Aging is associated with an insufficient early inflammatory response of lung endothelial cells in SARS-CoV-2 infection.

Advanced age is associated with an increased susceptibility to Coronavirus Disease (COVID)-19 and more severe outcomes, although the underlying mechanisms are understudied. The lung endothelium is located next to infected epithelial cells and bystander inflammation may contribute to thromboinflammation and COVID-19-associated coagulopathy. Here, we investigated age-associated SARS-CoV-2 pathogenesis and endothelial inflammatory responses using humanized K18-hACE2 mice. Survival was reduced to 20% in aged mice (85-112 weeks) versus 50% in young mice (12-15 weeks) at 10 days post infection (dpi). Bulk RNA-sequencing of endothelial cells from mock and infected mice at 2dpi of both age groups (aged: 72-85 weeks; young: 15 weeks) showed substantially lower significant differentially regulated genes in infected aged mice than in young mice (712 versus 2294 genes). Viral recognition and anti-viral pathways such as RIG-I-like receptor signaling, NOD-like receptor signaling and interferon signaling were regulated in response to SARS-CoV-2. Young mice showed several fold higher interferon responses (Ifitm3, Ifit1, Isg15, Stat1) and interferon-induced chemokines (Cxcl10 and Cxcl11) than aged mice. Endothelial cells from infected young mice displayed elevated expression of chemokines (Cxcl9, Ccl2) and leukocyte adhesion markers (Icam1) underscoring that inflammation of lung endothelium during infection could facilitate leukocyte adhesion and thromboinflammation. TREM1 and acute phase response signaling were particularly prominent in endothelial cells from infected young mice. Immunohistochemistry was unable to detect viral protein in pulmonary endothelium. In conclusion, our data demonstrate that the early host response of the endothelium to SARS-CoV-2 infection declines with aging, which could be a potential contributor to disease severity.

Complete coding region sequence analyses and antigenic characterization of emerging lineage G-IX of foot- and-mouth disease virus serotype Asia1.

Foot-and-mouth disease Virus (FMDV) serotype Asia1 is prevalent in the Indian subcontinent, with only G-III and G-VIII reported in India until 2020. However, in 2019, a novel genetic group within serotype Asia1, designated as G-IX, emerged in Bangladesh, followed by its detection in India in 2020. This report presents analyses of the complete coding region sequences of the G-IX lineage isolates. The length of the open reading frame (ORF) of the two G-IX isolates was 6990 nucleotides without any deletion or insertion. The G-IX isolates showed the highest sequence similarity with an isolate of G-III at the ORF, L, P2, and P3 regions, and with an isolate of G-VIII at the P1 region. Phylogenetic analysis based on the capsid region (P1) supports the hypothesis that G-VIII and G-IX originated from a common ancestor, as speculated earlier. Further, VP1 region-based phylogenetic analyses revealed the re-emergence of G-VIII after a gap of 3 years. One isolate of G-VIII collected during 2023 revealed a codon insertion in the G-H loop of VP1. The vaccine matching studies support the suitability of the currently used Indian vaccine strain IND63/1972 to contain outbreaks due to viruses belonging to G-IX.

Investigating the Influence of ANTXR2 Gene Mutations on Protective Antigen Binding for Heightened Anthrax Resistance.

