20. 16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-COVID19-Report-49.pdf
preprint
21. 16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
UKHSAとNHSのデータを⽤いたイングランドの情報
オミクロンはデルタと⽐較して
再感染のオッズ⽐︓5.41(95%CI: 4.87-6.00)
ワクチン未接種の場合: 6.36 接種済の場合: 5.02
preprint
45. https://www.research.ed.ac.uk/en/publications/severity-of-omicron-variant-of-concern-and-vaccine-effectiveness-
preprint
Table 3: Observed vs expected analysis for risk of hospital admission by S gene status
S Gene Status N
Person
Years
Hospital
Admissions
Expected
Admissions
Observed/
Expected LCL UCL
All cases
linking into
the EAVE
II dataset
S Positive 119100 4375.1 856 856.9 1 0.93 1.07
S Negative 22205 413.4 15 46.6 0.32 0.19 0.52
Weak S
Positive 2199 57.3 7 6.9 1.02 0.45 2
Other 990 33.8 * * 0.79 0.26 1.88
Unknown 1647 58.2 14 14.8 0.94 0.54 1.54
All cases S Positive 126464 4643.5 967 903.7 1.07 1 1.14
S Negative 23830 443.1 18 50.1 0.36 0.22 0.56
Weak S
Positive 2384 62.1 9 7.5 1.2 0.59 2.19
Other 1080 36.5 * * 0.71 0.24 1.69
Unknown 1813 63.3 17 16.1
1.05
0.64 1.65
All cases
followed up
for at least 7
days
S Positive 102765 4096.2 824 824.9 1 0.93 1.07
S Negative 4111 140.2 7 21.2 0.33 0.15 0.65
Weak S
Positive 995 37.5 7 5.3 1.32 0.59 2.59
Other 748 29.5 * * 0.64 0.18 1.7
Unknown 1336 52.8 10 14.1 0.71 0.36 1.25
All cases
aged 20-59
S Positive 68035 2489.4 575 575.6 1 0.92 1.08
S Negative 17302 322.9 15 34.4 0.44 0.25 0.7
SGTFありの22,205⼈(413.4⼈年︓観察期間)のうち
予測していた⼊院数は46.6例だったにも関わらず、
実際は15例の⼊院であった
→予測の0.32倍(95%CI 0.19-0.52)
46. https://www.research.ed.ac.uk/en/publications/severity-of-omicron-variant-of-concern-and-vaccine-effectiveness-
preprint
Table 3: Observed vs expected analysis for risk of hospital admission by S gene status
S Gene Status N
Person
Years
Hospital
Admissions
Expected
Admissions
Observed/
Expected LCL UCL
All cases
linking into
the EAVE
II dataset
S Positive 119100 4375.1 856 856.9 1 0.93 1.07
S Negative 22205 413.4 15 46.6 0.32 0.19 0.52
Weak S
Positive 2199 57.3 7 6.9 1.02 0.45 2
Other 990 33.8 * * 0.79 0.26 1.88
Unknown 1647 58.2 14 14.8 0.94 0.54 1.54
All cases S Positive 126464 4643.5 967 903.7 1.07 1 1.14
S Negative 23830 443.1 18 50.1 0.36 0.22 0.56
Weak S
Positive 2384 62.1 9 7.5 1.2 0.59 2.19
Other 1080 36.5 * * 0.71 0.24 1.69
Unknown 1813 63.3 17 16.1
1.05
0.64 1.65
All cases
followed up
for at least 7
days
S Positive 102765 4096.2 824 824.9 1 0.93 1.07
S Negative 4111 140.2 7 21.2 0.33 0.15 0.65
Weak S
Positive 995 37.5 7 5.3 1.32 0.59 2.59
Other 748 29.5 * * 0.64 0.18 1.7
Unknown 1336 52.8 10 14.1 0.71 0.36 1.25
All cases
aged 20-59
S Positive 68035 2489.4 575 575.6 1 0.92 1.08
S Negative 17302 322.9 15 34.4 0.44 0.25 0.7
・⼊院患者の多くは20-59歳
・60歳以上の⼊院患者は存在しなかった
47. https://www.research.ed.ac.uk/en/publications/severity-of-omicron-variant-of-concern-and-vaccine-effectiveness-
preprint
Table 3: Observed vs expected analysis for risk of hospital admission by S gene status
