Genotype C2 Research Articles

Molecular characterization of measles virus strains causing subactute sclerosing panencephalitis in France in 1977 and 2007

Measles virus strains from two subacute sclerosing panencephalitis (SSPE) cases diagnosed in 1977 (Laine strain) and in 2007 (Hoedts strain) were studied. Phylogenetic analysis based on C-terminal part of the nucleoprotein and the entire H gene showed that Hoedts strain, circulating in France presumably in the 1980s, belonged to genotype C2. However, Laine strain, suspected to have circulated between 1940s and 1960s, could not be assigned to any known measles virus genotypes. Sequences analysis of the Laine strain suggested that it originated from a measles virus that may have circulating at the same period as the Edmonston strain. The analysis of the whole genome of both SSPE strains revealed biased hypermutations in M, F, and H gene. Some of these mutations like the L165P found in the M protein sequence of the Laine strain, the amino acid position 94, where a mutation M94V was found in the F protein sequence of the Hoedts strain are known to play an important role in the glycoprotein interaction and to impair the ability of measles virus strain to produce cell-free infectious viral particles.This is the first study on molecular characterization of the entire coding region of measles virus isolated from SSPE cases in France.

Status of Global Virologic Surveillance for Rubella Viruses

The suspected measles case definition captures rubella cases. Therefore, measles surveillance will be improved in the course of the control and eventual elimination of rubella transmission. One aspect of rubella control, virologic surveillance, is reviewed here. A systematic nomenclature for rubella viruses (RVs) based on 13 genotypes has been established and is updated when warranted by increases in information about RVs. From 2005 through 2010, the genotypes of RVs most frequently reported were 1E, 1G, and 2B, and genotypes 1a, 1B, 1C, 1h, 1j, and 2C were less frequently reported. Virologic surveillance can support rubella control and elimination. Synopses of rubella virologic surveillance in various countries, regions, and globally are given, including characterization of viruses from imported cases in a country that has eliminated rubella and studies of endemic viruses circulating in countries without rubella control objectives. Current challenges are discussed.

Full-length genomic sequence of hepatitis B virus genotype C2 isolated from a native Brazilian patient

The hepatitis B virus (HBV) is among the leading causes of chronic hepatitis, cirrhosis and hepatocellular carcinoma. In Brazil, genotype A is the most frequent, followed by genotypes D and F. Genotypes B and C are found in Brazil exclusively among Asian patients and their descendants. The aim of this study was to sequence the entire HBV genome of a Caucasian patient infected with HBV/C2 and to infer the origin of the virus based on sequencing analysis. The sequence of this Brazilian isolate was grouped with four other sequences described in China. The sequence of this patient is the first complete genome of HBV/C2 reported in Brazil.

PHYSICAL PROPERTIES AND COLOR CHARACTERISTICS OF IRANIAN GENOTYPES OF CORNELIAN CHERRY

ABSTRACT Cornelian cherry (Cornus mas L.) is known as a medicinal plant. It can be used as a fresh or dried fruit. In this study, color characteristics and some physical properties of three Iranian genotypes of cornelian cherry were studied. Color characteristics, true density and static coefficient of friction of cherries were measured using the L*a*b*model, toluene displacement method and tilting table, respectively. Dimensions, equivalent diameter and sphericity were also measured. Lightness, redness and color density of three genotypes were in the range of 20.68 to 26.10, 16.88 to 24.72 and 17.90 to 26.01, respectively. The maximum amount of bulk and true density were obtained for the genotype C2 (861 and 1118 kg/m3) and the maximum amount of repose angle was obtained for the genotype C12 (75°). Genotype C13 had the maximum value of porosity, sphericity and static coefficient of friction on the steel surface (23.54, 86.17 and 1.22 %, respectively).PRACTICAL APPLICATIONSThe marketing of agricultural products such as cornelian cherry and their by‐product depends on the quality of primary products and the type of process operation at postharvest stage. The efficient process operation of cornelian cherry such as handling, cleaning and sizing depends on appropriate performance of the equipments used. The designing of suitable equipments needs knowledge about physical properties of cornelian cherry. In this study, the physical properties of cornelian cherry were measured. The results of present study could be used to (1) identify optimal configuration of cornelian cherry process equipments; (2) design and construct the cornelian cherry process equipment; and (3) sort and select cornelian cherry genotypes based on their quality.