Bacillus anthracis is the bacterium responsible for causing the zoonotic disease called anthrax. The disease presents itself in different forms like gastrointestinal, inhalation, and cutaneous. Bacterial spores are tremendously adaptable, can persist for extended periods and occasionally endanger human health. The Anthrax Toxin Receptor-2 (ANTXR2) gene acts as membrane receptor and facilitates the entry of the anthrax toxin into host cells. Additionally, mutations in the ANTXR2 gene have been linked to various autoimmune diseases, including Hyaline Fibromatosis Syndrome (HFS), Ankylosing Spondylitis (AS), Juvenile Hyaline Fibromatosis (JHF), and Infantile Systemic Hyalinosis (ISH). This study delves into the genetic landscape of ANTXR2, aiming to comprehend its associations with diverse disorders, elucidate the impacts of its mutations, and pinpoint minimal non-pathogenic mutations capable of reducing the binding affinity of the ANTXR2 gene with the protective antigen. Recognizing the pivotal role of single-nucleotide polymorphisms (SNPs) in shaping genetic diversity, we conducted computational analyses to discern highly deleterious and tolerated non-synonymous SNPs (nsSNPs) in the ANTXR2 gene. The Mutpred2 server determined that the Arg465Trp alteration in the ANTXR2 gene leads to altered DNA binding (p = 0.22) with a probability of a deleterious mutation of 0.808; notably, among the identified deleterious SNPs, rs368288611 (Arg465Trp) stands out due to its significant impact on altering the DNA-binding ability of ANTXR2. We propose these SNPs as potential candidates for hypertension linked to the ANTXR2 gene, which is implicated in blood pressure regulation. Noteworthy among the tolerated substitutions is rs200536829 (Ala33Ser), recognized as less pathogenic; this highlights its potential as a valuable biomarker, potentially reducing side effects on the host while also reducing binding with the protective antigen protein. Investigating these SNPs holds the potential to correlate with several autoimmune disorders and mitigate the impact of anthrax disease in humans.

Estimation of foot-and-mouth disease virus sero-prevalence rates using novel computational approach for the susceptible bovine population in India during the period 2008-2021.

Foot-and-mouth disease (FMD) is a severe contagious viral disease of cloven-hoofed animals. In India, a vaccination-based official FMD control programme was started, which got expanded progressively to cover entire country in 2019. The serological tests are used to determine non-structural protein based sero-prevalence rates for properly implementing and assessing the control programme. Since 2008, reporting of the FMD sero-surveillance was limited to the serum sample-based serological test results without going for population-level estimation due to lack of proper statistical methodology. Thus, we present a computational approach for estimating the sero-prevalence rates at the state and national levels. Based on the reported approach, a web-application ( https://nifmd-bbf.icar.gov.in/FMDSeroSurv ) and an R software package ( https://github.com/sam-dfmd/FMDSeroSurv ) have been developed. The presented computational techniques are applied to the FMD sero-surveillance data during 2008-2021 to get the status of virus circulation in India under a strict vaccination policy. Furthermore, through various structural equation models, we attempt to establish a link between India's estimated sero-prevalence rate and field FMD outbreaks. Our results indicate that the current sero-prevalence rates are significantly associated with previous field outbreaks up to 2 years. Besides, we observe downward trends in sero-prevalence and outbreaks over the years, specifically after 2013, which indicate the effectiveness of various measures implemented under the FMD control programme. The findings of the study may help researchers and policymakers to track virus infection and identification of potential disease-free zones through vaccination.

A reverse transcription-multiplex PCR strategy devised for concomitant detection and differentiation of foot and mouth disease virus serotypes O, A and Asia 1 in India.

Serotype identification occupies the central part of foot and mouth disease (FMD) diagnosis workflow and vaccination decision tree. In this study, a reverse transcription-multiplex PCR (RT-mPCR) strategy wherein three assays with unique combinations of serotype specific primers targeting the VP1 region was developed to differentiate FMD virus serotypes O, A and Asia 1 based on differential size of the PCR amplicons on agarose gel. Their diagnostic performance relative to the mPCR assay in use in India was evaluated on 169 clinical samples and 210 cell culture grown virus isolates. The relative diagnostic sensitivity was found to be 99.69%, 98.78% and 99.08% for primer combinations 1, 2 and 3, respectively. These assays proved their worth by detecting serotype in three FMD suspected specimens that went undiagnosed in the existing mPCR and also by identifying multiple serotypes in the same sample. Their detection limits varied from log10 2 to log10 4 viral RNA dilution and from 100 to 0.1 TCID50 virus depending on the serotype. The validated novel mPCR assays show promise to be included in the routine diagnostic tool-box to augment the efficiency of diagnosis of FMD virus serotypes that display extreme genetic diversity and a tendency of transboundary dispersal.

