BMC Infectious Diseases
http://www.biomedcentral.com/bmcinfectdis/content
(Accessed 28 March 2015)

Research article
A national cross-sectional study for poliovirus seroprevalence in the Republic of Korea in 2012: implication for deficiency in immunity to polio among middle-aged people
Hye-Jin Kim13, Seoyeon Hwang1, Somin Lee1, Yunhyung Kwon24, Kwangsook Park2, Young Joon Park2, Geun-Ryang Bae2, Sang Won Lee1, Yong-Seok Jeong3 and Ji-Yeon Hyeon1*
Author Affiliations
BMC Infectious Diseases 2015, 15:164 doi:10.1186/s12879-015-0894-z
Hye-Jin Kim and Seoyeon Hwang contributed equally to this work.
Published: 28 March 2015
Abstract (provisional)
Background
A worldwide poliomyelitis eradication program was initiated in 1988; however, strains of wild poliovirus (WPV) are still endemic in some countries. Until WPV transmission is eradicated globally, importation and outbreaks of WPV are alarming possibilities. This study is the first report to document the polio immunity after 2004, when an inactivated polio vaccine (IPV) was introduced in the Republic of Korea.
Methods
A total of 745 serum samples from randomly selected patients ranging from 6 to 84 years of age were used for neutralization tests, performed in the World Health Organization polio national reference laboratory.
Results
Among the 745 tested sera, 439 (58.9%) were seropositive and 19 (2.6%) were seronegative to all PV serotypes. In all age groups, PV3 showed the lowest level of seroprevalence, at 509 cases (68.3%), compared to 616 (82.7%) for PV1 and 685 (91.9%) for PV2. In the 6–10-year age group, which included IPV-immunized children, the highest seropositive rate was observed and the difference in seroprevalence between PV3 and other serotypes was the lowest compared to the other age groups immunized with oral PV vaccines (OPV). In addition, the seronegative rates of all three PV types in children aged 6–10 in this study were found to be lower than those in OPV-immunized children reported in a previous study from the Republic of Korea. Meanwhile, middle-aged subjects (41–60 years) had the lowest seroprevalence and geometric mean titer.
Conclusions
This study indicates a deficiency in immunity to PV in middle-aged individuals, and low seroprevalence to PV3 in all age groups. In addition, due to the ongoing risk of importing PV, middle-aged people should consider PV vaccination before visiting a PV-endemic country. Our findings provide data to assist those involved in deciding future national polio vaccination strategies for the maintenance of a polio-free status in Korea.
Research article
The long-term immunogenicity of recombinant hepatitis B virus (HBV) vaccine: contribution of universal HBV vaccination in Italy
Nicola Coppola, Anna Corvino, Stefania De Pascalis, Giuseppe Signoriello, Eliana Di Fiore, Albert Nienhaus, Evangelista Sagnelli, Monica Lamberti BMC Infectious Diseases 2015, 15:149 (25 March 2015)
Abstract
Background
Universal hepatitis B virus (HBV) vaccination of newborn babies was introduced in Italy in 1991 and was extended to 12-years-old children for the first 12 years of application so as to cover in a dozen years the Italian population aged 0-24 years. The aim of this study was to identify factors associated with long-term immunogenicity against HBV 17 years after primary vaccination in students attending medical schools in Naples, Italy.
Methods
1,704 students attending the school of medicine, schools of the healthcare professions, or postgraduate medical schools of the Second University of Naples, Italy, from September 2012 to December 2013 were enrolled in this study. Of these, 588 had been vaccinated against HBV in infancy and 1,116 when 12 years old. Multivariate logistic regression analysis was used to identify factors associated with the level of long-term immunogenicity.
Results
All vaccinated subjects were HBsAg/anti-HBc negative: 270 (15.8%) had an anti-HBs titer between 1 and 9 IU/L, 987 (57.9%) between 10 and 400 IU/L, and 447 (26.3%) over 400 IU/L. When compared with the latter two subgroups, those with anti-HBs titers lower than 10 IU/L were younger (24 plus/minus 5.2 years vs. 26  plus/minus  4.9 years, p<0.000), more frequently students attending a healthcare school (59% vs. 47%, p<0.001), and more frequently had been vaccinated in infancy (50% vs. 31.5%, p<0.0001). Multivariate logistic regression identified age at vaccination as the only factor independently associated with an anti-HBs titer <10 IU/L (OR: 2.43; C.I. 95%: 1.57–3.76, p=0.001).
Conclusions
Universal HBV vaccination in Italy has been more effective in generating a prolonged protective response in subjects vaccinated at adolescence than in infancy. Students with a low anti-HBs titer should be considered for a booster dose because most will be exposed to the risk of acquiring HBV for decades.