Formalin-inactivated vaccine provokes cross-protective immunity in a mouse model of human enterovirus 71 infection

Human enterovirus 71 (HEV71) has emerged as a major cause of epidemics of hand, foot and mouth disease associated with severe neurological sequelae in the Asia-Pacific region. In this study, a passive protection mouse model was used to evaluate the protective efficacy of formalin-inactivated HEV71 vaccines derived from a Chinese C4 genotype strain. Pregnant mice were immunised using a prime/boost strategy and ≥50U of vaccine protected five-day-old pups from lethal challenge with a mouse-adapted (B3 genotype) strain of HEV71. Immunised mice developed a neutralising antibody response to both the immunising C4 strain and to the mouse-adapted strain. Mice born to immunised dams showed significantly less myositis and reduced viral loads in tissues.

Impact of Hepatitis B Virus (HBV) X Gene Mutations on Hepatocellular Carcinoma Development in Chronic HBV Infection

The hepatitis B virus (HBV) PreS mutations C1653T, T1753V, and A1762T/G1764A were reported as a strong risk factor of hepatocellular carcinoma (HCC) in a meta-analysis. HBV core promoter overlaps partially with HBx coding sequence, so the nucleotide 1762 and 1764 mutations induce HBV X protein (HBx) 130 and 131 substitutions. We sought to elucidate the impact of HBx mutations on HCC development. Chronically HBV-infected patients were enrolled in this study: 42 chronic hepatitis B (CHB) patients, 23 liver cirrhosis (LC) patients, and 31 HCC patients. Direct sequencing showed HBx131, HBx130, HBx5, HBx94, and HBx38 amino acid mutations were common in HCC patients. Of various mutations, HBx130+HBx131 (double) mutations and HBx5+HBx130+HBx131 (triple) mutations were significantly high in HCC patients. Double and triple mutations increased the risk for HCC by 3.75-fold (95% confidence interval [CI] = 1.101 to 12.768, P = 0.033) and 5.34-fold (95% CI = 1.65 to 17.309, P = 0.005), respectively, when HCC patients were compared to CHB patients. Functionally, there were significantly higher levels of NF-κB activity in cells with the HBx5 mutant and with the double mutants than that of wild-type cells and the triple-mutant cells. The triple mutation did not increase NF-κB activity. Other regulatory pathways seem to exist for NF-κB activation. In conclusion, a specific HBx mutation may contribute to HCC development by activating NF-κB activity. The HBx5 mutation in genotype C2 HBV appears to be a risk factor for the development of HCC and may be used to predict the clinical outcomes of patients with chronic HBV infection.

Clinically silent forms may partly explain the rarity of acute cases of autochthonous genotype 3c hepatitis E infection in France

This is thefirst case report ona clinically andbiologically asympomatic immunocompetent patient of European origin with acute EV infection involving genotype 3c strains. Secondly, only cases ike this could explain the discrepancy existing between the high ates of HEV (hepatitis E virus) immunoglobulin G (IgG) serorevalence and the rarity of symptomatic HEV infection reported n industrialized countries. Thirdly, testing for hepatitis E among eople in contact with acute HEV patients should possibly be ecommended in nationwide epidemiological surveys, to detect symptomatic cases even showing normal liver enzyme levels, specially if a common risk factor possibly responsible for contamnation is found to exist.

On the origin and diversity of Newcastle disease virus in Tanzania

Free-range rural chickens (FRCs) dominate the poultry industry in developing countries and chickens are exposed to multi-host infections, including Newcastle disease virus (NDV). The knowledge about the characteristics of NDV from FRCs is limited. This study investigated the persistence, spread and risks of NDV from FRCs. NDV isolates (n = 21) from unvaccinated FRCs in Tanzania were characterised by conventional intracerebral pathogenicity index (ICPI) and sequence analysis of a partial region of the deduced fusion protein encompassing the cleavage site. Results showed that five isolates were screened as lentogenic, nine as mesogenic and six as velogenic. Phylogenetic analysis of the 21 isolates compared to reference sequences revealed three, four, nine and five isolates in genotypes 1, 2, 3c and 4a, respectively. Genotype 3c also included published sequences of Tanzanian isolates obtained from exotic birds and chicken isolates from Uganda. The analysis showed that NDV were persistently present among chicken populations and possibly spread through live chicken markets or migration of wild birds. Differences in amino acid sequences detected around the cleavage site separated the isolates in six types. However, cleavage site pattern could not fully differentiate mesogenic isolates from velogenic isolates.