Externalized histones fuel pulmonary fibrosis via a platelet-macrophage circuit of TGFß1 and IL-27.

Externalized histones erupt from the nucleus as extracellular traps, are associated with several acute and chronic lung disorders, but their implications in the molecular pathogenesis of interstitial lung disease are incompletely defined. To investigate the role and molecular mechanisms of externalized histones within the immunologic networks of pulmonary fibrosis, we studied externalized histones in human and animal bronchoalveolar lavage (BAL) samples of lung fibrosis. Neutralizing anti-histone antibodies were administered in bleomycin-induced fibrosis of C57BL/6 J mice, and subsequent studies used conditional/constitutive knockout mouse strains for TGFß and IL-27 signaling along with isolated platelets and cultured macrophages. We found that externalized histones (citH3) were significantly (P < 0.01) increased in cell-free BAL fluids of patients with idiopathic pulmonary fibrosis (IPF; n = 29) as compared to healthy controls (n = 10). The pulmonary sources of externalized histones were Ly6G+CD11b+ neutrophils and nonhematopoietic cells after bleomycin in mice. Neutralizing monoclonal anti-histone H2A/H4 antibodies reduced the pulmonary collagen accumulation and hydroxyproline concentration. Histones activated platelets to release TGFß1, which signaled through the TGFbRI/TGFbRII receptor complex on LysM+ cells to antagonize macrophage-derived IL-27 production. TGFß1 evoked multiple downstream mechanisms in macrophages, including p38 MAPK, tristetraprolin, IL-10, and binding of SMAD3 to the IL-27 promotor regions. IL-27RA-deficient mice displayed more severe collagen depositions suggesting that intact IL-27 signaling limits fibrosis. In conclusion, externalized histones inactivate a safety switch of antifibrotic, macrophage-derived IL-27 by boosting platelet-derived TGFß1. Externalized histones are accessible to neutralizing antibodies for improving the severity of experimental pulmonary fibrosis.

Foot-and-Mouth Disease Virus Serotype O Exhibits Phenomenal Genetic Lineage Diversity in India during 2018-2022.

In India, widespread foot-and-mouth disease (FMD) outbreaks occurred in 2021. The objective of this study was to identify genetic lineages and evaluate the antigenic relationships of FMD virus (FMDV) isolates gathered from outbreaks reported between 2019 and 2022. Our study shows that the lineages O/ME-SA/Ind2001e and the O/ME-SA/Cluster-2018 were both responsible for the FMD outbreaks on an epidemic scale during 2021. This observation is in contrast to earlier findings that suggested epidemic-scale FMD outbreaks in India are often connected to a single genetic lineage. Additionally, we report here the identification of the O/ME-SA/PanAsia-2/ANT10 sub-lineage in India for the first time, which was connected to two intermittent outbreaks in Jammu and Kashmir. The current study demonstrates that the O/ME-SA/ind2001e lineage has a strong presence outside of the Indian subcontinent. Furthermore, the O/ME-SA/Cluster-2018 was observed to have a wider geographic distribution than previously, and like the O/ME-SA/Ind2001d and O/ME-SA/Ind2001e lineages in the past, it may eventually spread outside of its geographic niche. For O/ME-SA/Ind2001e and O/ME-SA/Cluster-2018, the predicted substitution rate for the VP1 region was 6.737 × 10-3 and 8.257 × 10-3 nt substitutions per site per year, respectively. The time of the most recent common ancestor of the O/ME-SA/Ind2001e and O/ME-SA/Cluster-2018 strains suggests that the viruses possibly emerged during 2003-2011 and 2009-2017, respectively. Recent sightings of the O/ME-SA/PanAsia2/ANT10 virus in India and the O/ME-SA/Ind2001e virus in Pakistan point to possible cross-border transit of the viruses. The results of a two-dimensional viral neutralization test revealed that all of the field isolates were antigenically matched to the currently used Indian vaccine strain O INDR2/1975. These results suggest that the serotype O vaccine strain can protect against outbreaks brought on by all three circulating lineages.

