In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

[EX Q]: Despite the clinical relevance, dengue virus (DENV) research has been hampered by the absence of robust reverse genetic systems to manipulate the viral serotypes for propagation and generation of mutant viruses. In this article, we describe application of an infectious clone system for DENV serotype 1 (DENV1). Similar to previous clones in both flaviviruses and coronaviruses, the approach constructs a panel of contiguous cDNAs that span the DENV genome and can be systematically and directionally assembled to produce viable, full-length viruses. Comparison of the virus derived from the infectious clone with the original viral isolate reveals identical sequence, comparable endpoint titers, and similar focus staining. Both focus-forming assays and percent infection by flow cytometry revealed overlapping replication levels in two different cell types. Moreover, serotype-specific monoclonal antibodies (MAbs) bound similarly to infectious clone and the natural isolate. Using the clone, we were able to insert a DENV4 type-specific epitope recognized by primate MAb 5H2 into envelope (E) protein domain I (EDI) of DENV1 and recover a viable chimeric recombinant virus. The recombinant DENV1 virus was recognized and neutralized by the DENV4 type-specific 5H2 MAb. The introduction of the 5H2 epitope ablated two epitopes on DENV1 EDI recognized by human MAbs (1F4 and 14C10) that strongly neutralize DENV1. Together, the work demonstrates the utility of the infectious clone and provides a resource to rapidly manipulate the DENV1 serotype for generation of recombinant and mutant viruses.
[EX A]: Epitope Addition and Ablation via Manipulation of a Dengue Virus Serotype 1 Infectious Clone

[EX Q]: Understanding viral transmission dynamics within populations of reservoir hosts can facilitate greater knowledge of the spillover of emerging infectious diseases. While bat-borne viruses are of concern to public health, investigations into their dynamics have been limited by a lack of longitudinal data from individual bats. Here, we examine capture-mark-recapture (CMR) data from a species of Australian bat (Myotis macropus) infected with a putative novel Alphacoronavirus within a Bayesian framework. Then, we developed epidemic models to estimate the effect of persistently infectious individuals (which shed viruses for extensive periods) on the probability of viral maintenance within the study population. We found that the CMR data analysis supported grouping of infectious bats into persistently and transiently infectious bats. Maintenance of coronavirus within the study population was more likely in an epidemic model that included both persistently and transiently infectious bats, compared with the epidemic model with non-grouping of bats. These findings, using rare CMR data from longitudinal samples of individual bats, increase our understanding of transmission dynamics of bat viral infectious diseases.
[EX A]: Persistent infections support maintenance of a coronavirus in a population of Australian bats (Myotis macropus)

[EX Q]: Background: Host genetic factors may play a role in susceptibility and resistance to SARS associated coronavirus (SARS-CoV) infection. The study was carried out to investigate the association between the genetic polymorphisms of 2',5'-oligoadenylate synthetase 1 (OAS1) gene as well as myxovirus resistance 1 (MxA) gene and susceptibility to SARS in Chinese Han population. A hospital-based case-control study was conducted. A collective of 66 SARS cases and 64 close contact uninfected controls were enrolled in this study. End point real time polymerase chain reaction (PCR) and PCR-based Restriction Fragment Length Polymorphism (RFLP) analysis were used to detect the single nucleic polymorphisms (SNPs) in OAS1 and MxA genes. Information on other factors associated with SARS infection was collected using a pre-tested questionnaire. Univariate and multivariate logistic analyses were conducted. Results: One polymorphism in the 3'-untranslated region (3'-UTR) of the OAS1 gene was associated with SARS infection. Compared to AA genotype, AG and GG genotypes were found associated with a protective effect on SARS infection with ORs (95% CI) of 0.42 (0.20~0.89) and 0.30 (0.09~0.97), respectively. Also, a GT genotype at position 88 in the MxA gene promoter was associated with increased susceptibility to SARS infection compared to a GG genotype (OR = 3.06, 95% CI: 1.25~7.50). The associations of AG genotype in OAS1 and GT genotype in MxA remained significant in multivariate analyses after adjusting for SARS protective measures (OR = 0.38, 95% CI: 0.14~0.98 and OR = 3.22, 95% CI: 1.13~9.18, respectively). Conclusion: SNPs in the OAS1 3'-UTR and MxA promoter region appear associated with host susceptibility to SARS in Chinese Han population.
[EX A]:
BMC Infectious Diseases Association of SARS susceptibility with single nucleic acid polymorphisms of OAS1 and MxA genes: a case-control study