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CIDRAP NEWS SCAN: Zika pregnancy lab findings; MERS family cluster probe; Ebola vaccine developments; HPV vaccine safety

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  • CIDRAP NEWS SCAN: Zika pregnancy lab findings; MERS family cluster probe; Ebola vaccine developments; HPV vaccine safety

    Source: http://www.cidrap.umn.edu/news-persp...an-jul-18-2016

    News Scan for Jul 18, 2016
    Zika pregnancy lab findings; MERS family cluster probe; Ebola vaccine developments; HPV vaccine safety

    Filed Under:
    Zika; MERS-CoV; Ebola; VHF; Human Papillomavirus (HPV)

    Experiments shed light on how Zika viruses infect, cause birth defects

    In the latest round of lab studies to pinpoint how Zika virus infects and causes birth defects in fetuses, researchers today reported several new clues related to the route and timing of infection, differences between the two viral strains, and even an antibiotic with the potential to block some of the damage.
    A group from the University of California at San Francisco and the University of California at Berkeley reported their findings today in Cell Host and Microbe. Their work with cells grown from the human placenta suggested that the cells are very vulnerable during the first trimester, though the surface wasn't infected, leaving questions about how Zika cells from the mother cross the placenta during that stage.
    Their tests on cells and tissues of the amniotic sac, however, suggested that during the second and third trimesters Zika virus can infect the outside of the structure, where it can infiltrate the fluid and cause systemic fetal infections through the skin. Also, the researchers found clues of higher Zika virus loads during the middle part of pregnancy, when compared with later, which hints that damage could relate to how long the fetus is exposed to Zika virus.
    In experiments with the two different Zika strains, the African one and the one causing the outbreaks in the Americas, the group found that both are capable of infecting placental and amniotic sac cells and tissues, but infections with the Americas strain triggered higher levels of virus.
    In looking for a common theme in the cells that were vulnerable to Zika virus, the researchers found that all contained the protein TIM1. The discovery led them to a recent report that the antibiotic duramycin, recently reported to block cell attachment of two other flaviriviruses? dengue and West Nile virus. When the team tested the drug against Zika virus, they found that it greatly curbed Zika infection and replication.
    Jul 18 Cell Host Microb abstract

    Close contact, caregiving fueled MERS spread in large family cluster

    A detailed investigation of a large family cluster of MERS in Saudi Arabia revealed that those who got sick were more likely to be older and male and have underlying health conditions, and that people who slept in infected patients' rooms and touched their respiratory secretions were more likely to become ill.
    The cluster emerged in Jeddah in May 2014, with 19 of 79 family members testing positive for the virus. Researchers from the US Centers for Disease Control and Prevention (CDC) and their Saudi collaborators described the findings Jul 15 in Emerging Infectious Diseases.
    Of relatives interviewed and tested, 50 lived in the original four households, 26 were visitors, and 3 were adults from a separate branch of the family tree. Testing done as part of the outbreak response found that 11 were positive on reverse-transcription polymerase chain reaction (RT-PCR) tests and 8 were positive on serology testing. Of the 19 sick people, 11 were hospitalized and 2 died. All 26 of the visitors tested negative on the MERS-CoV (Middle East respiratory syndrome coronavirus) tests.
    The researchers found that transmission didn't seem to be linked simply to proximity, but close contact and direct patient care did emerge as risk factors. Only three of the patients were women, all of them wives of sick individuals. The investigators said the low number of infected women might reflect biologic or behavioral differences, such as women socializing separately.
    Initial RT-PCR tests were negative for 8 of the 19 patients while they were ill or after exposure was noted. The team said that finding suggests that serology may be more sensitive and should be considered as a testing method in future outbreak investigations.
    Jul 15 Emerg Infect Dis study

    Groups report early results in animals for two candidate Ebola vaccines

    Two companies recently announced promising findings from early animal studies for Ebola vaccine candidates, one of them a heat-stable subunit vaccine and the other an adjuvanted virus-like particle (VLP) vaccine.
    Soligenix, based in Princeton, N.J., said today that the heat-stable Ebola vaccine formulation that it is developing with scientists in Hawaii and Colorado has shown proof-of-concept efficacy in nonhuman primates. The vaccine uses the proprietary ThermoVax technology, licensed from the University of Colorado and used in the development of ricin, anthrax, and human papillomavirus (HPV) subunit vaccines.
    Experiments involved a version of the vaccine that can be stored at 104?F for 12 weeks. Early testing showed that two doses of the vaccine were as effective as three doses of a nonstabilized vaccine. More studies are planned to evaluate the vaccine's protection, the company said in its statement.
    Axel Lehrer, PhD, with the John A. Burns School of Medicine at the University of Hawaii and Hawaii Biotech, Inc., said in the statement that other Ebola vaccines in development can't withstand high temperatures, a concern in parts of the world where filoviruses are endemic. He said the heat-stable vaccine the team is working on could help not only with logistics, but it also offers the potential of reaching more people with fewer vaccine doses.
    Jul 18 Soligenix press release
    Meanwhile, Yisheng Biopharma, based in China, and the US Army Medical Research Institute of Infectious Diseases (USAMRIID), recently announced early promising results for rodent studies on a VLP Ebola vaccine used with PIKA adjuvant, a toll-like receptor 3 (TLR3) agonist. The study was part of a cooperative agreement between the two groups, with the vaccine's VLP component developed by USAMRIID and the PIKA adjuvant developed by Yisheng, according to a Jul 14 news release.
    In the rodent experiments, researchers compared immunogenicity and protection of the VLP candidate vaccine with and without the adjuvant. In the challenge part of the study, 40% of the animals immunized without the adjuvant survived, and the adjuvanted vaccine showed 100% protection at both high and low doses of the PIKA adjuvant.
    The groups said the higher survival in the adjuvanted group was consistent with significantly higher antibody titers when measured against the unadjuvanted group.
    Jul 14 Yishing Biopharma-USAMRIID press release

    Meta-analysis of 9-valent HPV vaccine reveals solid safety profile

    An analysis of seven phase 3 clinical trials for the 9-valent HPV (9vHPV) vaccine encompassing about 15,000 females and males ages 9 to 26 years old found that it had a similar adverse effect profile as the quadrivalent HPV vaccine. An international research group published their findings Jul 15 in Pediatrics.
    The 9vHPV vaccine, developed by Merck and licensed in the United States in 2014, includes the strains covered by the quadrivalent vaccine plus the next five most common cancer-causing types.
    Each of the studies looked at the three-dose vaccination regimen given intramuscularly at day 1, with follow-up doses at months 2 and 6. Study participants were from 31 countries, and nearly 80% were female.
    The most common adverse event?experienced by 5% or less of the study participants?was injection-site pain, swelling, or redness. It was more common in the 9vHPV recipients than in those who received the quadrivalent vaccine, increasing with subsequent doses and at mild-to-moderate intensity. No clear pattern was seen with systemic effects, and syncope episodes were rare and did not recur. No anaphylactic reactions were reported.
    The researchers concluded that the extra protection afforded by 9vHPV vaccine and its safety profile support widespread vaccination as a strategy to drive down the rates of HPV-related cancers.
    Jul 15 Pediatrics abstract



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