Treyfish
Moderator
Date: Fri 29 May 2009
From: Motoi Suzuki
<motoi.suzuki@gmail.com>
Seasonal flu vaccine for 2008/2009 has no protective effect on novel
influenza A (H1N1) virus in Japan
-----------------------------------------------------------
As of Fri 29 May 2009, a total of 367 confirmed cases of human infection
with a novel influenza A (H1N1) virus had been reported to Japanese
Ministry of Health, Labour and Welfare (MHLW) [1]. Preliminary outbreak
investigation report from National Institute of Infectious Diseases, Tokyo,
Japan has provided important data on the effectiveness of pre-seasonal
vaccination on the new strain [2].
They investigated 43 RT-PCR confirmed cases reported from Kobe City. Their
median age was 17 years which ranged from 5 to 44 years. Among them, 42
reported the status of pre-seasonal vaccination for 2008/2009 season and
the coverage was 52.4 per cent. According to MHLW's estimation, the
coverage of influenza vaccine among Japanese population was 53.7 per cent
for those aged less than 13 years, 23.1 per cent for those aged 13 to 64
years, and 58.8 per cent for those aged over 64 years during the 2008/2009
season [3]. Taking account of the population age structure, 27.9 per cent
of Japanese people aged 5 to 44 years are estimated to have been vaccinated
for seasonal influenza virus. This indicates that vaccine coverage among
confirmed cases is no less than that of the population average.
It is too early to reach a conclusion about a possible negative effect, yet
it is already obvious that pre-seasonal vaccine for 2008/2009 season has no
protective effect on disease from the novel influenza A (H1N1) strain among
the Japanese population. This finding should be valuable information for
public health policy makers preparing for coming winter season.
References:
-----------
1. Infectious Disease Surveillance Center, National Institute of Infectious
Diseases, Tokyo, Japan. Novel Influenza A (H1N1), Laboratory confirmed
cases in Japan. <http://idsc.nih.go.jp/disease/swine_influenza_e/index.html>
2. National Institute of Infectious Diseases, Kobe Institute of Health.
Interim report on clinical presentation of the novel influenza A (H1N1)
cases reported from Kobe City.
<http://idsc.nih.go.jp/disease/swine_influenza_e/idsc_e2009/clinical_epi_kobe.html>
3. Japanese Ministry of Health, Labour and Welfare. Report on the estimated
demand for influenza vaccination for 2008/2009 season.
<http://www.mhlw.go.jp/shingi/2008/06/dl/s0618-9f.pdf> (available in
Japanese only)
--
Motoi Suzuki, MD, MSc
Public Health in Developing Countries candidate
London School of Hygiene and Tropical Medicine, London, UK
<motoi.suzuki@lshtm.ac.uk>
:tiphat:http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,77733
From: Motoi Suzuki
<motoi.suzuki@gmail.com>
Seasonal flu vaccine for 2008/2009 has no protective effect on novel
influenza A (H1N1) virus in Japan
-----------------------------------------------------------
As of Fri 29 May 2009, a total of 367 confirmed cases of human infection
with a novel influenza A (H1N1) virus had been reported to Japanese
Ministry of Health, Labour and Welfare (MHLW) [1]. Preliminary outbreak
investigation report from National Institute of Infectious Diseases, Tokyo,
Japan has provided important data on the effectiveness of pre-seasonal
vaccination on the new strain [2].
They investigated 43 RT-PCR confirmed cases reported from Kobe City. Their
median age was 17 years which ranged from 5 to 44 years. Among them, 42
reported the status of pre-seasonal vaccination for 2008/2009 season and
the coverage was 52.4 per cent. According to MHLW's estimation, the
coverage of influenza vaccine among Japanese population was 53.7 per cent
for those aged less than 13 years, 23.1 per cent for those aged 13 to 64
years, and 58.8 per cent for those aged over 64 years during the 2008/2009
season [3]. Taking account of the population age structure, 27.9 per cent
of Japanese people aged 5 to 44 years are estimated to have been vaccinated
for seasonal influenza virus. This indicates that vaccine coverage among
confirmed cases is no less than that of the population average.
It is too early to reach a conclusion about a possible negative effect, yet
it is already obvious that pre-seasonal vaccine for 2008/2009 season has no
protective effect on disease from the novel influenza A (H1N1) strain among
the Japanese population. This finding should be valuable information for
public health policy makers preparing for coming winter season.
References:
-----------
1. Infectious Disease Surveillance Center, National Institute of Infectious
Diseases, Tokyo, Japan. Novel Influenza A (H1N1), Laboratory confirmed
cases in Japan. <http://idsc.nih.go.jp/disease/swine_influenza_e/index.html>
2. National Institute of Infectious Diseases, Kobe Institute of Health.
Interim report on clinical presentation of the novel influenza A (H1N1)
cases reported from Kobe City.
<http://idsc.nih.go.jp/disease/swine_influenza_e/idsc_e2009/clinical_epi_kobe.html>
3. Japanese Ministry of Health, Labour and Welfare. Report on the estimated
demand for influenza vaccination for 2008/2009 season.
<http://www.mhlw.go.jp/shingi/2008/06/dl/s0618-9f.pdf> (available in
Japanese only)
--
Motoi Suzuki, MD, MSc
Public Health in Developing Countries candidate
London School of Hygiene and Tropical Medicine, London, UK
<motoi.suzuki@lshtm.ac.uk>
:tiphat:http://www.promedmail.org/pls/otn/f..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,77733