Post-vaccination Surveillance Research Articles

Evaluating the Effectiveness of Strategies for the Control of Equine Influenza Virus in the New Zealand Equine Population.

New Zealand has never experienced an equine influenza (EI) outbreak. The 2007 outbreak of EI in Australia showed that in a naïve population EI spreads rapidly and substantial efforts (in terms of movement restrictions, mass vaccination and post-vaccination surveillance) were required to achieve eradication. To control EI, it is essential that animal health authorities have well-defined strategies for containment, control and eradication in place before an incursion occurs. A spatially explicit stochastic simulation model, InterSpread Plus, was used to evaluate EI control strategies for the New Zealand situation. The control strategies considered were movement restrictions alone and movement restrictions in combination with one of three vaccination strategies beginning on day 14; suppressive, protective or targeted. The suppressive strategy involved vaccination in a 3 km radius around infected properties, while the protective strategy involved vaccination in a 7-10 km ring around infected properties. Targeted vaccination involved the vaccination of all breeding and racing properties within 20 km of an infected property. Simulations were carried out to determine the impact of timing of vaccination and earlier detection on the size of and duration of the outbreak. All three vaccination strategies implemented on day 14 resulted in between 1028 and 2161 fewer infected properties (P < 0.001), and an epidemic that was between 42 and 90 days shorter (P < 0.001) compared with movement restrictions alone. Any vaccination strategy implemented on day 7 resulted in fewer infected properties, compared with vaccination implemented on days 14 or 21. Overall, the suppressive vaccination strategy resulted in fewer infected properties. Our findings indicate that any vaccination strategy, if combined with complete movement restrictions could be effective for the control of EI, if an outbreak was to occur in New Zealand. If an outbreak were to occur, a simulation model has now been created to assist in decision-making using data from the actual outbreak.

Enteric viral infection in human and animal.

Enteric viral infection in human and animal.

Prevalence of Human Papillomavirus Types in Invasive Cervical Cancers From 7 US Cancer Registries Before Vaccine Introduction

We conducted a baseline study of human papillomavirus (HPV) type prevalence in invasive cervical cancers (ICCs) using data from 7 cancer registries (CRs) in the United States. Cases were diagnosed between 1994 and 2005 before the implementation of the HPV vaccines. Cancer registries from Florida, Kentucky, Louisiana, Michigan, Hawaii, Iowa, and Los Angeles, California identified eligible ICC cases and obtained sections from representative blocks of archived tumor specimens for DNA extraction. All extracts were assayed by linear array and, if inadequate or HPV negative, retested with INNO-LiPA Genotype test. Clinical and demographic factors were obtained from the CRs and merged with the HPV typing data to analyze factors associated with different types and with HPV negativity. A total of 777 ICCs were included in this analysis, with broad geographic, age, and race distribution. Overall, HPV was detected in 91% of cases, including 51% HPV-16, 16% HPV-18 (HPV-16-negative), and 24% other oncogenic and rare types. After HPV-16 and -18, the most common types were 45, 33, 31, 35, and 52. Older age and nonsquamous histology were associated with HPV-negative typing. This study provides baseline prevaccine HPV types for postvaccine ICC surveillance in the future. HPV-16 and/or -18 were found in 67% of ICCs, indicating the potential for vaccines to prevent a significant number of cervical cancers.

Determination of Pneumococcal Serotypes in Meningitis Cases in Niger, 2003–2011

BackgroundThe epidemiology of pneumococcal meningitis in the African ‘meningitis belt’ is poorly studied. In order to ensure an effective vaccination strategy and post-vaccination surveillance, we examined the serotype distribution patterns of pneumococcal meningitis in Niger over the period 2003–2011.MethodsCerebrospinal fluid (CSF) samples were collected from different health facilities throughout Niger in the frame of the national microbiological surveillance of meningitis. Determination of the serotype of CSF positive for pneumococci was performed using a sequential multiplex PCR method (SM-PCR) adapted with a national algorithm in which 32 different serotypes were covered and grouped into eight consecutive PCR.ResultsThe SM-PCR assay could predict the Sp serotype for 779 CSF (88.7%), 98 CSF (11.3%) were not-typeable in our national-adapted algorithm. In total, 26 different serotypes were identified. Serotype 1 (n = 393) was the most prevalent and accounted for 45.3% of infections, followed by serogroups/serotypes 12F/(12A)/(44)/(46) (7.3%), 6/(6A/6B/6C/6D) (5.4%), 14 (5.2%), 5 (4.6%), 23F (4.2%), 45 (3.6%), 2 (3.1%), 18/(18A/18B/18C/18F) (2.9%) and 17 others serotypes with a prevalence of less than 2%. The proportion of serotype 1 in infants(<2 years old) represented only 4.3% of the cases affected by this serotype. In contrast, serotypes 5, 6, 14, 19A and 23F were only detected in very young children.ConclusionsThe proportion of serotype 1 in the pneumococcal meningitis cases and the theoretical vaccine coverage across all age groups advocates for the introduction of a conjugate vaccine (PCV10 or 13) into the Expanded Programme on Immunization (EPI) in Niger. Post-vaccine introduction surveillance supported by molecular approaches will be essential to provide a comprehensive picture of the impact of the vaccine on the burden reduction of pneumococcal meningitis and on pneumococcal serotype distribution.