Novel pan-lineage VP1 specific degenerate primers for precise genetic characterization of serotype O foot and mouth disease virus circulating in India.

Analysis of the VP1 gene sequence of the foot and mouth disease virus (FMDV) is critical to understanding viral evolution and disease epidemiology. A standard set of primers have been used for the detection and sequence analysis of the VP1 gene of FMDV directly from suspected clinical samples with limited success. The study validated VP1-specific degenerate primer-based reverse transcription polymerase chain reaction (RT-PCR) for the qualitative detection and sequencing of serotype O FMDV lineages circulating in India. The novel degenerate primer-based RT-PCR amplifying the VP1 gene can circumvent the genetic heterogeneity observed in viruses after cell culture adaptation and facilitate precise viral gene sequence analysis from clinical samples.

Emergence of a novel genetic lineage 'A/ASIA/G-18/2019' of foot and mouth disease virus serotype A in India: A challenge to reckon with.

Foot and mouth disease (FMD) has engendered large scale socioeconomic crises on numerous occasions owing to its extreme contagiousness, transboundary nature, complicated epidemiology, negative impact on productivity, trade embargo, and need for intensive surveillance and expensive control measures. Emerging FMD virus variants have been predicted to have originated and spread from endemic Pool 2, native to South Asia, to other parts of the globe. In this study, 26 Indian serotype A isolates sampled between the year 2015 and 2022 were sequenced for the VP1 region. BLAST and maximum likelihood phylogeny suggest emergence of a novel genetic group within genotype 18, named here as 'A/ASIA/G-18/2019' lineage, that is restricted so far only to India and its eastern neighbour, Bangladesh. The lineage subsequent to its first appearance in 2019 seems to have displaced all other prevalent strains, in support of the phenomenon of 'genotype/lineage turnover'. It has diversified into two distinct sub-clusters, reflecting a phase of active evolution. The rate of evolution of the VP1 region for the Indian serotype A dataset was estimated to be 6.747 × 10-3 substitutions/site/year. India is implementing a vaccination centric FMD control programme. The novel lineage showed good antigenic match with the proposed vaccine candidate A IND 27/2011 when tested in virus neutralization test, while the existing vaccine strain A IND 40/2000 showed homology with only 31% of the isolates. Therefore, in order to combat this challenge of antigenic divergence, A IND 27/2011 could be the preferred strain in the Indian vaccine formulations.

Whole-Genome-Sequence-Based Evolutionary Analyses of HoBi-like Pestiviruses Reveal Insights into Their Origin and Evolutionary History.

HoBi-like pestivirus (HoBiPeV), classified under Pestivirus H species, is an emerging cattle pathogen of high economic impact. However, the origin and evolution of HoBiPeV are not very clear due to a lack of full genomic sequences from diverse clades. This study aimed to determine full-genome sequences of HoBiPeV strains of three novel clades (c, d and e) and perform full-genome-based genetic and evolutionary analyses. Bayesian phylogenetic analyses herein confirmed the existence and independent evolution of four main HoBiPeV clades (a, c, d and e) globally, with genetic divergence ranging from 13.0% to 18.2%. Our Bayesian molecular clock estimates revealed that HoBiPeV most likely originated in India, with a dated tMRCA of 1938 (1762-2000), evidencing a more recent origin of HoBiPeV. The evolution rate of HoBiPeV was estimated to be 2.133 × 10-3 subs/site/year at full-genome level but varied widely among individual genes. Selection pressure analyses identified most of the positively selected sites in E2. Additionally, 21.8% of the ORF codon sites were found under strong episodic diversifying selection, providing first evidence of negative selection in HoBiPeV evolution. No recombination event was evident for HoBiPeV-c, d and e strains. These findings provide new insights into HoBiPeV origin and evolutionary history for better understanding the epidemiology and host-pathogen interactions and stimulate vaccine research.

A single amino acid substitution in the VP2 protein of Indian foot-and-mouth disease virus serotype O vaccine strain confers thermostability and protective immunity in cattle.

