Dec 7, 2010
Experts explore possible paths to a universal flu vaccine
Recent advances in influenza immunology suggest that "the goal of a universal cross-protective influenza vaccine is feasible," two leading experts at the National Institute of Allergy and Infectious Diseases (NIAID) write in a commentary in Nature Medicine. Like the immune system itself, existing vaccines target the head of the flu virus's hemagglutinin (HA) protein, which often mutates, requiring reformulation of the flu vaccine each year, they note. They focus on the possibility of developing vaccines that target a much more stable region on the stem of HA flu virus's hemagglutinin protein. Recent studies have shown that in mice and ferrets it is possible to stimulate the production of antibodies that target this region of the HA stem and thereby provide protection against a variety of flu strains. The authors, Gary J. Nabel and Anthony S. Fauci, say one approach is to develop a vaccine designed to be effective against all 16 types of HA by targeting this conserved region of the HA stem. Because the feasibility of this approach is not yet clear, a second pathway would be to focus first on the three flu subtypes most likely to sicken humans—H1, H2, and H3—and aim to develop a composite vaccine that would work against all variants within those groups. "In essence, it may be possible for a new generation of vaccines to do even better than natural infection in eliciting a safe and effective immune response against the ever-present threat of influenza," Nabel and Fauci conclude.
Nature Medicine commentary Full text
Dec 6 NIAID news release
Study: Flu vaccine supply glitches contribute to uptake inequities
Problems with flu vaccine supply can worsen gaps in flu vaccination among older people, African-Americans, and Hispanics, according to a study from researchers at the University of Rochester Medical Center (URMC) in Rochester, N.Y. They used Medicare data and surveys of Medicare recipients to explore disparities in flu vaccine coverage, known to be higher in whites, according to a URMC press release. The findings are slated to appear in an upcoming issue of American Journal of Preventive Medicine. To gauge fluctuations in vaccine uptake, they followed recipients through two concurrent flu seasons sometime between 2000 and 2005. The 2000-2001 and 2004-2005 seasons were marked by severe shortages, while the 2001-2002 and 2003-2004 seasons saw moderate supply problems. In years that saw vaccine shortages, gaps between whites and other groups rose 2% to 7%, but the disparities narrowed 2% to 11% when supplies were adequate. The authors said a number of factors could be driving some of the disparities, such as more pronounced vaccine shortages in underserved communities and language barriers. They recommended that populations with greater risks of flu complications be prioritized for vaccine supply and that outreach efforts to these groups be improved.
Dec 6 URMC press release
CDC and partners pitch flu vaccine in open letter to Americans
The US Centers for Disease Control and Prevention (CDC) yesterday issued an open letter signed by 44 health organizations urging Americans to get vaccinated against seasonal flu. This week marks National Influenza Vaccination Week, designed to boost vaccination rates in advance of the holiday season and into 2011. In the letter, the CDC and its partners emphasized that the 2009 H1N1 pandemic showed how unpredictable flu can be and that the vaccine is recommended for nearly everyone except those younger than 6 months. They reminded Americans that last season's monovalent vaccine may not protect against the viruses circulating this season and that certain groups have a higher risk of flu complications, including older people, young children, people with underlying health conditions, and pregnant and postpartum women. In other developments, the CDC said yesterday that 163 doses of flu vaccine have been distributed as of Nov 26. It said vaccine manufacturers project they will make 160 million to 165 million doses for the US market this flu season, a record high.
Dec 6 CDC flu vaccine supply update
Antibiotic-treated, untreated pigs often have Campylobacter, drug resistance
Researchers found that swine raised by conventional versus antimicrobial-free (ABF) methods had similar levels of Campylobacter contamination on the farm and that antibiotic resistance was common in both groups. They studied 34 farm-slaughter pair cohorts raised in Ohio, Michigan, Wisconsin, and Iowa, collecting 838 fecal and 1,173 carcass samples. Campylobacter levels did not vary significantly based on production system, with a 58.9% prevalence in conventional and a 53.8% prevalence in ABF systems. The prevalence at the slaughterhouse varied by production stage: 19.4% at pre-evisceration, 25.3% at post-evisceration, and 3.2% at post-chill. Comparisons between conventional and ABF samples were not made at slaughter. Resistance among Campylobacter-positive samples was found to be common to tetracycline (64.5%), erythromycin (47.9%), and nalidixic acid (23.5%). Campylobacter isolates from conventional production were more likely to be erythromycin-resistant than were those from ABF systems, with an odds ratio of 3.2. However, ciprofloxacin resistance was more common in ABF isolates: 3.7% to 1.2%. Erythromycin and ciprofloxacin are commonly used to treat human Campylobacter infections.
Dec 6 Food Pathog Dis study