A cross-sectional study to estimate high-risk human papillomavirus prevalence and type distribution in Italian women aged 18–26 years

BackgroundPre-vaccination information on HPV type-specific prevalence in target populations is essential for designing and monitoring immunization strategies for cervical cancer (CC) prevention. Data on HPV prevalence in Italy are available for women over the age of 24 years, target of the population-based CC screening programmes; while data of HPV prevalence in younger ages are very limited. The present study enrolled Italian women aged 18–26 years in order to assess the prevalence and distribution of high-risk (HR) HPV types. Risk-factors correlated with HR-HPV positivity were also described.MethodsA sample of 2,289 women was randomly selected from the resident population lists of ten Local Health Units (LHUs) located in six Italian Regions scattered across the country; both rural and urban LHUs were involved. Women aged between 18 and 26 years and living in the selected LHUs were included in the study; pregnant women and women who did not speak Italian were excluded. A total of 1,102 women met the inclusion criteria and agreed to participate. Participants were offered pap test and Hybrid-Capture 2 (HC2) test for HR-HPV types and genotyping was performed on positive smears.ResultsOut of 1,094 valid samples, 205 (18.7%) were HR-HPV positive. Women with 2–4 (ORadj = 4.15, 95%CI: 2.56-6.72) and ≥5 lifetime partners (ORadj = 10.63, 95%CI: 6.16-18.36) and women who have used any contraceptive in the last six months (ORadj = 1.67, 95%CI: 1.09-2.54) had a higher risk to be infected; women living with their partner had a lower risk (ORadj = 0.56, 95%CI: 0.34-0.92) to acquire infection than women living with parents/friends/alone. Among HC2 positive women, HPV16 was the most prevalent type (30.9%), followed by 31 (19.6%), 66 (12.9%), 51 (11.3%), 18 (8.8%), 56 (8.8%). Co-infections of HR-HC2 targeted types were found in 20.4% of positive samples. The HR-HPV prevalence in women with abnormal cytology (52.4%) was significantly higher than in women with normal cytology (14.6%); however 33.0% of HR-HPV infected women had an abnormal cytology.ConclusionHR-HPV prevalence in Italian women aged 18–26 years was 19%, higher than what detected for older women, by other studies using the same molecular method and laboratory network; this result supports the choice of electing girls before the sexual debut as the primary target of HPV vaccination. The HPV type distribution found in this study may represent a baseline picture; an accurate post-vaccine surveillance is necessary to early detect a possible genotype replacement. The high prevalence of viral types other than vaccine-HPV types supports the necessity to guarantee the progression of CC screening programmes in vaccinated women.

Genetic characterisation of Malawian pneumococci prior to the roll-out of the PCV13 vaccine using a high-throughput whole genome sequencing approach.

BackgroundMalawi commenced the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant immunisation schedule in November 2011. Here we have tested the utility of high throughput whole genome sequencing to provide a high-resolution view of pre-vaccine pneumococcal epidemiology and population evolutionary trends to predict potential future change in population structure post introduction.MethodsOne hundred and twenty seven (127) archived pneumococcal isolates from randomly selected adults and children presenting to the Queen Elizabeth Central Hospital, Blantyre, Malawi underwent whole genome sequencing.ResultsThe pneumococcal population was dominated by serotype 1 (20.5% of invasive isolates) prior to vaccine introduction. PCV13 is likely to protect against 62.9% of all circulating invasive pneumococci (78.3% in under-5-year-olds). Several Pneumococcal Molecular Epidemiology Network (PMEN) clones are now in circulation in Malawi which were previously undetected but the pandemic multidrug resistant PMEN1 lineage was not identified. Genome analysis identified a number of novel sequence types and serotype switching.ConclusionsHigh throughput genome sequencing is now feasible and has the capacity to simultaneously elucidate serotype, sequence type and as well as detailed genetic information. It enables population level characterization, providing a detailed picture of population structure and genome evolution relevant to disease control. Post-vaccine introduction surveillance supported by genome sequencing is essential to providing a comprehensive picture of the impact of PCV13 on pneumococcal population structure and informing future public health interventions.