Foot-and-mouth disease (FMD) is a significant threat to animal health globally. Prophylactic vaccination using inactivated FMD virus (FMDV) antigen is being practised for the control in endemic countries. A major limitation of the current vaccine is its susceptibility to high environmental temperature causing loss of immunogenicity, thus necessitating the cold chain for maintenance of its efficacy. Hence, the FMD vaccine with thermostable virus particles will be highly useful in sustaining the integrity of whole virus particle (146S) during storage at 4°C. In this study, 12 recombinant mutants of Indian vaccine strain of FMDV serotype O (O/IND/R2/1975) were generated through reverse genetics approach and evaluated for thermostability. One of the mutant viruses, VP2_Y98F was more thermostable than other mutants and the parent FMDV. The oil-adjuvanted vaccine formulated with the inactivated VP2_Y98F mutant FMDV was stable up to 8 months when stored at 4°C and induced protective antibody response till dpv 180 after primary vaccination. It is concluded that the VP2_Y98F mutant FMDV was thermostable and has the potential to replace the parent vaccine strain.

Tissue factor in COVID-19-associated coagulopathy.

Evidence of micro- and macro-thrombi in the arteries and veins of critically ill COVID-19 patients and in autopsies highlight the occurrence of COVID-19-associated coagulopathy (CAC). Clinical findings of critically ill COVID-19 patients point to various mechanisms for CAC; however, the definitive underlying cause is unclear. Multiple factors may contribute to the prothrombotic state in patients with COVID-19. Aberrant expression of tissue factor (TF), an initiator of the extrinsic coagulation pathway, leads to thrombotic complications during injury, inflammation, and infections. Clinical evidence suggests that TF-dependent coagulation activation likely plays a role in CAC. Multiple factors could trigger abnormal TF expression and coagulation activation in patients with severe COVID-19 infection. Proinflammatory cytokines that are highly elevated in COVID-19 (IL-1ß, IL-6 and TNF-α) are known induce TF expression on leukocytes (e.g. monocytes, macrophages) and non-immune cells (e.g. endothelium, epithelium) in other conditions. Antiphospholipid antibodies, TF-positive extracellular vesicles, pattern recognition receptor (PRR) pathways and complement activation are all candidate factors that could trigger TF-dependent procoagulant activity. In addition, coagulation factors, such as thrombin, may further potentiate the induction of TF via protease-activated receptors on cells. In this systematic review, with other viral infections, we discuss potential mechanisms and cell-type-specific expressions of TF during SARS-CoV-2 infection and its role in the development of CAC.

Foot-and-mouth disease status in India during the second decade of the twenty-first century (2011-2020).

Foot-and-mouth disease (FMD) is a major disease of livestock in India and causes huge economic losses. The formal FMD control program started in 2003-04 in selected districts and was gradually expanded. The present study provides a descriptive review of the FMD outbreaks, prevalent serotypes, and genetic and antigenic features of the FMD virus (FMDV) that circulated in the country between 2011 and 2020. FMD outbreaks were regularly reported in cloven-hoofed domestic livestock and wildlife, with three serotypes including O, A, and Asia1. During the study period, a total of 2226 FMD outbreaks were documented and serotypes confirmed. FMDV serotype O dominated the outbreak scenario, accounting for about 92% of all outbreaks, followed by Asia1 (5% of all outbreaks) and A (3% of all outbreaks). Two major epidemics of FMD on an unprecedented scale during the years 2013 and 2018 by serotype O were recorded. The spatial distribution of FMD was characterized by a larger number of outbreaks in the southern region of the country. In an annual-scale analysis, 2020 was the year with the lowest outbreaks, and 2013 was the year with the highest. The month-scale analysis showed that outbreaks were reported throughout the year, with the highest numbers between October and March. The emergence of three major lineages (O/ME-SA/Ind2001d, O/ME-SA/Ind2001e, and O/ME-SA/Ind2018) of serotype O was observed during the period. In the cases of serotype A and Asia1, the appearance of at least one novel lineage/genetic group, including A/G-18/non-deletion/2019 and Asia1/Group-IX, was documented. While serotype A showed the advent of antigenic variants, serotypes O and Asia1 did not show any antigenic diversity. It was noticed during the course of an outbreak that animal movement contributes significantly to disease transmission. Except for 2018, when numerous FMD outbreaks were recorded, the number of annual outbreaks reported after 2016 has been lower than in the first half of the decade, probably due to mass vaccination and COVID-19 pandemic-linked movement restrictions. Even during outbreaks, disease symptoms in ruminant populations, including cattle, were found to be less severe. Regular six-monthly immunization certainly has a positive impact on the reduction of disease burden and should be followed without fail and delay, along with intensive disease surveillance.

