Barbara Camilloni is presently researcher at the Univesity of Perugia. She completed herrnPostgraduate School in Microbiology and Virology and Ph.D. in “Molecular pathogenesis, immunology and control of transmissible agents causing major illnesses associated with poverty (malaria, tuberculosis and AIDS). Her major research mainly focus on Virological monitoring of seasonal influenza and pandemic as part of coordinated Italian surveillance network (InfluNet). She also worked on Evaluation of the effectiveness of influenza vaccination in the elderly and Surveillance of acute flaccid paralysis (national / international program of polio eradication), Virological surveillance of rotavirus infections in children.
In influenza vaccine efficacy studies, virus identification is considered the ideal end point. This approach, especially if performed in large populations could be difficult to carry out and the results could depend on the level of influenza viruses’ circulation. This is why serological studies are often used as surrogate methods. Here we analyze the antibody response of 181 elderly volunteers (aged ≥65 years) to 2014-15 influenza vaccine to understand if serological data are able to predict the vaccine efficacy. We compared the response of those who have or have not had a serologically evidenced influenza infection after vaccination (the volunteers that had a seroconversion on comparing hemagglutination inhibiting (HI) titers found 1 and 6 months after vaccination were considered positive for serological evidence of recent infection). Before vaccination the infected group showed lower antibody levels than uninfected volunteers, after vaccination these differences increased. Dividing the infected volunteers according to the absence or the presence of influenza like illness (ILI) and to the severity of the ILI, we found that, 1 month after vaccination, 80-90% of volunteers with severe infections or with mild infections, respectively, were unprotected (HI<40). On the other hand, among the infected volunteers not showing ILI and the non-infected volunteers, more than half were found to be protected. Although the validity of using serologic confirmation of infection rather than virus identification to determine vaccine efficacy has been questioned, our results, though obtained analyzing a small population, confirm the validity of the serological approach.
Ya-Yzu Chang is a Public Health Officer of the Department of Division of Preparedness and Emerging Infectious Disease in Taiwan Centers for Disease Control. She is responsible for policy making of influenza prevention and control and has handled experiences on 2009 H1N1 pandemic influenza and H7N9 influenza in Taiwan.
The 2015-2016 influenza season, was a tough period for Taiwan, having 1932 confirmed severe and complicated influenza cases including 328 estimated deaths. Most severe cases (about 77%) were infected with influenza A (H1N1) pdm09 virus. The majority of severe complicated influenza cases and deaths were adult aged 50-64 years. The incidences among all age groups were highest compared to the same period in the last 3 years, especially in the 50-64 age group. The main attacked age group changed from 65 years above to 50-64 years, similar demographic pattern seen in 2009 H1N1 pandemic. The government-funded influenza vaccination program in 2015-2016, following the international consensus, mainly targeted the elders aged more than 65 years, children aged six months through elementary school students and people aged above 50 years with chronic medical conditions. As a result, most people aged 50-64 years have not received influenza vaccines. In addition, the coverage rate of people with chronic diseases was only about 9%. Due to these reasons, in 2016/17 season, we plan to increase the purchase of influenza vaccines and vaccination points, as well as the awareness of the public, to improve the vaccination coverage rates and subsequently lower influenza incidence among people with chronic diseases.