S Gene Status N
Person
Years
Hospital
Admissions
Expected
Admissions
Observed/
Expected LCL UCL
All cases
linking into
the EAVE
II dataset
S Positive 119100 4375.1 856 856.9 1 0.93 1.07
S Negative 22205 413.4 15 46.6 0.32 0.19 0.52
Weak S
Positive 2199 57.3 7 6.9 1.02 0.45 2
Other 990 33.8 * * 0.79 0.26 1.88
Unknown 1647 58.2 14 14.8 0.94 0.54 1.54
All cases S Positive 126464 4643.5 967 903.7 1.07 1 1.14
S Negative 23830 443.1 18 50.1 0.36 0.22 0.56
Weak S
Positive 2384 62.1 9 7.5 1.2 0.59 2.19
Other 1080 36.5 * * 0.71 0.24 1.69
Unknown 1813 63.3 17 16.1
1.05
0.64 1.65
All cases
followed up
for at least 7
days
S Positive 102765 4096.2 824 824.9 1 0.93 1.07
S Negative 4111 140.2 7 21.2 0.33 0.15 0.65
Weak S
Positive 995 37.5 7 5.3 1.32 0.59 2.59
Other 748 29.5 * * 0.64 0.18 1.7
Unknown 1336 52.8 10 14.1 0.71 0.36 1.25
All cases
aged 20-59
S Positive 68035 2489.4 575 575.6 1 0.92 1.08
S Negative 17302 322.9 15 34.4 0.44 0.25 0.7
この論⽂からわかったこと(私⾒あり)
・南アフリカの論⽂と同様に⼊院リスクは1/3程度
・ただしこちらの論⽂は⼊院患者数が少なくて正確に
評価できているのかは不明
48. https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-COVID19-Report-50.pdf
22 December 2021 Imperial College COVID-19 response team
Report 50: Hospitalisation risk for Omicron cases in England
Neil Ferguson1
, Azra Ghani, Wes Hinsley and Erik Volz on behalf of the Imperial College COVID-19 response
team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
49. https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-COVID19-Report-50.pdf
22 December 2021 Imperial College COVID-19 response team
Report 50: Hospitalisation risk for Omicron cases in England
Neil Ferguson1
, Azra Ghani, Wes Hinsley and Erik Volz on behalf of the Imperial College COVID-19 response
team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
UKHSAとNHSのデータを⽤いたイングランドの情報
SGTFなし(デルタ etc.)と⽐較して
SGTFあり(オミクロン疑い)は
1泊以上の⼊院のリスクが41%(95%CI: 37-45%)減少
(0泊の⼊院も含めると20-25%減少)
51. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
C or r e sp ondence
The new engl and jour nal of medicine
Effectiveness of BNT162b2 Vaccine against
Omicron Variant in South Africa
To the Editor: In early November 2021, the
B.1.1.529 (omicron) variant was first identified
in South Africa and has rapidly become the domi-
nant variant in Gauteng province, where a third
wave of coronavirus disease 2019 (Covid-19) driv-
en by the B.1.617.2 (delta) variant had largely
subsided. As of November 15, the omicron variant
was being detected in more than 75% of Covid-19–
positive tests that were sequenced in South Africa1
(Figs. S1 and S2 in the Supplementary Appendix,
available with the full text of this letter at
ated with the omicron variant during the period
from November 15 to December 7 in South Africa,
which we dubbed a proxy for dominance of the
omicron variant (omicron proxy period), against
estimates of vaccine effectiveness between Sep-
tember 1 and October 30, when the delta variant
was dominant (comparator period).