Vaccine-Type Human Papillomavirus and Evidence of Herd Protection After Vaccine Introduction

The aims of this study were to compare prevalence rates of human papillomavirus (HPV) in young women before and after HPV vaccine introduction to determine the following: (1) whether vaccine-type HPV infection decreased, (2) whether there was evidence of herd protection, and (3) whether there was evidence for type-replacement (increased prevalence of nonvaccine-type HPV). Young women 13 to 26 years of age who had had sexual contact were recruited from 2 primary care clinics in 2006-2007 for a prevaccination surveillance study (N = 368, none were vaccinated) and 2009-2010 for a postvaccination surveillance study (N = 409, 59% were vaccinated). Participants completed a questionnaire and were tested for cervicovaginal HPV DNA. HPV prevalence rates were compared in the pre- versus postsurveillance studies by using χ(2) tests. Propensity score weighting was used to balance differences in covariates between the 2 surveillance studies. The mean age was ∼19 years for both groups of participants and most were African American and non-Hispanic. After propensity score weighting, the prevalence rate for vaccine-type HPV decreased substantially (31.7%-13.4%, P < .0001). The decrease in vaccine-type HPV not only occurred among vaccinated (31.8%-9.9%, P < .0001) but also among unvaccinated (30.2%-15.4%, P < .0001) postsurveillance study participants. Nonvaccine-type HPV increased (60.7%-75.9%, P < .0001) for vaccinated postsurveillance study participants. Four years after licensing of the quadrivalent HPV vaccine, there was a substantial decrease in vaccine-type HPV prevalence and evidence of herd protection in this community. The increase in nonvaccine-type HPV in vaccinated participants should be interpreted with caution but warrants further study.

Serological methods used for rabies post vaccination surveys: An analysis

The assessment of fox immunity following oral rabies vaccination (ORV) is commonly applied to assess the efficacy of an ORV campaign in the field. Several ELISA kits have been developed and validated for their use for rabies serology in wildlife as an alternative to neutralizing techniques (NT), such as the fluorescent antibody virus neutralization test (FAVN) and the rapid fluorescent foci inhibition test (RFFIT). At a European level, NT and ELISA tests are used interchangeably and on different types of samples collected for vaccination follow-up. This has resulted in a difficulty in comparing the results generated with different diagnostic tools. We have evaluated (a) the effect of two different matrices commonly used for serology in red foxes on the results of the FAVN and (b) the performance of two commercially available ELISAs in comparison with the FAVN, as a gold standard, using a panel of over 700 field fox samples. Moderate agreement was observed when comparing results from different matrices. We found a very low level of agreement and low values of relative sensitivity and specificity of the ELISAs tested in comparison with the FAVN. Our findings confirm, using a vast collection of field samples obtained during post-vaccination surveillance campaigns in Italy, the need for improved reliability of certain serological tests.

Does HPV type 16 or 18 Prevalence in Cervical Intraepithelial Neoplasia Grade 3 Lesions Vary by Age? An Important Issue for Postvaccination Surveillance

We used existing data to investigate whether prevalence of HPV16/18 in cervical intraepithelial neoplasia 3 (CIN3) varies by age, in order to determine whether age specific baseline data is required as the prevaccination comparator for type-specific surveillance following HPV vaccination programs. We analyzed available Australian HPV typing data from 317 cervical smears from women with concurrent CIN3 on biopsy and conducted a review and analysis of the international literature. Among 317 women with CIN3, HPV16 was detected in 70% of those 16-25 years old, 59% of 26-35-year-olds and 48% of >36-year-olds (p = 0.025). This association took the form of a trend with decreasing HPV16 prevalence with increasing age (p = 0.007). That HPV16 is commoner in younger women with high-grade cervical lesions was consistent with all but one study of 18 identified in the literature. In screened populations, younger women with CIN3 are more likely to have HPV16 detected. To make valid pre- and post-vaccination comparisons, surveillance specimens for HPV typing should be both age stratified and lesion specific.

