Jun 16, 2010
Vaccine using synthetically weakened flu virus looks good in mouse study
In an effort to create a safer and more effective influenza vaccine, researchers from Stony Brook University (SBU) have developed a new way of creating an attenuated flu virus, using a computer-guided process to introduce hundreds of mutations into its genetic code. Their findings were published online Jun 13 by Nature Biotechnology. The approach is based on the methods the group had used in 2002 to create a synthetic poliovirus, the first artificial virus, and later to create weakened polio viruses, according to a press release today from SBU. The many genetic changes engineered into the synthetic flu virus nearly eliminate the chance of the virus regaining virulence—a problem that can sometimes occur when viruses are attenuated by traditional processes. The mutations don't change the proteins the virus produces, but they reduce protein production, weakening the virus. The group calls the process synthetic attenuated virus engineering (SAVE). The flu vaccine they designed using the SAVE technique was safe and effective when they tested it in mice that were exposed to a lethal flu strain. The new vaccine didn't cause disease in mice unless it was given at a 1,000-fold higher dose than the standard vaccine amount. If applicable in humans, the SAVE technique could be used to make seasonal and pandemic flu vaccines, the group writes. But they note that several issues, including an incomplete knowledge of the molecular mechanism involved in attenuation, will need to be resolved before their approach could be used to make human vaccines.
Jun 13 Nature Biotechnology study
Jun 16 Stony Brook University Medical Center press release
Researchers find longer postexposure window for Marburg vaccine
Researchers have reported further promising results with postexposure testing of an experimental vaccine against Marburg virus, which is often fatal, has no licensed treatment, and is classified as a category A bioterrorism agent. In a report published online today by Emerging Infectious Diseases (EID), investigators say that 5 of 6 monkeys infected with a lethal dose of the virus survived when vaccinated 24 hours after infection, and 2 of 6 survived when treated 48 hours after infection. The authors write that monkeys usually succumb to Marburg virus infections faster than humans and that the postexposure window in humans might be wider than in monkeys. They report that the surviving animals showed moderate to high levels of antibodies against Marburg virus 14 days after infection, seen as further evidence that the vaccine worked as intended. The vaccine uses a weakened vesicular stomatitis virus to carry a component of the Marburg virus. In a previous study in monkeys, the vaccine had provided 100% protection against the virus when given within 30 minutes after exposure. Experts from the National Institutes of Health (NIH) were involved in the study. Anthony Fauci, MD, director of the NIH's National Institute for Allergy and Infectious Diseases, said in a press release that developing safe, effective, and rapidly deployable treatments for filoviruses such as Marburg and Ebola is an important priority for the NIH. "The vaccine used in this study is among several novel approaches to treating filoviruses that show great potential," he said.
Jun 16 National Institutes of Health press release
Jun 16 EID report
MRSA a danger in cystic fibrosis patients
Cystic fibrosis (CF) patients with methicillin-resistant Staphylococcus aureus (MRSA) in their respiratory tract show worse survival than CF patients without the infection, according to a study published in today's Journal of the American Medical Association (JAMA). Included in the study were 19,833 CF patients aged 6 to 45 years who were enrolled from January 1996 through December 2006 and followed through December 2008. Of these, 2,537 died during the study period and 5,759 had MRSA. The mortality rate for patients with MRSA was 27.7 deaths per 1,000 patient-years (95% confidence interval [CI], 25.3 to 30.4), compared with 18.3 (95% CI, 17.5 to 19.1) for those without MRSA. After adjustment for factors related to CF severity, the risk of death was nearly 1.3 times greater in the presence of MRSA. Given the greatly increased prevalence of MRSA in CF patients, aggressive treatment of the infection in these patients and strict infection control precautions in settings that serve them are of crucial importance, say the authors.
Jun 16 JAMA abstract
Vitamin D may help keep viral infections at bay
Serum levels of 25-hydroxyvitamin D correlate with the incidence of viral respiratory tract infections, according to a recent study published by PLoS One. The prospective cohort study measured 25-hydroxyvitamin D concentrations in 195 healthy adults monthly during the fall and winter of 2009-10. Concentrations of 38 nanograms per milliliter or more were associated with a significant (P<0.0001) twofold reduction in acute respiratory tract infections as well as a reduction in the percentage of days ill. Light skin, lean body mass, and vitamin D supplementation were found to correlate with higher levels of 25-hydroxyvitamin D.
PLoS One study
Group aims pro-immunization message at fathers
In a pitch timed to coincide with Father's Day, a group of health professionals launched an immunization campaign yesterday titled "Real Guys Immunize," which explains how dads can protect their families by receiving influenza and other recommended vaccines. Two of the central themes are promoting the idea of herd immunity and dispelling vaccine myths on an "iherd" frequently-asked-questions page. The group's Web site also includes a resource page, a site where guests can share stories about fathers who put a high priority on vaccination, and links to a "Real Guys Immunize" Facebook page and Twitter feed.
Real Guys Immunize Web site