In our study, we used a test-negative design
and data-exclusion rules to obtain estimates of
vaccine effectiveness4
(Table S1), according to the
following formula: 1−odds ratio for Covid-19
52. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
<研究デザイン>
11⽉15⽇時点で南アフリカでは75%がオミクロン
→11⽉15⽇〜12⽉7⽇までの感染者を
オミクロンと仮定してワクチン効果を推定
(ワクチンはファイザー2回接種に限定して調査)
年齢・性別・重症化リスク因⼦・過去の感染歴
感染したタイミング(週)・居住地(州)
で交絡を調整した
53. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
results
er dur
the co
Dur
vaccin
interva
ported
measu
differe
when t
hospit
Thu
saw a
BNT16
agains
presum
ant as
of vaccine effectiveness should be viewed as conservative since unvaccinated controls m
cinated persons. On the basis of the number of Discovery Health patients who had been
2021, the rate of misclassification of unvaccinated controls was estimated to be no more
Table 2. Effectiveness of Two Doses of BNT162b2 Vaccine before and during
Proxy Omicron Period.*
Variable
Vaccine Effectiveness
(95% CI)
Comparator
Period
Proxy Omicron
Period
%
Overall estimate 93 (90–94) 70 (62–76)
Sensitivity analyses of PCR results
Patients with S-gene target failure — 69 (48–81)
Patients in Gauteng province — 70 (59–78)
Patients with Covid-19 symptoms — 50 (35–62)
* The overall estimates of vaccine effectiveness were calculated according to a
test-negative design after adjustment for confounders. The three sensitivity
analyses included the results of polymerase-chain-reaction (PCR) tests show-
54. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
results
er dur
the co
Dur
vaccin
interva
ported
measu
differe
when t
hospit
Thu
saw a
BNT16
agains
presum
ant as
of vaccine effectiveness should be viewed as conservative since unvaccinated controls m
cinated persons. On the basis of the number of Discovery Health patients who had been
2021, the rate of misclassification of unvaccinated controls was estimated to be no more
Table 2. Effectiveness of Two Doses of BNT162b2 Vaccine before and during
Proxy Omicron Period.*
Variable
Vaccine Effectiveness
(95% CI)
Comparator
Period
Proxy Omicron
Period
%
Overall estimate 93 (90–94) 70 (62–76)
Sensitivity analyses of PCR results
Patients with S-gene target failure — 69 (48–81)
Patients in Gauteng province — 70 (59–78)
Patients with Covid-19 symptoms — 50 (35–62)
* The overall estimates of vaccine effectiveness were calculated according to a
test-negative design after adjustment for confounders. The three sensitivity
analyses included the results of polymerase-chain-reaction (PCR) tests show-
オミクロン⾮流⾏期のVEは93%(95%CI: 90-94%)
オミクロン流⾏期のVEは70%(95%CI: 62-76%)
55. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
results
er dur
the co
Dur
vaccin
interva
ported
measu
differe
when t
hospit
Thu
saw a
BNT16
agains
presum
ant as
of vaccine effectiveness should be viewed as conservative since unvaccinated controls m
cinated persons. On the basis of the number of Discovery Health patients who had been
2021, the rate of misclassification of unvaccinated controls was estimated to be no more
Table 2. Effectiveness of Two Doses of BNT162b2 Vaccine before and during
Proxy Omicron Period.*
Variable
Vaccine Effectiveness
(95% CI)
Comparator
Period
Proxy Omicron
Period
%
Overall estimate 93 (90–94) 70 (62–76)
Sensitivity analyses of PCR results
Patients with S-gene target failure — 69 (48–81)
Patients in Gauteng province — 70 (59–78)
Patients with Covid-19 symptoms — 50 (35–62)
* The overall estimates of vaccine effectiveness were calculated according to a
test-negative design after adjustment for confounders. The three sensitivity
analyses included the results of polymerase-chain-reaction (PCR) tests show-
感度分析①︓SGTFありを計測した場合 VE69%
感度分析②︓流⾏地の患者のみを対象 VE70%
感度分析③︓症状のある⼊院患者を対象 VE50%
56. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
results
er dur
the co
Dur
vaccin
interva
ported
measu
differe
when t
hospit
Thu
saw a
BNT16
agains
presum
ant as
of vaccine effectiveness should be viewed as conservative since unvaccinated controls m
cinated persons. On the basis of the number of Discovery Health patients who had been
2021, the rate of misclassification of unvaccinated controls was estimated to be no more
Table 2. Effectiveness of Two Doses of BNT162b2 Vaccine before and during
Proxy Omicron Period.*
Variable
Vaccine Effectiveness
(95% CI)
Comparator
Period
Proxy Omicron
Period
%
Overall estimate 93 (90–94) 70 (62–76)
Sensitivity analyses of PCR results
Patients with S-gene target failure — 69 (48–81)
Patients in Gauteng province — 70 (59–78)
Patients with Covid-19 symptoms — 50 (35–62)
* The overall estimates of vaccine effectiveness were calculated according to a
test-negative design after adjustment for confounders. The three sensitivity
analyses included the results of polymerase-chain-reaction (PCR) tests show-
この論⽂の著者の意⾒としては…
・思ったより悪くないのでは︖
・ブースター接種でさらに良い結果が得られる可能性も
57. [Epub ahead of print, 2021 Dec 29]. N Engl J Med. 2021;10.1056/NEJMc2119270.