Molecular epidemiology of the 2005 enterovirus 71 outbreak in central Taiwan

Since 1998, Taiwan has experienced annual outbreaks of enterovirus 71 (EV71) nationwide. The area around Taichung City experienced a particularly large outbreak in 2005, after which EV71 disappeared for 2 y before re-emerging in 2008. Here we present the clinical, genotypic, and epidemiological baseline data for the 2005 Taichung outbreak. Throat swab, stool and cerebrospinal fluid samples were collected and stored in viral transport medium. Samples were tested by reverse-transcriptase polymerase chain reaction and viral culture. Epidemiological, laboratory, and clinical data were extracted from medical record reviews. A total of 27 virus isolates were selected for phylogenetic analysis. Confirmed phylogenetic results of the viruses were separated into 5 groups. The 5'-UTR regions served as a focus for investigating genetic relationships among the 27 EV71 isolates, all of which belonged to a distinct clade in the C4 genotype. Most of the strains belonged to 5 observed epidemic groups. In conclusion, the 2005 outbreak in central Taiwan was caused by divergent EV71 strains belonging to the C4 genotype.

Genotypic Diversity of Complement Component C4 Does Not Predict Kidney Transplant Outcome

Gene copy number of complement component C4, which varies among individuals, may determine the intrinsic strength of the classical complement pathway. Presuming a major role of complement as an effector in transplant rejection, we hypothesized that C4 genetic diversity may partially explain the variation in allograft outcomes. This retrospective study included 1969 deceased-donor kidney transplants randomly selected from the Collaborative Transplant Study DNA bank. We determined recipient and donor gene copy number of total C4, C4 isotypes (C4A and C4B), and C4 gene length variants (C4L and C4S) by quantitative real-time PCR analysis. Groups defined according to recipient C4 gene copy number (low, intermediate, and high) had similar 10-year allograft survival. Genotypic groups showed comparable rates of graft dysfunction, treatment for rejection, immunological graft loss, hospitalization for infection, malignant disease, and death. Similarly, separate analyses of C4A, C4B, C4L, and C4S; combined evaluation of donor and recipient C4 genotype; or analysis of recipients with higher risk for rejection did not reveal considerable outcome effects. In conclusion, we did not demonstrate that C4 gene copy number associates with transplant outcome, and we found no evidence that the resulting variation in the strength of classical complement activation influences susceptibility to rejection.

An Investigation of Epidemic Enterovirus 71 Infection in Taiwan, 2008

Enterovirus 71 (EV71) is causing life-threatening hand-foot-mouth disease in Asia. In Taiwan, EV71 epidemics with different predominant genotypes occurred in 1998 (C2), 2000-2001 (B4), and 2004-2005 (C4). This genotype replacement may have important implications for vaccine development and prediction of epidemics. A nationwide EV71 outbreak occurred again in 2008, which provided a unique opportunity to characterize clinical, virologic, and serologic features of this epidemic. We analyzed clinical and virologic data of 111 EV71 patients hospitalized in 2008 and prospectively conducted follow-ups of healthy children from June 2006 to December 2008. Among the 111 EV71 inpatients, 21 (19%) developed complications. Among the 21 complicated cases, 15 had central nervous system complication only, 2 had acute heart failure, and 4 had central nervous system and pulmonary complications. In the prospective study, 11 symptomatic infections and 4 asymptomatic infections were detected. Twenty-two EV71 isolates were genotyped, and 21 of them belong to genotype B5, which is phylogenetically close to B5 viruses circulating in Southeast Asia. Serologic tests show that children infected with B5 viruses have lower geometric mean titers of neutralizing antibody against genotype C4 than those against genotype B5 (P = 0.004, t test). The 2008 nationwide EV71 epidemic was caused by genotype B5 that was likely introduced to Taiwan from Southeast Asia. Clinical features of the 2008 epidemic were not different from those observed before in Taiwan. Potential antigenic variations between genotype C4 and B5 viruses could be detected and its long-term epidemiologic significance needs further investigation to clarify.

