459 infections and 178 deaths is the latest information coming out of Angola, where an outbreak of Yellow Fever was first reported in the capital city, Luanda, in December 2015, the first outbreak of the disease in three decades, and has now spread out to ten of the country's eighteen provinces. Worse, the outbreak is reaching neighboring countries, with cases reported in the Democratic Republic of Congo, Zambia and Namibia. Other cases in Kenya and the People's Republic of China have been described as travel-related cases with links to Angola. A massive vaccination campaign was launched by the health authorities and the National Response Plan saw 87 per cent of the targeted 6.4 million people at risk vaccinated, as 7.3 million doses of the vaccine were made available with help from countries such as Brazil, the World Health Organization and the International Coordinating Group for yellow fever vaccine provision.

Cameroon has started immunizing children and adults against yellow fever (!--ref1--) in Douala, the commercial hub, following confirmed cases as part of a preventive response intervention.

Westminster : printed by F. Hayden, [1839]

Title: Yellow Fever Outbreak: Is the U.S. at Risk?
Category: Health News
Created: 4/29/2016 12:00:00 AM
Last Editorial Review: 4/29/2016 12:00:00 AM

Title: U.S. Moves to Avert Shortage of Yellow Fever Vaccine
Category: Health News
Created: 4/28/2017 12:00:00 AM
Last Editorial Review: 5/1/2017 12:00:00 AM

ABSTRACT

Recent outbreaks of yellow fever virus (YFV) in West Africa and Brazil resulted in rapid depletion of global vaccine emergency stockpiles and raised concerns about being unprepared against future YFV epidemics. Here we report that a live attenuated virus similar to the Japanese encephalitis virus (JEV) vaccine JE-CVax/Imojev that consists of YFV-17D vaccine from which the structural (prM/E) genes have been replaced with those of the JEV SA14-14-2 vaccine strain confers full protection in mice against lethal YFV challenge. In contrast to the YFV-17D-mediated protection against YFV, this protection is not mediated by neutralizing antibodies but correlates with YFV-specific nonneutralizing antibodies and T cell responses against cell-associated YFV NS1 and other YFV nonstructural (NS) proteins. Our findings reveal the potential of YFV NS proteins to mediate protection and demonstrate that chimeric flavivirus vaccines, such as Imojev, could confer protection against two flaviviruses. This dual protection may have implications for the possible off-label use of JE-CVax in case of emergency and vaccine shortage during YFV outbreaks. In addition, populations in Asia that have been vaccinated with Imojev may already be protected against YFV should outbreaks ever occur on that continent, as several countries/regions in the Asia-Pacific are vulnerable to international spread of the YFV.

IMPORTANCE Efficient and safe vaccines against yellow fever (e.g., YFV-17D) that provide long-lasting protection by rapidly inducing neutralizing antibody responses exist. However, the vaccine supply cannot cope with an increasing demand posed by urban outbreaks in recent years. Here we report that JE-CVax/Imojev, a YFV-17D-based chimeric Japanese encephalitis vaccine, also efficiently protects against YFV infection in mice. In case of shortage of the YFV vaccine during yellow fever outbreaks, (off-label) use of JE-CVax/Imojev may be considered. Moreover, wider use of JE-CVax/Imojev in Asia may lower the risk of the much-feared YFV spillover to the continent. More generally, chimeric vaccines that combine surface antigens and replication machineries of two distinct flaviviruses may be considered dual vaccines for the latter pathogen without induction of surface-specific antibodies. Following this rationale, novel flavivirus vaccines that do not hold a risk for antibody-dependent enhancement (ADE) of infection (inherent to current dengue vaccines and dengue vaccine candidates) could be designed.

ABSTRACT

While the basic mechanisms of flavivirus entry and fusion are understood, little is known about the postfusion events that precede RNA replication, such as nucleocapsid disassembly. We describe here a sensitive, conditionally replication-defective yellow fever virus (YFV) entry reporter, YFVSK/Nluc, to quantitively monitor the translation of incoming, virus particle-delivered genomes. We validated that YFVSK/Nluc gene expression can be neutralized by YFV-specific antisera and requires known flavivirus entry pathways and cellular factors, including clathrin- and dynamin-mediated endocytosis, endosomal acidification, YFV E glycoprotein-mediated fusion, and cellular LY6E and RPLP1 expression. The initial round of YFV translation was shown to require cellular ubiquitylation, consistent with recent findings that dengue virus capsid protein must be ubiquitylated in order for nucleocapsid uncoating to occur. Importantly, translation of incoming YFV genomes also required valosin-containing protein (VCP)/p97, a cellular ATPase that unfolds and extracts ubiquitylated client proteins from large complexes. RNA transfection and washout experiments showed that VCP/p97 functions at a postfusion, pretranslation step in YFV entry. Finally, VCP/p97 activity was required by other flaviviruses in mammalian cells and by YFV in mosquito cells. Together, these data support a critical role for VCP/p97 in the disassembly of incoming flavivirus nucleocapsids during a postfusion step in virus entry.

IMPORTANCE Flaviviruses are an important group of RNA viruses that cause significant human disease. The mechanisms by which flavivirus nucleocapsids are disassembled during virus entry remain unclear. Here, we used a yellow fever virus entry reporter, which expresses a sensitive reporter enzyme but does not replicate, to show that nucleocapsid disassembly requires the cellular protein-disaggregating enzyme valosin-containing protein, also known as p97.

Objective

To determine whether live-attenuated yellow fever vaccine (YFV) was associated with MS relapse, we evaluated the clinical courses of 23 patients in the year before and the year after immunization at the university hospital of Geneva, Switzerland.

Health officials say they discovered Aedes aegypti mosquitoes - known to carry Zika virus and dengue - in York County, Nebraska, on Tuesday . It's the first time they've been seen in the state.

Every year when the seasons change from cold to warm, I get sick. Usually it’s allergies or a cold, but like clockwork I am out of commission for a few days. I suspect this has happened to people since time began, but if you lived on Manhattan Island during the 1790s, and even as late...

The post Spreading the News of Yellow Fever appeared first on New-York Historical Society.

Interview with Daniel Vitor Vasconcelos-Santos, MD PhD, author of Characterization of Retinopathy Among Patients With Yellow Fever During 2 Outbreaks in Southeastern Brazil