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Nakamura K, Shirakura M, Suzuki Y, Naito T, Fujisaki S, Tashiro M, Nobusawa E. Development of a high-yield reassortant influenza vaccine virus derived from the A/Anhui/1/2013 (H7N9) strain. Vaccine 2015; 34:328-33. [PMID: 26657023 DOI: 10.1016/j.vaccine.2015.11.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 11/16/2015] [Accepted: 11/19/2015] [Indexed: 11/16/2022]
Abstract
In April 2013, the first three fatal cases of human infection with an avian influenza A virus (H7N9) were reported in China. Because of a pandemic threat by this virus, we have commenced to develop candidate vaccine viruses (CVVs). Three 6:2 genetic reassortant viruses with different hemagglutinin (HA) sequences, NIIDRG-10, -10.1 and -10.2, were generated by a reverse genetics technique between the high egg-growth master virus, A/Puerto Rico/8/34 (H1N1) and A/Anhui/1/2013 (H7N9), kindly provided by the Chinese Center for Disease Control and Prevention. The different HA gene sequences of the three CVVs were derived from the original virus stock. NIIDRG-10 possesses HA, whose sequence is identical to that of the original A/Anhui/1/2013 (H7N9) in the Global Initiative on Sharing Avian Influenza Data (EPI439507), while NIIDRG-10.1 and -10.2 possess amino acid differences, A125T and N123D/N149D, respectively, compared with NIIDRG-10. NIIDRG-10 replicated in embryonated chicken eggs with low hemagglutination titer 128, whereas NIIDRG-10.1 and -10.2 grew well with hemagglutination titer 1024. These viruses reacted well with a ferret antiserum raised against the original A/Anhui/1/2013 virus. Ferret antiserum against NIIDRG-10.1 reacted well with A/Anhui/1/2013 similar to the homologous virus NIIDRG-10.1. These results indicated that NIIDRG-10.1 passed the two-way test of antigenic identity. In contrast, the ferret antiserum against NIIDRG-10.2 reacted with A/Anhui/1/2013 at an 8-fold lower hemagglutination inhibition titer than with the homologous virus NIIDRG-10.2, indicating an antigenic change. The total and HA protein yields of NIIDRG-10.1 were 14.7 and 6.9 μg/ml, respectively, similar to those levels of high-yield seed viruses of seasonal influenza vaccines. NIIDRG-10.1 was approved as one of the CVVs for H7N9 viruses by the WHO in 2013. The candidate vaccine derived from NIIDRG-10.1 is currently being evaluated in a phase II clinical study in Japan.
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Affiliation(s)
- Kazuya Nakamura
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Masayuki Shirakura
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Yasushi Suzuki
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Tadasuke Naito
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Seiichiro Fujisaki
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Masato Tashiro
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan
| | - Eri Nobusawa
- Influenza Virus Research Center, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashi-murayama, Tokyo 208-0011, Japan.
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Abstract
The emergence of the H7N9 virus in China is another reminder of the threat of a global influenza pandemic. Many believe we could confront a pandemic by expanding our capacity to provide timely supplies of affordable pandemic vaccines and antiviral agents. Experience in 2009 demonstrated that this cannot and will not be done. Consequently, physicians may have little more to offer their patients than they had in the 1918 pandemic. Fortunately, several modern drugs (eg, statins, angiotensin II receptor blockers, angiotensin-converting enzyme inhibitors) can modify the host response to inflammatory illness, and laboratory and clinical studies suggest they might be used to treat pandemic patients. Unfortunately, little attention has been given to the research needed to support their use in patient care. There is no guarantee these drugs will work, but physicians will never know unless those responsible for pandemic preparedness recognize and act on the extraordinary possibility that they might save lives.
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