The association of hepatitis B virus genotype and the basal core promoter mutation in Qidong, China

To investigate the prevalence of hepatitis B virus (HBV) genotypes and the association with hepatocellular carcinoma (HCC) or basal core promoter (BCP) mutation in Qidong, China. The whole genome of HBV or X gene sequences were obtained from serum samples of HBV infected patients by using PCR and direct sequencing methods. Phylogenetic tree was constructed to determine the genotypes or subgenotypes of HBV. According to the phylogenetic tree constructed from full-length sequence of HBV, genotype C2 was predominant in Qidong area. It was prevalent in 44 out of the 48 cases (91.7%), whereas genotype B2 only existed in 4 cases (8.3%). No other genotypes or recombinant types were found in Qidong patients. The result of genotyping based on X gene sequence confirmed the above observation. In a total of 182 samples, 169 (92.9%) showed genotype C2 and 10 (5.5%) showed genotype B2. There were 3 (1.6%) patients showed a coinfection with C2 and B2. The infection rate of genotype C in Qidong was significantly higher than that in neighboring city Shanghai (chi(2) = 12.252, P less than 0.01). There was no significant difference of genotype distribution between HCC and chronic hepatitis groups (P is more than 0.05). The frequency of T1762/A1764 double mutation in genotype C2 (70.3%) was significantly higher than that in genotype B2 (30.8%, P less than 0.05). The other two types of point mutation which also occurred in BCP, i.e. T1766 and A1768, were only seen in genotype C2. (1) Genotype C2 is the predominant genotype in Qidong, China. (2) There is no association between genotype C and HCC in Qidong. (3) Genotype C has a higher prevalence of BCP mutation than genotype B.

Genotype X/C recombinant (putative genotype I) of hepatitis B virus is rare in Hanoi, Vietnam—genotypes B4 and C1 predominate

There are eight known genotypes of hepatitis B virus, A-H, and several subgenotypes, with rather well-defined geographic distributions. HBV genotypes were evaluated in 153 serum samples from Hanoi, Vietnam. Of the 87 samples that could be genotyped, genotype B was found in 67 (77%) and genotype C in 19 (22%). All genotype C strains were of subgenotype C1, and the majority of genotype B strains were B4, while a few were B2. The genotype X/C recombinant strain, identified previously in Swedish patients of indigenous Vietnamese origin, was found in one sample. This variant, proposed to be classified as genotype I, has been found recently also by others in Vietnam and Laos. The current study indicates that the genotype X/C recombinant may represent approximately 1% of the HBV strains circulating in Vietnam.

Sequence analysis of six enterovirus 71 strains with different virulences in humans

Enterovirus 71 (EV71) infection is the main cause of hand, foot and mouth disease (HFMD) and has been associated with severe neurological diseases resulting in high mortalities. In this study, six EV71 strains isolated from patients with different clinical symptoms were sequenced and analyzed in a mouse model of EV71 infection. In a phylogenetic tree, based on the complete VP1 gene sequence, all six strains grouped into the C4 genotype. The sequence analysis revealed that there are nucleotide changes clustered in the internal ribosome entry site (IRES) element of the 5′-nontranslated region (5′-NTR), as well as amino acid differences clustered in the non-structural proteins. Importantly, we identified a unique amino acid difference (Val 1994-Ile 1994) that distinguished the more virulent strains, Anhui1 (Ah1), Henan1 (Hn1) and Henan2 (Hn2) from the less virulent strains, Chongqing1 (Cq1), Chongqing2 (Cq2) and Chongqing3 (Cq3). This amino acid difference is located in the finger domain of the viral RNA-dependent RNA polymerase 3D (3D pol). Furthermore, two-day-old Balb/c mice were inoculated with the Ah1, Hn1, Hn2, Cq1, Cq2 and Cq3 isolates by the intracerebral or intraperitoneal routes. All of the mice inoculated with Ah1, Hn1 and Hn2 isolates developed hind-leg paralysis and subsequently died. Mice inoculated with the Cq1, Cq2 or Cq3 isolates survived throughout the 21-day observation period. These results show that clinical isolates of EV71 associated with disease of different severity in humans have characteristic sequence differences and cause different mortality rates when inoculated into mice. These data also provide a rational basis to investigate the molecular determinants of EV71 pathogenesis using a reverse genetic approach.