results
er dur
the co
Dur
vaccin
interva
ported
measu
differe
when t
hospit
Thu
saw a
BNT16
agains
presum
ant as
of vaccine effectiveness should be viewed as conservative since unvaccinated controls m
cinated persons. On the basis of the number of Discovery Health patients who had been
2021, the rate of misclassification of unvaccinated controls was estimated to be no more
Table 2. Effectiveness of Two Doses of BNT162b2 Vaccine before and during
Proxy Omicron Period.*
Variable
Vaccine Effectiveness
(95% CI)
Comparator
Period
Proxy Omicron
Period
%
Overall estimate 93 (90–94) 70 (62–76)
Sensitivity analyses of PCR results
Patients with S-gene target failure — 69 (48–81)
Patients in Gauteng province — 70 (59–78)
Patients with Covid-19 symptoms — 50 (35–62)
* The overall estimates of vaccine effectiveness were calculated according to a
test-negative design after adjustment for confounders. The three sensitivity
analyses included the results of polymerase-chain-reaction (PCR) tests show-
実際、この論⽂では接種からの⽇数を考慮されてないので
もしかするとVEはさらに過⼩評価されている可能性も…︖
58. 16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-COVID19-Report-49.pdf
preprint
59. 16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
再掲(再感染の項で取り上げ)ですがVEについても記載あり
ファイザー2回接種(平均140⽇経過)のVEは19%
ファイザーブースター接種14⽇経過後のVEは77%
preprint
65. C or r e sp ondence
The new engl and jour nal of medicine
Effectiveness of BNT162b2 Vaccine against
Omicron Variant in South Africa
To the Editor: In early November 2021, the
B.1.1.529 (omicron) variant was first identified
in South Africa and has rapidly become the domi-
nant variant in Gauteng province, where a third
wave of coronavirus disease 2019 (Covid-19) driv-
en by the B.1.617.2 (delta) variant had largely
subsided. As of November 15, the omicron variant
was being detected in more than 75% of Covid-19–
positive tests that were sequenced in South Africa1
(Figs. S1 and S2 in the Supplementary Appendix,
available with the full text of this letter at
NEJM.org). On November 26, the World Health
Organization declared omicron a variant of con-
cern. In a study of live-virus neutralization as-
says, omicron was shown to escape antibody
neutralization by the BNT162b2 messenger RNA
vaccine (Pfizer–BioNTech).2
Thus, data were
needed regarding the effectiveness of the current
vaccines against the omicron variant in prevent-
ing hospitalization for Covid-19.
Using data from Discovery Health, a South
African managed care organization, we estimated
the vaccine effectiveness of two doses of the
BNT162b2 vaccine (i.e., full vaccination) against
hospitalization for Covid-19 caused by the omi-
cron variant by analyzing data sets that included
the results of polymerase-chain-reaction (PCR)
assays, preauthorization admission data, a full
history of members’ medical records, registrations
regarding chronic diseases, and data regarding
body-mass index to obtain the number of Covid-19
risk factors per patient, according to the guide-
lines of the Centers for Disease Control and Pre-
vention (CDC).3
Vaccination status was deter-
ated with the omicron variant during the period
from November 15 to December 7 in South Africa,
which we dubbed a proxy for dominance of the
omicron variant (omicron proxy period), against
estimates of vaccine effectiveness between Sep-
tember 1 and October 30, when the delta variant
was dominant (comparator period).
