BACKGROUND: Strains of respiratory syncytial virus (RSV) can be classified by reactivity with monoclonal antibodies into two major subgroups A and B, then further into several antigenic variants in each subgroup. Antigenic characterization of strains prevailing in a particular community may be essential in the future development of vaccine. METHODS: We developed monoclonal antibodies (MAbs) to RSV subgroups A and B. Antigenic specificities were characterized by immunoblot assay and radioimmunoprecipitation. By the pattern of reactions with these MAbs, RSV isolated over 1990~1998 were categorized into subgroups A and B, then further into antigenic variants. RESULTS: Thirty-four monoclonal antibodies to RSV were produced; twelve were directed against nucleoprotein; seven against matrix protein; ten against fusion protein; and five against major envelope glycoprotein. During the study period, yearly epidemics of RSV infection existed. Both subgroups circulated concurrently in 6 epidemics with predominance of subgroup A, and only one of each subgroup was identified in 2. Antigenic variations were observed in matrix, fusion and major glycoprotein. Six antigenic variants were identified in subgroup A and 2 in subgroup B among 242 strains of RSV. One major variant of subgroup A dominated in all of the 7 subgroup A epidemics, while the dominant variant of subgroup B was different in each of the 7 subgroup B epidemics. CONCLUSION: During the study period, yearly epidemics of RSV infection existed. The proportion of each subgroup varied in each of the 8 epidemics. The antigenic variability of RSV should be considered in the future development of RSV vaccine.
Antibodies, Monoclonal* ; Antigenic Variation* ; Glycoproteins ; Nucleoproteins ; Respiratory Syncytial Viruses*

In order to develop a successful vaccine against deadly diseases with a wide range of antigenic diversity, an in-depth knowledge of the molecules and signaling mechanisms between the vaccine candidates and immune cells is required. Therefore, monitoring vaccine components, such as antigen or adjuvants, and immune cell dynamics at the vaccination site or draining lymph nodes can provide important information to understand more about the vaccine response. This review briefly introduces and describes various non-invasive molecular imaging methods for visualizing immune cell dynamics after vaccination.
Antigenic Variation ; Lymph Nodes ; Molecular Imaging ; Vaccination ; Vaccines

BACKGROUND: Influenza is a highly contagious respiratory disease. Influenza virus, which causes epidemics every winter season, has the high possibility of appearing with new virus types every year due to antigen variation. Therefore, we intended to analyze the data on the epidemiology of influenza that had been acquired by laboratory surveillance in Incheon during the 2003/2004 and 2004/ 2005 seasons and to apply the knowledge to the control and prevention of influenza in Korea. METHODS: Specimens were inoculated into Madin-Darby canine kidney (MDCK) cells and, when cytopathic effect (CPE) was seen, culture supernatants were tested by mutiplex RT-PCR for typing and subtyping of influenza viruses. RESULTS: The first virus of the season was isolated at week 47 (3rd week on November) in 2003 during 2003/2004 and at week 43 (4th week on October) in 2004 during 2004/2005, which was about 4 weeks earlier than in the 2003/2004 season. From 532 specimens cultured for influenza virus during the 2003/2004 season. 330 (62.0%) viruses were isolated: 161 (48.8%) A/H3N2, 1 (0.3%) A/H1N1, and 168 (50.9%) B. During 2004/2005 season, 457 specimens were tested and 278 (60.8 %) were positive for influenza virus: 232 (83.5%) A/H3N2, 5 (1.8%) A/H1N1, and 38 (13.7%) B. The incidence of influenza was the highest in the school-age children and young adults of 7 to 19 years age group in both seasons. CONCLUSION: Influenza virus was isolated at a high rate (more than 60%) by the laboratory influenza surveillance system in Incheon during the 2003/2004 and 2004/2005 seasons: the predominant strain was influenza A/H3N2 subtype.
Antigenic Variation ; Child ; Epidemiology ; Humans ; Incheon* ; Incidence ; Influenza, Human* ; Kidney ; Korea ; Orthomyxoviridae ; Seasons ; Young Adult