Development of Hepatitis C Virus Genotyping by Real-Time PCR Based on the NS5B Region

BackgroundHepatitis C virus (HCV) genotyping is the most significant predictor of the response to antiviral therapy. The aim of this study was to develop and evaluate a novel real-time PCR method for HCV genotyping based on the NS5B region.Methodology/Principal FindingsTwo triplex reaction sets were designed, one to detect genotypes 1a, 1b and 3a; and another to detect genotypes 2a, 2b, and 2c. This approach had an overall sensitivity of 97.0%, detecting 295 of the 304 tested samples. All samples genotyped by real-time PCR had the same type that was assigned using LiPA version 1 (Line in Probe Assay). Although LiPA v. 1 was not able to subtype 68 of the 295 samples (23.0%) and rendered different subtype results from those assigned by real-time PCR for 12/295 samples (4.0%), NS5B sequencing and real-time PCR results agreed in all 146 tested cases. Analytical sensitivity of the real-time PCR assay was determined by end-point dilution of the 5000 IU/ml member of the OptiQuant HCV RNA panel. The lower limit of detection was estimated to be 125 IU/ml for genotype 3a, 250 IU/ml for genotypes 1b and 2b, and 500 IU/ml for genotype 1a.Conclusions/SignificanceThe total time required for performing this assay was two hours, compared to four hours required for LiPA v. 1 after PCR-amplification. Furthermore, the estimated reaction cost was nine times lower than that of available commercial methods in Brazil. Thus, we have developed an efficient, feasible, and affordable method for HCV genotype identification.

Genetic polymorphism of alcohol-metabolizing enzyme and alcohol dependence in Polish men

Alcohol dependence poses a serious medical and sociological problem. It is influenced by multiple environmental and genetic factors, which may determine differences in alcohol metabolism. Genetic polymorphism of the enzymes involved in alcohol metabolism is highly ethnically and race dependent. The purpose of this study was to investigate the differences, if present, in the allele and genotype frequency of alcohol dehydrogenase 1B (ADH1B), ADH1C and the microsomal ethanol-oxidizing system (MEOS/CYP2E1) between alcohol-dependent individuals and controls and also to determine if these genotypes cause a difference in the age at which the patients become alcohol dependent. The allele and genotype frequencies of ADH1B, ADH1C, and CYP2E1 were determined in 204 alcohol dependent men and 172 healthy volunteers who do not drink alcohol (control group). Genotyping was performed by PCR-RFLP methods on white cell DNA. ADH1B*1 (99.3%) and ADH1C*1 (62.5%) alleles and ADH1B*1/*1 (N = 201) and ADH1C*1/*1 (N = 85) genotypes were statistically more frequent among alcohol-dependent subjects than among controls (99.3 and 62.5%, N = 201 and 85 vs 94.5 and 40.7%, N = 153 and 32, respectively). Differences in the CYP2E1 allele and genotype distribution between groups were not significant. The persons with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes became alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes (28.08, 25.67 years vs 36.0, 45.05, 34.45 years, respectively). In the Polish men examined, ADH1C*1 and ADH1B*1 alleles and ADH1C*1/*1 and ADH1B*1/*1 genotypes favor alcohol dependence. The ADH1B*2 allele may protect from alcohol dependence. However, subjects with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes become alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes.

Detection of non-polio enteroviruses in Hungary 2000–2008 and molecular epidemiology of enterovirus 71, coxsackievirus A16, and echovirus 30

Human enteroviruses are associated with various clinical syndromes from minor febrile illness to severe, potentially fatal conditions like aseptic meningitis, paralysis, myocarditis, and neonatal enteroviral sepsis. Between June 2000 and August 2008 echovirus (E) type 2, 4, 6, 7, 9, 11, 13, 25, 30, coxsackievirus (CV) -A16, -A19, -B5, and enterovirus 71 (EV71) were reported in Hungary. In this study, 29 previously enterovirus positive samples from 28 patients diagnosed with hand, foot and mouth disease, meningitis and encephalitis, were molecularly typed. The genetic relationships of identified serotypes CV-A16, EV71, and E30 were assessed by direct sequencing of genomic region encoding the capsid protein VP1. The sequences were compared to each other and sequences from other geographical regions possessed in Genbank. The phylogenetic analysis of CV-A16 revealed that the viruses were mostly of Far-Eastern or Asia-Pacific origin. Typing of EV71 showed that one virus from 2000 belonged to genotype C1 and five viruses observed in 2004 and 2005 were identified as genotype C4. The 11 echovirus 30 strains showed homology with those of neighbor European countries. The molecular examination of E30 revealed that three separate lineages circulated in 2000, 2001, and 2004-2006 in Hungary.

