A team of Prof. Dong-Kwon RHEE (School of Pharmacy, SKKU) and Dr. Man-Ki SONG (International Vaccine Institute; IVI) developed a novel vaccine which can prevent influenza (flu) virus and pneumococcal infections. In this study, PhD student Seung Han SEON and Prof. Sukneung PYO (SKKU), Dr. Jung Ah CHOI and Eunji YANG (IVI) have been participated. The vaccine they developed is highly feasible as a novel vaccine for preventing or mitigating influenza virus as well as pneumococcal infections.



To prevent flu infection, it is highly recommended to have flu vaccine every year. Also for pneumococcal diseases prevention, 23 valent polysaccharide vaccine or 13 valent conjugate vaccine is recommended. However, live attenuated vaccine they developed can prevent these irrelevant two infections at the same time.



In the year 2009, a new variety of flu virus infection could lead to significant mortality, due to secondary bacterial infection such as pneumococci and Staphylococcus aureus after flu virus infection. Thus, it is essential to develop a vaccine which can prevent secondary bacterial infections after flu pandemic. However, current 13 valent conjugate vaccine could not prevent the pneumococcus infection effectively after flu infection (Metzger et al., 2015).



They developed an attenuated pneumococcus vaccine devoid of ‘pep27’ gene and immunized mice intranasally. Subsequently, the immunized mice were challenged with flu virus followed by pneumococcus infections. Immunized group showed significantly higher survival rate than the non-immunized group.



Through this study, they also discovered that mice immunized with the live attenuated pneumococcal vaccine showed no body weight decrease after flu virus infection. Since body weight decrease is a token of flu virus infection, this discovery is highly meaningful. Moreover, flu virus titer in the immunized mice lung was much lower than the non-immunized control. This finding can provide a mile stone on vaccine development since vaccine is considered to prevent only a specific pathogen.



They are now studying how this intranasal vaccine can provide protection from flu virus as well as pneumococcal infections. Also they are checking whether this vaccine can provide other pathogens infections.



This study is supported by Korea Science Foundation and published in advance as a brief report in Journal of Infectious Diseases (Impact Factor 6.273: infectious diseases category top 92.26%) on June 14.



Published article:

·         Seon SH1#, Choi JA2#, Yang E2, Pyo S1, Song MK2*, Rhee DK1*, Intranasal Immunization with an Attenuated Pep27 Mutant Provides Protection from Influenza Virus and Secondary Pneumococcal Infections. J Infect Dis 2017; In Press

Abstract:
https://academic.oup.com/jid/article-abstract/doi/10.1093/infdis/jix594/4627914
Article (free access):
https://academic.oup.com/jid/article/doi/10.1093/infdis/jix594/4627914?guestAccessKey=8a78f6ee-1a14-480a-92e9-5828b113a888


Reference:

·         Metzger DW, Furuya Y, Salmon SL, Roberts S, Sun K. Limited Efficacy of Antibacterial Vaccination Against Secondary Serotype 3 Pneumococcal Pneumonia Following Influenza Infection. J Infect Dis 2015; 212:445-52.