In our study, we used a test-negative design
and data-exclusion rules to obtain estimates of
vaccine effectiveness4
(Table S1), according to the
following formula: 1−odds ratio for Covid-19
hospitalization in the vaccinated population, where
the odds ratio was calculated with the use of logis-
tic regression after adjustment for confounders
of age, sex, previous Covid-19 infection, surveil-
lance week, geographic location, and the number
of CDC risk factors. In this analysis, Covid-19
hospitalization was a dependent variable, and vac-
cination status was included as an independent
variable.
We then performed three sensitivity analyses
on different subsets of data during the omicron
proxy period. First, we performed PCR tests show-
ing S-gene target failure as an indication of omi-
cron infection. Second, we included only PCR re-
sults obtained from patients in Gauteng province,
given the geographic concentration of the omi-
cron variant during the study period. Third, we
limited PCR test results to those obtained from
patients who had been hospitalized (e.g., respi-
ratory medical admissions), with the latter used
as a proxy for identifying tests among a symp-
tomatic population (Table S4).
We analyzed 133,437 PCR test results that had
16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
+.
Updated 20-12-2021 to: (a) correct accidental transposition of S+ and S- columns in Table 3; (b) correct incorrect
total S+ and S- numbers given on page 5; (c) correct the labelling of the 18-20 age band in Table 1; (d) clarify that
VE analysis excluded reinfections; (e) provide separate estimates of the reinfection relative risk for vaccinated
and unvaccinated cases; (f) add a comment on page 5 that the crude ratios of hospitalisations to cases give no
information on severity on their own due to the differences in the age distribution of Omicron and Delta cases.
66. C or r e sp ondence
The new engl and jour nal of medicine
Effectiveness of BNT162b2 Vaccine against
Omicron Variant in South Africa
To the Editor: In early November 2021, the
B.1.1.529 (omicron) variant was first identified
in South Africa and has rapidly become the domi-
nant variant in Gauteng province, where a third
wave of coronavirus disease 2019 (Covid-19) driv-
en by the B.1.617.2 (delta) variant had largely
subsided. As of November 15, the omicron variant
was being detected in more than 75% of Covid-19–
positive tests that were sequenced in South Africa1
(Figs. S1 and S2 in the Supplementary Appendix,
available with the full text of this letter at
NEJM.org). On November 26, the World Health
Organization declared omicron a variant of con-
cern. In a study of live-virus neutralization as-
says, omicron was shown to escape antibody
neutralization by the BNT162b2 messenger RNA
vaccine (Pfizer–BioNTech).2
Thus, data were
needed regarding the effectiveness of the current
vaccines against the omicron variant in prevent-
ing hospitalization for Covid-19.
Using data from Discovery Health, a South
African managed care organization, we estimated
the vaccine effectiveness of two doses of the
BNT162b2 vaccine (i.e., full vaccination) against
hospitalization for Covid-19 caused by the omi-
cron variant by analyzing data sets that included
the results of polymerase-chain-reaction (PCR)
assays, preauthorization admission data, a full
history of members’ medical records, registrations
regarding chronic diseases, and data regarding
body-mass index to obtain the number of Covid-19
risk factors per patient, according to the guide-
lines of the Centers for Disease Control and Pre-
vention (CDC).3
Vaccination status was deter-
ated with the omicron variant during the period
from November 15 to December 7 in South Africa,
which we dubbed a proxy for dominance of the
omicron variant (omicron proxy period), against
estimates of vaccine effectiveness between Sep-
tember 1 and October 30, when the delta variant
was dominant (comparator period).
In our study, we used a test-negative design
and data-exclusion rules to obtain estimates of
vaccine effectiveness4
(Table S1), according to the
following formula: 1−odds ratio for Covid-19
hospitalization in the vaccinated population, where
the odds ratio was calculated with the use of logis-
tic regression after adjustment for confounders
of age, sex, previous Covid-19 infection, surveil-
lance week, geographic location, and the number
of CDC risk factors. In this analysis, Covid-19
hospitalization was a dependent variable, and vac-
cination status was included as an independent
variable.
We then performed three sensitivity analyses
on different subsets of data during the omicron
proxy period. First, we performed PCR tests show-
ing S-gene target failure as an indication of omi-
cron infection. Second, we included only PCR re-
sults obtained from patients in Gauteng province,
given the geographic concentration of the omi-
cron variant during the study period. Third, we
limited PCR test results to those obtained from
patients who had been hospitalized (e.g., respi-
ratory medical admissions), with the latter used
as a proxy for identifying tests among a symp-
tomatic population (Table S4).