Formaldehyde-inactivated whole-virus vaccine protects a murine model of enterovirus 71 encephalomyelitis against disease.

Enterovirus 71 (EV71) causes childhood hand, foot, and mouth disease and neurological complications, and no vaccines or therapeutic drugs are currently available. Formaldehyde-inactivated whole-virus vaccines derived from EV71 clinical isolates and a mouse-adapted virus (MAV) were tested in a mouse model of EV71 encephalomyelitis. After only two immunizations, given to mice at 1 and 7 days of age, the MAV vaccine protected mice at 14 days of age from disease. Tissues from immunized mice were negative for virus by viral culture, reverse transcriptase PCR, immunohistochemistry analysis, and in situ hybridization. Cross-neutralizing EV71 antibodies to strains with genotypes B3, B4, and C1 to C5 generated in immunized adult mice were able to passively protect 14-day-old mice from disease.

Detection of hepatitis E virus of genotype 3 in a farm pig in Kinshasa (Democratic Republic of the Congo)

Autochthonous hepatitis E is an emerging disease in industrialized countries where a growing body of data indicates that pigs represent a reservoir for hepatitis E virus (HEV) of genotype 3 or 4. In Africa, only HEV genotypes 1 and 2 have been identified in hepatitis E outbreaks as well as in sporadic cases. We aimed to investigate whether commercial pigs in sub-Saharan Africa might represent an HEV reservoir using molecular assays. Faecal samples from 40 pigs of the Pietrain race housed in a farm in Kinshasa (Democratic Republic of the Congo) were tested using in-house real-time reverse transcription (RT)-PCR and sequencing assays. HEV RNA was detected in faeces of one (2.5%) pig, and the HEV sequence obtained from this pig was classified genotype 3c, and was genetically related to human HEV sequences from France (89–92% nucleotide similarity) and pig HEV sequences from The Netherlands (88–91% nucleotide similarity). Epidemiological investigations revealed that Kinshasa farm pigs tested in the present study are descendants of pigs imported from Belgium in 2002, suggesting that pig HEV genotype 3c recovered in our study may have been imported from Belgium to Democratic Republic of the Congo. Our findings, although needing to be confirmed in further studies, also suggest that pigs in sub-Saharan Africa may be an HEV reservoir.

Depletion of measles virus glycoprotein-specific antibodies from human sera reveals genotype-specific neutralizing antibodies

Measles virus (MV)-neutralizing antibodies in sera from vaccinated subjects are mainly directed against the haemagglutinin (H) protein. It has been shown previously that depletion of vaccination-induced H-specific antibodies by co-culture of sera with cells expressing the MV Edmonston strain H glycoprotein resulted in almost complete elimination of neutralizing activity. In the present study, MV H and/or fusion (F) protein-specific antibodies were depleted from sera of naturally immune subjects. Early convalescent samples were collected 1.5 years after a well-characterized measles outbreak in Luxembourg caused by a genotype C2 virus, whilst late convalescent samples were collected from healthy Dutch subjects born between 1960 and 1970. Depletion of both H- and F-specific antibodies completely eliminated virus-neutralizing (VN) activity against MV Edmonston. However, in the early convalescent samples, residual VN antibody against wild-type MV genotype C2 was detected. This demonstrated that, although the majority of MV-specific VN antibodies recognized epitopes conserved between different genotypes, genotype-specific VN epitopes were also induced. In sera depleted of H-specific antibodies only, VN activity against MV Edmonston was not completely eliminated, demonstrating the presence of F-specific VN antibodies. In conclusion, this study demonstrated that a fraction of VN antibodies induced by wild-type MV genotype C2 does not neutralize MV strain Edmonston. In addition, it was shown that, in sera from naturally immune donors, the majority of VN antibodies are specific for MV H protein, but up to 10 % of neutralizing antibodies are specific for MV F protein.