > 1, preventing one infection has an exponential impact.
Physical distancing remains an important strategy because people
spread the virus before they develop symptoms.
7
8
Preliminary data
suggest that 20% of
COVID-19 cases are
severe, but this
number may be lower
if mild cases are
undetected.
Case fatality rate (CFR) varies by country;
likely overestimated due to lack of testing
These ”mild”
cases include
individuals who
are extremely ill
with flu-like
symptoms
9
10
Preliminary US data from February and March:
Mortality rates varies by age and ethnicity, and
increase when hospital capacity is exceeded
11
20-30% of recognized cases aged 20-65 were hospitalized
12
2
Public Health Working Group: SARSCoV-2 Status Report
True proportion of severe/fatal cases will be
unclear until antibody surveys are completed
5/20/20
Level of risk relative to other diseases is not clear
Difficult to characterize because of uncertainty in R0 and CFR
“This study will give us a
clearer picture of the true
magnitude of the COVID-19
pandemic in the US by
telling us how many people
in different communities
have been infected without
knowing it,” said Anthony
S. Fauci, M.D., NIAID
director.
Pink box reflects estimates from
February.
Green box reflects current
estimates, with a lower CFR and
a higher R0.
“These crucial data will
help us measure the
impact of our public health
efforts now and guide our
COVID-19 response moving
forward.”
13
14
We can move into the
“new normal” when
the population has
herd immunity.
Vaccination will likely
be necessary to
produce this level of
immunity in the
population.
Recent research
suggests that COVID19 infection causes
antibody production,
but it is unclear if these
antibodies confer longterm immunity.
15
e.g., remdesivir, an antiviral drug originally made to fight Ebola
16
NYT article 5/18/20:
Key take-home points
Any physical
contact carries
the risk of
infection,
severe illness,
and death.
This will remain
true until a
vaccine or
treatment is
widely available.
17
State and
federal
governments
will make
recommendatio
ns about when
businesses can
reopen;
individual
businesses will
then make
decisions about
whether the risk
of reopening is
worth the
continuing risks
to their
employees, and
in our case,
students.
Current hot
spots for
infection are
locations with
residential
living (prisons,
nursing homes,
hospitals).
Decisions made
by large
organizations
will have widely
varying impacts
for different
portions of the
population.
Experts expect
a second wave
of infections to
hit the US in the
fall.
Older individuals,
individuals with
chronic
conditions, and
Black Americans
will be put at
especially high
risk by the
decision of large
organizations to
open.
18
3