An extensive analysis of Codon usage pattern, Evolutionary rate, and Phylogeographic reconstruction in Foot and mouth disease (FMD) serotypes (A, Asia 1, and O) of six major climatic zones of India: A comparative study.

Foot and mouth disease (FMD) is a major economically important viral disease of cloven-hoofed livestock globally. The FMD virus (FMDV) spreads widely in confined, cool, and humid climatic conditions. Being an RNA virus, FMDV is genetically unstable, and its genome evolution is highly influenced by mutational pressure. The climatic and environmental conditions have a significant impact on mutational pressure. The present study is a primary effort to establish a comprehensive relationship between climatic factors and the molecular evolutionary pattern of serotypes FMDV circulating in India. In this study, isolates of three serotypes (A, Asia 1, and O) were selected from six major climatic zones of India (Montane, Humid subtropical, Tropical wet and dry, Tropical wet, Semi-arid and Arid). Based on the full genome nucleotide sequence data, the codon usage bias, evolutionary and phylogeographic analysis was carried out. The study revealed that the codon use bias indicators in the FMDV serotypes differed significantly depending on the climatic zones. It implies that the selection and mutational pressure influence the codon usage pattern indices, with mutational pressure taking precedence in determining the codon usage bias of the FMDV genome. The tMRCA was estimated to be 1977, 1956, and 1953 for Indian FMD virus serotype-A, Asia 1, and O respectively which is around 32, 60, and 61 years before its actual identification in the field. Based on the evolutionary rates the serotype O is evolving rapidly compare to other serotypes in India. Virus transmission across the region was evident from the phylogeographic analysis. The integrated analysis of codon usage bias, evolutionary rate, and phylogeography analysis signifies the major role of mutational and selection pressure, implying that the FMD virus co-evolution and adaptations are highly influenced by climatic/environmental factors.

Coagulation Factor IIIa (f3a) Knockdown in Zebrafish Leads to Defective Angiogenesis and Mild Bleeding Phenotype.

Tissue factor (TF) is crucial for embryogenesis, as mice lacking TF are embryonically lethal (E10.5). This lethality may be attributed to defects in vascular development and circulatory failure, suggesting additional roles for TF in embryonic development beyond coagulation. In this study, we characterized the role of one of the TF paralogs (f3a) using a zebrafish model. The expression of f3a during embryonic developmental stages was determined by RT-PCR. Spatiotemporal expression pattern of f3a revealed (high expression from 28 to 36 hpf) the role of in the development of the yolk sac, circulation, and fins. Morpholinos (MO), an antisense-based oligonucleotide strategy, was used to knockdown f3a and examined for defects in morphological appearance, bleeding, and vascular patterning. f3a MO-injected embryos showed morphological abnormalities, including shorter body lengths and crooked tails. O-dianisidine staining showed f3a MO-injected embryos exhibited bleeding in the trunk (5.44%) and head (9.52%) regions. Imaging of endothelial-specific transgenic lines (flk1:egfp-NLS/kdrl:mCherry-CAAX) showed a 3-fold decreased caudal vein plexus (CVP) in f3a morphants versus controls at 48 hpf, suggesting a potential role for f3a in angiogenesis. These findings confirm that f3a is essential for angiogenesis, in addition to its involvement in hemostasis.