Evaluation of serological tests for H5N1 avian influenza on field samples from domestic poultry populations in Vietnam: Consequences for surveillance

In Vietnam, serological post H5N1 vaccination surveillance using the HI test is applied to assess the efficiency of the vaccination in addition to virological monitoring. In this paper we report on the evaluations of the performances of the haemagglutination inhibition (HI) test and of a H5-ELISA, using chicken and duck field samples. The evaluations were conducted by comparison with a pseudotyped-based virus neutralization test (H5pp VNT) performed in a reference laboratory and considered as a “gold standard” and also by using methods developed for imperfect reference test. Their global accuracy and best cut-offs were also estimated. Results from the HI test for several haemagglutinin subtypes and from a commercial type A influenza competition ELISA were also compared.The results showed that performance of the HI test was very good in comparison with the H5pp VNT. Data also clearly supported the cut-off of ≥4log2 used for the HI test for chickens but, a 3log2 positivity cut-off would be more appropriate for ducks. When compared with the VNT, the H5-ELISA showed poor specificity when using the positivity cut-off specified by the manufacturer but could be used as a screening test if confirmed by the HI test or the H5ppVNT which presents some interests for large scale testing (no need for biosafety level 3 conditions and high performance).A general and highly sensitive pre-screening can also be achieved using the detection of NP-specific antibodies with a competition ELISA. This appears of little interest in a context of high subtypes diversity where only a subtype is targeted for surveillance and control.

Serious adverse events following receipt of trivalent inactivated influenza vaccine in Korea, 2003–2010

BackgroundVaccination is very important for the control and prevention of influenza, yet no vaccine is perfectly safe. Little is known, however, about influenza vaccination-associated serious adverse events following immunization (AEFI). This study aimed to identify background information on influenza vaccination-related serious AEFI in Korea. MethodsRetrospective review of data from Korea National Vaccine Injury Compensation Program from 2003 to 2010. ResultsDistribution of approximately 75 million doses of influenza vaccine by end of 2010 gave rise to 42 potentially serious AEFI. In all, nine Guillain-Barré syndrome, eighteen other neurologic events, eight local events, and seven miscellaneous events were included. 62% of these events were identified to have unlike causal association with the vaccine. The reporting rate of serious AEFI ranged from 0.006 to 0.07 cases per 100,000 distributed doses of the vaccine. ConclusionGBS was the most common influenza vaccination-related serious AEFI. Enhancing post-vaccination GBS surveillance may increase public confidence in future routine and pandemic influenza vaccination.

Genetic structure of Streptococcus pneumoniae isolated from children in a tertiary care university hospital, in Korea, 1995 to 2005

We investigated the genetic structure of Streptococcus pneumoniae isolated from Korean children prior to the use of heptavalent pneumococcal conjugate vaccine (PCV7). A total of 278 pneumococcal isolates were obtained from invasive ( n = 77) and noninvasive ( n = 201) specimens from children <5 years of age that visited the Seoul National University Children's Hospital between 1995 and 2005; these samples were serotyped. Two hundred seventy-eight isolates were characterized by multilocus sequence typing, antibiotic susceptibility pattern testing with the E-test. The common serotypes were 19F (22.7%), 23F (19.1%), 19A (14.4%), 6B (11.2%), 6A (8.3%), 14 (5.4%), and 9V (4.3%); these 7 serotypes accounted for 85.3% of the 278 isolates. The isolates belonged to 23 serotypes and 81 sequence types (STs) (including 48 newly discovered STs). The eBURST analysis showed 7 clonal complexes (CCs). CC271 was the main CC of serogroup 19; CC81 and CC3115, serotype 6A; CC81 and CC880, serotype 23F; CC90, serotype 6B; CC166, serotype 9V; and CC554, serotype 14. Nonsusceptibility rates to penicillin and erythromycin among the invasive isolates were 9.1% and 94.8%, respectively. The resultant database may be useful for postvaccine surveillance.