Noroviruses (NoV) are the major viral pathogen that causes epidemic acute gastroenteritis and outbreaks of food-borne illness. The major genotypes responsible for the epidemics of NoV are GII.4 and GII.3. However, most studies of NoV have been associated with GII.4 genotype and only few studies have been done with GII.3 genotype. Here, we selected 18 GII.3 strains, which recently circulated in Korea, and determined the partial sequences of the capsid gene. Phylogenetic analysis comparing these sequences with 29 reference strains from the GenBank database was performed using the MEGA program. All NoV GII.3 strains formed 2 distinct genetic lineages and variant groups. Lineage A showed 94.1~97.6%, 90.2~94.6% nucleotide identities from lineage B and variant group, respectively. Lineage B showed 90.2~94.6% nucleotide identities from variant group. These different genetic lineages based on the phylogenetic analysis of capsid sequences imply that the circulating Korean NoV GII.3 strains have potential antigenic variation.
Antigenic Variation ; Capsid ; Databases, Nucleic Acid ; Disease Outbreaks ; Gastroenteritis ; Genotype ; Korea ; Norovirus

Infection with influenza virus results in acquisition of immunity, preventing reinfection with the homologous virus. Although reinfection following primary infection is rare, its incidence depends on immunity of human body, antigenic diversity of influenza virus, and the presence of outbreak in the community. During the pandemic influenza (H1N1 2009), a child and two women were reinfected by H1N1 influenza virus several weeks after the primary infection, and they were successfully treated again by oseltamivir. This case series will provide additional information on diagnosis, treatment, and prevention of the pandemic influenza (H1N1 2009).
Antigenic Variation ; Child ; Female ; Human Body ; Humans ; Incidence ; Influenza, Human ; Orthomyxoviridae ; Oseltamivir ; Pandemics ; Viruses

Variant surface antigens (VSAs) encoded by pir families are considered to be the key proteins used by many Plasmodium spp. to escape the host immune system by antigenic variation. This attribute of VSAs is a critical issue in the development of a novel vaccine. In this regard, a population genetic study of vir genes from Plasmodium vivax was performed in the Republic of Korea (ROK). Eighty-five venous blood samples and 4 of the vir genes, namely vir 27, vir 21, vir 12, and vir 4, were selected for study. The number of segregating sites (S), number of haplotypes (H), haplotype diversity (Hd), DNA diversity (π and Θw), and Tajima’s D test value were conducted. Phylogenetic trees of each gene were constructed. The vir 21 (S=143, H=22, Hd=0.827) was the most genetically diverse gene, and the vir 4 (S=6, H=4, Hd=0.556) was the opposite one. Tajima’s D values for vir 27 (1.08530, P>0.1), vir 12 (2.89007, P<0.01), and vir 21 (0.40782, P>0.1) were positive, and that of vir 4 (−1.32162, P>0.1) was negative. All phylogenetic trees showed 2 clades with no particular branching according to the geographical differences and cluster. This study is the first survey on the vir genes in ROK, providing information on the genetic level. The sample sequences from vir 4 showed a clear difference to the Sal-1 reference gene sequence, whereas they were very similar to those from Indian isolates.
Antigenic Variation ; Antigens, Surface ; DNA ; Genetic Variation ; Haplotypes ; Humans ; Immune System ; Plasmodium vivax* ; Plasmodium* ; Republic of Korea* ; Trees ; United Nations

Echovirus 6 (ECV6) is the prevalent serotype detected in aseptic meningitis cases in Korea. To analyze the genetic variation of ECV6 isolates recently circulating in Korea, we determined the partial sequence of the VP1 capsid gene from 22 Korean ECV6 isolates and performed pairwise analysis against 42 reference strains from the GenBank database using MegAlign. The 22 Korean ECV6 isolates formed 3 distinct genetic clusters: Kor-lineage I, II, and III. The Korean ECV6 strains showed significant genetic diversity with 14.8~22.8% nucleotide divergence among the 3 different lineages. These ECV6 Kor-lineages were demonstrated to belong to different genetic clusters using VP1 sequence-based phylogenetic analysis, implying that the recently circulating Korean ECV6 strains have potential antigenic variation.
Antigenic Variation ; Capsid ; Databases, Nucleic Acid ; Echovirus 6, Human ; Enterovirus B, Human ; Genetic Variation ; Korea ; Meningitis, Aseptic