Fatal Neurodissemination and SARS-CoV-2 Tropism in K18-hACE2 Mice Is Only Partially Dependent on hACE2 Expression.

Animal models recapitulating COVID-19 are critical to enhance our understanding of SARS-CoV-2 pathogenesis. Intranasally inoculated transgenic mice expressing human angiotensin-converting enzyme 2 under the cytokeratin 18 promoter (K18-hACE2) represent a lethal model of SARS-CoV-2 infection. We evaluated the clinical and virological dynamics of SARS-CoV-2 using two intranasal doses (104 and 106 PFUs), with a detailed spatiotemporal pathologic analysis of the 106 dose cohort. Despite generally mild-to-moderate pneumonia, clinical decline resulting in euthanasia or death was commonly associated with hypothermia and viral neurodissemination independent of inoculation dose. Neuroinvasion was first observed at 4 days post-infection, initially restricted to the olfactory bulb suggesting axonal transport via the olfactory neuroepithelium as the earliest portal of entry. Absence of viremia suggests neuroinvasion occurs independently of transport across the blood-brain barrier. SARS-CoV-2 tropism was neither restricted to ACE2-expressing cells (e.g., AT1 pneumocytes), nor inclusive of some ACE2-positive cell lineages (e.g., bronchiolar epithelium and brain vasculature). Absence of detectable ACE2 protein expression in neurons but overexpression in neuroepithelium suggest this as the most likely portal of neuroinvasion, with subsequent ACE2 independent lethal neurodissemination. A paucity of epidemiological data and contradicting evidence for neuroinvasion and neurodissemination in humans call into question the translational relevance of this model.

Impact of mass vaccination on the spatiotemporal dynamics of FMD outbreaks in India, 2008-2016.

Foot-and-mouth disease (FMD) is endemic in India, where circulation of serotypes O, A and Asia1 is frequent. Here, we provide an epidemiological assessment of the ongoing mass vaccination programs in regard to post-vaccination monitoring and outbreak occurrence. The objective of this study was assessing the contribution of mass vaccination campaigns in reducing the risk of FMD in India from 2008 to 2016 by evaluating sero-monitoring data and modelling the spatiotemporal dynamics of reported outbreaks. Through analyzing antibody titre data from >1 million animals sampled as part of pre- and post-vaccination monitoring, we show that the percent of animals with inferred immunological protection (based on ELISA) was highly variable across states but generally increased through time. In addition, the number of outbreaks in a state was negatively correlated with the percent of animals with inferred protection. We then analyzed the distribution of reported FMD outbreaks across states using a Bayesian space-time model. This approach provides better acuity to disentangle the effect of mass vaccination programs on outbreak occurrence, while accounting for other factors that contribute to spatiotemporal variability in outbreak counts, notably proximity to international borders and inherent spatiotemporal correlations in incidence. This model demonstrated a ∼50% reduction in the risk of outbreaks in states that were part of the vaccination program. In addition, after controlling for spatial autocorrelation in the data, states that had international borders experienced heightened risk of FMD outbreaks. These findings help inform risk-based control strategies for India as the country progresses towards reducing reported clinical disease.

Assessment of fitness of foot-and-mouth disease virus A IND 27/2011 as candidate vaccine strain.

Antigenic profiling of recent field outbreak strains of foot-and-mouth disease virus (FMDV) serotype A in India has revealed considerable antigenic drift from the vaccine strain, A IND 40/2000, necessitating the selection of a new strain. The complete genome sequence of A IND 27/2011 was analysed. Vaccine quality attributes of the new candidate strain including potency as an inactivated vaccine in cattle were evaluated. The capsid coding region of A IND 27/2011 showed variation at eight antigenically critical amino acid positions from that of A IND 40/2000. The strain suited well with traits required by a vaccine in terms of its adaptability to adherent and suspension cell line, its immunogenicity, and potency as an inactivated vaccine formulation in cattle. Complete protection was observed upon homologous virus challenge at 4 weeks post-vaccination. Taken together, these data demonstrate the suitability of A IND 27/2011 as an effective vaccine strain of FMDV serotype A.