Measles Vaccine-Associated Rash Illness in China: an Emerging Issue in the Process of Measles Elimination
JOURNAL OF CLINICAL MICROBIOLOGY
Authors: Cui, Aili; Wang, Huiling; Zhu, Zhen; Mao, Naiying; Song, Jinhua; Zhang, Yan; Xu, Wenbo
Abstract
Along with the implementation of measles case-based surveillance, measles vaccine-associated rash illness (VARI) cases were detected in China. To better understand the characteristics of VARI, 101 VARI cases confirmed by measles virus genotyping in 2011 to 2018 were analyzed in this study. With the decrease in measles incidence, the detection rate of VARI cases increased among the cases confirmed by genotyping. Compared with genotype H1 wild-type measles, VARI occurred throughout the year, without obvious seasonal distribution. Infants and children of ages 8 to 23 months were the main population of VARI. VARI mainly occurred within 14 days after measles vaccination. The number of VARI cases peaked on the 8th day after measles vaccination, which was later than that of genotype H1 wild-type measles cases with a measles vaccination history. VARI presents clinical symptoms similar to those of measles. The frequencies of the "3Cs" (cough, coryza, and conjunctivitis), Koplik spots, and complications in VARI cases were significantly lower than those in wild-type measles cases. In total, 94.06% of sequences from VARI cases were identical to measles vaccine strain S191 in the C-terminal 450-nucleotide sequence of the nucleoprotein (N-450) gene. A few substitutions were found in N-450 sequences of the VARI cases. The confirmation of VARI has become an emerging issue in the process of measles elimination. Rapid confirmation of VARI is critical for measles surveillance and will help to determine the response measures for measles, especially in measles preelimination and elimination settings. The suspected measles cases with measles-containing vaccine (MCV) vaccination were recommended to be tested by the laboratory to identify wild-type measles or VARI.
Understanding Intramolecular Crosstalk in an Intrinsically Disordered Protein
ACS CHEMICAL BIOLOGY
Authors: Troilo, Francesca; Bonetti, Daniela; Bignon, Christophe; Longhi, Sonia; Gianni, Stefano
Abstract
The interaction between NTAIL and XD from the measles virus represents a paradigmatic example of molecular recognition between an intrinsically disordered protein and a folded partner. By binding to XD, a small portion of NTAff, (classically denoted as MoRE) undergoes a disorder-to-order transition, populating an alpha-helical structure, while the reminder of the protein remains disordered. Here, we demonstrate an unexpected crosstalk between such a disordered region and the adjacent molecular recognition element (MoRE). This result was obtained by producing a series of truncation and site-directed variants of NTAIL while measuring the effects on the kinetics of folding and binding. We show that the disordered region of NTAIL exerts its inhibitory role by slowing the folding step of the MoRE, thereby tuning the affinity of the interaction.