Despite recent innovative advances in molecular virology and the developments of vaccines, influenza virus remains a serious burden for human health. Vaccination has been considered a primary countermeasure for prevention of influenza infection. Live attenuated influenza vaccines (LAIVs) are particularly attracting attention as an effective strategy due to several advantages over inactivated vaccines. Cold-adaptation, as a classical means for attenuating viral virulence, has been successfully used for generating safe and effective donor strains of LAIVs against seasonal epidemics and occasional pandemics. Recently, the advent of reverse genetics technique expedited a variety of rational strategies to broaden the pool of LAIVs. Considering the breadth of antigenic diversity of influenza virus, the pool of LAIVs is likely to equip us with better options for controlling influenza pandemics. With a brief reflection on classical attenuating strategies used at the initial stage of development of LAIVs, especially on the principles underlying the development of cold-adapted LAIVs, we further discuss and outline other attenuation strategies especially with respect to the rationales for attenuation, and their practicality for mass production. Finally, we propose important considerations for a rational vaccine design, which will provide us with practical guidelines for improving the safety and effectiveness of LAIVs.
Antigenic Variation ; Cross Protection ; Humans ; Influenza Vaccines ; Influenza, Human ; Orthomyxoviridae ; Pandemics ; Reverse Genetics ; Seasons ; Tissue Donors ; Vaccination ; Vaccines, Inactivated

PURPOSE: To evaluated the effect of the intra-individual variation in the serum prostate specific antigen (PSA) level in men without prostate cancer to decide on the requirement of a prostate biopsy. MATERIALS AND METHODS: Patients, aged between 50 and 80 years, were screened for prostate cancer or lower urinary tract symptoms at least 2 times within 3 months using PSA or free PSA measurements. Patients with an initial PSA level between 2.0 and 10.0ng/ml were included. Those with prostate cancer, urinary tract infection or 5-alpha reductase inhibitor medication were excluded. The coefficient of variation (CV) was evaluated in each PSA range. RESULTS: The analysis included 139 patients, with a mean age 62.1 years. The level of free PSA was measured in 56 patients. The mean interval between the two PSA measurements was 36.6 days. The mean CVs for the total PSA and % free PSA were 21.5 and 22.2%, respectively. 20% of patients show a CV of more than 30%, implying a large variation. In our study, the 95% confidence interval of initial PSA levels between 3.0 and 4.9ng/ml included the PSA cut-off point (4.0ng/ml) in the visit results. CONCLUSIONS: The variation the PSA level was relatively small, but some patients showed a CV greater than 30%. Therefore, the intra-individual PSA variation should become part of interpreting the PSA test results, especially for men with a PSA value near the cut-off point.
Antigenic Variation ; Biopsy ; Humans ; Lower Urinary Tract Symptoms ; Male ; Oxidoreductases ; Prostate* ; Prostate-Specific Antigen* ; Prostatic Neoplasms* ; Urinary Tract Infections

In Sprague Dawley (SD) rats, antibodies against strains of Orinentia tsutsugamushi, Kato, Karp and Gilliam, were produced in order to investigate their longevity and cross-reactivities to their corresponding homologous and heterologous antigens. By immunofluorescence assay (IFA) of IgG and IgM, it was shown that the immunity to the homologous strains persisted at a higher level (longevity of at least 34 weeks with higher IFA titers). On the other hand, the immunity to the heterologous strains persisted at a lower level (longevity of 10 to 34 weeks with lower IFA titers). Since infection with one strain of O. tsutsugamushi does not preclude reinfection with other strains, understanding of the antigenic diversity of O. tsutsugamushi and duration of the immunity to both homologous and heterologous strain is very important in diagnosis of scrub typhus.
Animals ; Antibodies* ; Antigenic Variation ; Antigens, Heterophile ; Diagnosis ; Fluorescent Antibody Technique ; Hand ; Immunoglobulin G ; Immunoglobulin M ; Longevity* ; Orientia tsutsugamushi* ; Rats ; Rats, Sprague-Dawley* ; Scrub Typhus