We analyzed 133,437 PCR test results that had
16 December 2021 Imperial College COVID-19 response team
Report 49: Growth, population distribution and immune escape of
Omicron in England+
Neil Ferguson1
, Azra Ghani, Anne Cori, Alexandra Hogan, Wes Hinsley, Erik Volz on behalf of the
Imperial College COVID-19 response team
WHO Collaborating Centre for Infectious Disease Modelling
MRC Centre for Global Infectious Disease Analysis, Jameel Institute, Imperial College London
1
Correspondence: neil.ferguson@imperial.ac.uk
+.
Updated 20-12-2021 to: (a) correct accidental transposition of S+ and S- columns in Table 3; (b) correct incorrect
total S+ and S- numbers given on page 5; (c) correct the labelling of the 18-20 age band in Table 1; (d) clarify that
VE analysis excluded reinfections; (e) provide separate estimates of the reinfection relative risk for vaccinated
and unvaccinated cases; (f) add a comment on page 5 that the crude ratios of hospitalisations to cases give no
information on severity on their own due to the differences in the age distribution of Omicron and Delta cases.
これらのVEの違いは接種からの期間の違い︖
かもしれない(私⾒)
68. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
Letters
RESEARCH LETTER
Characteristics and Outcomes of Hospitalized
Patients in South Africa During the COVID-19
Omicron Wave Compared With Previous Waves
On November 24, 2021, a SARS-CoV-2 variant of concern,
Omicron (B.1.1.529), was identified in South Africa as respon-
sibleforafourthwaveofCOVID-19.1,2
Thehighnumberofspike
mutations has raised concerns about its ability to evade vac-
cine and spread.3,4
We assessed hospitalized patients with a
positive SARS-CoV-2 test result during the fourth wave com-
pared with previous waves.
Methods | Netcare is a private health care group consisting of
49 acute care hospitals (>10 000 beds) across South Africa.
Analysis wa
(SAS Institut
This stu
provided wr
Results | The
ing the same
4 vs maximu
tients presen
tive COVID-1
3 waves vs 41
ing wave 4 w
59 years in w
males.Signif
mitted in wa
69. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
Letters
RESEARCH LETTER
Characteristics and Outcomes of Hospitalized
Patients in South Africa During the COVID-19
Omicron Wave Compared With Previous Waves
On November 24, 2021, a SARS-CoV-2 variant of concern,
Omicron (B.1.1.529), was identified in South Africa as respon-
sibleforafourthwaveofCOVID-19.1,2
Thehighnumberofspike
mutations has raised concerns about its ability to evade vac-
cine and spread.3,4
We assessed hospitalized patients with a
positive SARS-CoV-2 test result during the fourth wave com-
pared with previous waves.
Methods | Netcare is a private health care group consisting of
49 acute care hospitals (>10 000 beds) across South Africa.
Analysis wa
(SAS Institut
This stu
provided wr
Results | The
ing the same
4 vs maximu
tients presen
tive COVID-1
3 waves vs 41
ing wave 4 w
59 years in w
males.Signif
mitted in wa
南アフリカからの報告︓
49の急性期病院(⺠間病院)のデータを公表
70. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
確かに重症化率・死亡率は低そうに⾒えるのだが…
(といっても2351⼈の患者のうち、約1%の
27⼈が死亡している)
71. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
懸念①
12⽉7⽇までの陽性症例のデータを⽤い
フォローアップ期間は12⽉20⽇まで
→ここから亡くなる⼈が増える可能性もある
72. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
懸念②
南アフリカの第4波(11⽉15⽇〜)の患者は
若者が多く基礎疾患も少ない⼈ばかり
→⾼齢者を含めたデータも検討する必要がある
73. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
懸念③︓このまま患者数が20倍になったら︖
74. [Epub ahead of print, 2021 Dec 30]. JAMA. 2021;10.1001/jama.2021.24868.
酸素投与・挿管患者などは結局以前のサージ期と
同じくらいになってしまう可能性…