Staffan P.E. Sylvan is a senior expert in infectious diseases and communicable disease control and prevention. He has been the county medical officer for Uppsala County, Sweden. As such he was the director of the local department of communicable disease control and prevention and was very active in undertaking campaigns concerning the containment of the spread of communicable diseases such as pandemic influenza, Chlamydia, HIV and hepatitis A, B and C. He has a long standing research career particularly in the area of hepatitis immunology. He has published more than 65 papers in reputed journals
The aim of this study was to compare the impact of the pandemic influenza strain A(H1N1)pdm09 on the need for hospital care, intensive care and mortality in three countries in the southern hemisphere where no vaccination was implemented with the results obtained in Uppsala county, Sweden where vaccination with the pandemic vaccine Pandemrix was started two weeks before the begining of the outbreak. In Sweden pandemic influenza A(H1N1)pdm09 was notifiable from the microbiology departments. Notification from the clinicians was required for patients treated in the hospitals. Data on mortality was extracted from the patients electronic journal systems. The data from the three southern hemisphere countries was obtained from a data analysis made by the Swedish Institute for communicable disease control and prevention and was distributed on August 17th 2009 to all hospitals and county medical officers in Sweden. The 2009 A(H1N1) influenza pandemic resulted in a lower need for hospital care in two out of three countries from the southern hemisphere compared with Uppsala county. In contrast, the need for intensive care and the mortality rate in the three countries where no vaccination was performed was similar to those of Uppsala county, where 62% of the population had been vaccinated by January 2010. No clear benefit could be registered on the need for hospital care, intensive care and mortality of the massvaccination campaign implemented in Uppsala county. This is probably due to the late onset of the vaccination campaign. After the vaccination campaign 15 new cases of narcolepsy was diagnosed.
LI Can has completed her PhD and now a postdoctoral fellow in the Dept. of Microbiology, the University of Hong Kong. She mainly researches on vaccine and the pathogenesis of influenza viruses, including pandemic H1N1 virus, H5N1 and H7N9 viruses. She published several papers during her PhD study.
TLR ligands, which can directly stimulate immune responses towards antigens, have shown great promise as novel adjuvants in many vaccine studies. Imiquimod, a synthetic TLR7 agonist, could significantly enhance immune responses together with conventional vaccine strategies. Our previous study showed an inactivated 2009 pdm H1N1 vaccine combined with Imiquimod (VCI) could elicit immediate immune responses against influenza A (H1N1) pdm09 infection in BALB/c mice as early as 3 days prior to challenge. Survival rate was significantly improved in VCI group. Neutralizing antibody and virus-specific antibody could be detected in mouse sera at day 4 in VCI group. We further investigated the mechanisms by which imiquimod enhances the efficacy of vaccine. The results showed that intraperitoneal administration of VCI induced significant amount of monocytes recruitment to the peritoneal cavity; meanwhile peritoneal resident B cells are activated and migrated rapidly to lymphoid organs. We found that B cells in spleen increased and expressed increased surface marker CD86 after 18 hours treatment. B cells in lung also significantly increased rapidly after infection in VCI group compared with untreated mice. Germinal center involved B cells and plasma cells increased in lymph nodes at day 3 p.i.. These results indicated imiquimod combined with vaccine may stimulate local B cells activation and enhance the proliferation and differentiation. Finally, the fast-acting antibody-based immune responses induced by vaccine combined with imquimod may provide a new strategy facing immediate unpredicted influenza outbreaks. The mechanisms of early B cell activation deserve further study.