Dynamic models of pneumococcal carriage and the impact of the Heptavalent Pneumococcal Conjugate Vaccine on invasive pneumococcal disease

BackgroundThe 7-valent pneumococcal conjugate vaccine has been introduced in national immunisation programmes of most industrialised countries and recently in two African GAVI eligible countries (Rwanda and The Gambia). However the long term effects of PCV are still unclear, as beneficial direct and herd immunity effects might be countered by serotype replacement.MethodA dynamic, age-structured, compartmental model of Streptococcus pneumoniae transmission was developed to predict the potential impact of PCV7 on the incidence of invasive disease accounting for both herd immunity and serotype replacement effects. The model was parameterised using epidemiological data from England and Wales and pre and post-vaccination surveillance data from the US.ResultsModel projections showed that serotype replacement plays a crucial role in determining the overall effect of a PCV7 vaccination programme and could reduce, negate or outweigh its beneficial impact. However, using the estimate of the competition parameter derived from the US post-vaccination experience, an infant vaccination programme would prevent 39,000 IPD cases in the 20 years after PCV7 introduction in the UK. Adding a catch-up campaign for under 2 or under 5 year olds would provide a further reduction of 1,200 or 3,300 IPD cases respectively, mostly in the first few years of the programme.ConclusionsThis analysis suggests that a PCV vaccination programme would eradicate vaccine serotypes from circulation. However, the increase in carriage of non-vaccine serotypes, and the consequent increase in invasive disease, could reduce, negate or outweigh the benefit. These results are sensitive to changes in the protective effect of the vaccine, and, most importantly, to the level of competition between vaccine and non-vaccine types. The techniques developed here can be used to assess the introduction of vaccination programmes in developing countries and provide the basis for cost-effectiveness analyses.

Prophylactic human papillomavirus vaccines: will they do their job?

The prophylactic HPV L1 virus like particle vaccines are highly efficacious preventing >98% of HPV 16/18 caused high grade cervical intra-epithelial neoplasia (CIN2/3) according to protocol group in phase III randomized clinical trials over approximately 4 years. Data from the trials together with postvaccine surveillance indicates that they have a good safety profile. As the current HPV vaccines include only two of the 15 oncogenic HPVs, they will not eliminate cervical cancer or the other HPV associated ano-genital diseases but could reduce, for example, the incidence of cervix cancer by up to 70-80%, if effectively delivered to adolescent females.

Post vaccination rotavirus surveillance in Hungary, in 2007

Vaccination is the main strategy to control severe dehydrating gastroenteritis caused by rotaviruses in early childhood. The availability of new generation rotavirus vaccines has led to an intensification of strain surveillance worldwide, in part, to gauge the impact of the possible vaccine-driven immune selection of wild-type rotavirus strains. In the present study, authors describe the strain prevalence data obtained in 2007, with the involvement of different regions of Hungary. Genomic RNA was extracted from rotavirus-positive stool samples collected mainly from children and then subjected to genotyping using multiplex RT-PCR assay. Type-specific primers targeted G1 to G4, G6, G8 to G10, and G12 VP7 specificities, and P[4], P[6], and P[8] to P[11] VP4 specificities were used. Out of 489 rotavirus-positive specimens, collected from 482 patients, 466 and 474 were successfully G and P typed, respectively, and both G and P type specificities could be assigned for 457 strains. Prevalence data showed the predominance of G4P[8] (31.5%) strains, followed by G1P[8] (28.3%), G2P[4] (19.3%), and G9P[8] (10.2%). Minority strains were G1P[4] (0.4%), G2P[8] (1.3%), G3P[9] (0.2%), G4P[6] (0.7%), G6P[9] (0.4%), G8P[8] (0.2%), G9P[4] (0.2%), G9P[6] (0.8%), and G12P[8] (0.4%). Mixed infections were found in 1.2% of the samples, while 4.9% remained partially or fully non-typified. Our data indicate that the antigen specificities of medically important rotavirus strains identified in this 1-year study are well represented in the vaccines available in the pharmaceutical private market in Hungary. Depending on the vaccination coverage achievable in the forthcoming years, the post-vaccination rotavirus strain surveillance may allow us to gain comprehensive information on the impact of rotavirus vaccines on the prevalence of circulating rotavirus strains.

Analysis of vaccine-virus-associated rabies cases in red foxes (Vulpes vulpes) after oral rabies vaccination campaigns in Germany and Austria

To eradicate rabies in foxes, almost 97 million oral rabies vaccine baits have been distributed in Germany and Austria since 1983 and 1986, respectively. Since 2007, no terrestrial cases have been reported in either country. The most widely used oral rabies vaccine viruses in these countries were SAD (Street Alabama Dufferin) strains, e.g. SAD B19 (53.2%) and SAD P5/88 (44.5%). In this paper, we describe six possible vaccine-virus-associated rabies cases in red foxes (Vulpes vulpes) detected during post-vaccination surveillance from 2001 to 2006, involving two different vaccines and different batches. Compared to prototypic vaccine strains, full-genome sequencing revealed between 1 and 5 single nucleotide alterations in the L gene in 5 of 6 SAD isolates, resulting in up to two amino acid substitutions. However, experimental infection of juvenile foxes showed that those mutations had no influence on pathogenicity. The cases described here, coming from geographically widely separated regions, do not represent a spatial cluster. More importantly, enhanced surveillance showed that the vaccine viruses involved did not become established in the red fox population. It seems that the number of reported vaccine virus-associated rabies cases is determined predominantly by the intensity of surveillance after the oral rabies vaccination campaign and not by the selection of strains.

Prevalence of Genital Human Papilloma Virus Infection and Genotypes among Young Women in Sicily, South Italy

Infection with oncogenic human papilloma virus (HPV) types is a necessary cause of cervical cancer. This study assessed the prevalence of HPV infection and genotypes among 1,006 randomly selected women, ages 18 to 24 years, living in Sicily (south Italy). The overall HPV rate was 24.1% (95% confidence interval, 21.5-26.9). The most frequent types were HPV-16 (4.5%), HPV-53 (2.7%), and HPV-84 (2.6%). The prevalence of vaccine types HPV-6, HPV-11, and HPV-18 was 1.4%, 0.1%, and 1.3%, respectively. Cytologic abnormalities were uncommon (3.1%) and associated with HPV detection (P < 0.0001). The only risk factor for HPV infection was the number of sexual partners (women with 2-3 partners versus women with 1 partner: odds ratio, 3.86; 95% confidence interval, 2.45-6.09). Genital HPV infection is relatively high in young Italian women. The high prevalence of viral types other than vaccine types should be taken into account to ensure accurate postvaccine surveillance and early detection of a possible genotype replacement.

Molecular epidemiology of pneumococci obtained from Gambian children aged 2–29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine

BackgroundThe study describes the molecular epidemiology of Streptococcus pneumoniae causing invasive disease in Gambian childrenMethodsOne hundred and thirty-two S. pneumoniae isolates were recovered from children aged 2–29 months during the course of a pneumococcal conjugate vaccine trial conducted in The Gambia of which 131 were characterized by serotyping, antibiotic susceptibility, BOX-PCR and MLST.ResultsTwenty-nine different serotypes were identified; serotypes 14, 19A, 12F, 5, 23F, and 1 were common and accounted for 58.3% of all serotypes overall. MLST analysis showed 72 sequence types (STs) of which 46 are novel. eBURST analysis using the stringent 6/7 identical loci definition, grouped the isolates into 17 clonal complexes and 32 singletons. The population structure of the 8 serotype 1 isolates obtained from 4 vaccinated and 2 unvaccinated children were the same (ST 618) except that one (ST3336) of the isolates from an unvaccinated child had a novel ST which is a single locus variant of ST 618.ConclusionWe provide the first background data on the genetic structure of S. pneumoniae causing IPD prior to PC7V use in The Gambia. This data will be important for assessing the impact of PC7V in post-vaccine surveillance from The Gambia.

Reassessing the Epidemiology of Human Papillomavirus Infection: Back to Basics

Reassessing the Epidemiology of Human Papillomavirus Infection: Back to Basics

Development and Evaluation of an Indirect Enzyme-Linked Immunosorbent Assay for Detection of Foot-and-Mouth Disease Virus Nonstructural Protein Antibody using a Chemically Synthesized 2B Peptide as Antigen

Forty peptides were synthesized corresponding to hydrophilic clusters of amino acids within the sequences of foot-and-mouth disease virus (FMDV) nonstructural proteins (NSP). Six peptides were studied in more detail and the most promising, a 2B peptide, was evaluated in enzyme-linked immunosorbent assay (ELISA) using sera from naive, vaccinated, and vaccinated-and-challenged cattle as well as bovine sera from field outbreaks. The performance of the new NSP peptide ELISA was compared to that of 4 commercial NSP ELISA kits. Antibody to 2B was detectable from the end of the first week to the second week after infection in most of the nonvaccinated animals and by the second to third week in vaccinated-and-challenged animals. The sensitivity of the 2B peptide ELISA was comparable to the 3ABC Ceditest (Ceditest FMDV-NS, Cedi Diagnostics B.V.; Chung et al., 2002). With some modification and further validation, this 2B test could be useful as a screening or conformational NSP test in postvaccination surveillance for FMD.