NEWS SCAN: H5N1 deaths, novel flu vaccine, flu shots and Medicaid, H1N1 immunity, Salmonella sleuthing, Mexican vaccine plant

Oct 18, 2010

Indonesia reports two H5N1 deaths
Indonesia's health ministry recently announced two new H5N1 avian influenza deaths, both in adults, the World Health Organization (WHO) said today. The first is a 35-year-old man from West Jakarta who got sick in mid August, was hospitalized Aug 20, and died on Aug 27. Investigators found that sudden chicken deaths had occurred around the man's house a week before he became ill. The other victim is a 40-year-old woman from Kota Depok, West Java, who got sick Sep 9, was hospitalized Sep 12, and died on Sep 17. The initial probe into the source of her infection suggests she may have been exposed to the virus at a live bird market. Kota Depok is part of an urban area that surrounds Jakarta. Indonesia's H5N1 total now stands at 170 cases and 141 deaths, both of which are the highest in the world.
Oct 18 WHO statement

Study: Flu vaccine with novel target may provide broad protection
Scientists say they have developed an influenza vaccine that, by targeting the stalk rather than the head of the virus's hemagglutinin protein, could be effective against multiple flu subtypes. Writing in the Proceedings of the National Academy of Sciences (PNAS), the scientists say previous studies revealed that some antibodies with activity against multiple flu subtypes target the hemagglutinin stalk. (Existing vaccines target the head of hemagglutinin, the molecule that enables flu viruses to bind to host cells.) The new vaccine consists of amino acids 76 to 130 of hemagglutinin subunit 2 (HA2) (a region chosen because it is the binding site of an antibody called nAb 12D1), plus a carrier protein called KLH. The authors tested the vaccine by giving mice two doses 3 weeks apart. Subsequently, serum samples from the mice showed activity against hemagglutinins from the 1968 H3N2 virus, the 2009 H1N1 virus, and H2, H5, and H7 viruses. In addition, when exposed, the vaccinated mice enjoyed significant protection against H3, H1, and H5 viruses, compared with control mice. The authors, with Peter Palese of Mount Sinai School of Medicine in New York City as senior author, write that their results "provide proof of concept for an HA2-based influenza vaccine that could diminish the threat of pandemic influenza disease and generally reduce the significance of influenza viruses as human pathogens."
Oct 18 PNAS abstract

Study: Better Medicaid rates could raise kids' flu vaccinations
Increasing the amount that Medicaid reimburses physicians for administering the flu vaccine might be one way to raise rates in poor children, researchers from the University of Rochester Medical Center (URMC) reported today in Pediatrics. The group looked at state-to-state vaccination data in children ages 6 to 23 months from the National Immunization Survey over three consecutive flu seasons, starting with the 2005-06. Federal officials launched a flu vaccine recommendation for this age-group in 2004. Then the study group compared the vaccination data with Medicaid reimbursement patterns in each state. The federal Vaccines for Children Program covers the cost of the vaccine for eligible children but not the cost of administration, which varies widely by state, averaging from $8 to $9. However, researchers reported that the actual administration cost is $20. Using modeling methods, they projected that each extra reimbursement dollar could raise vaccination rates by 0.6 to 0.9 percentage points. They concluded that raising Medicaid reimbursement from the $8 median to $18 could raise vaccination rates in poor children by six to nine percentage points.
Oct 18 URMC press release
Oct 18 Pediatrics abstract

About half of British Columbians have protection against novel H1N1
A Canadian Medical Association Journal (CMAJ) study released today suggested that about half of British Columbia residents have protective levels of antibodies to pandemic 2009 H1N1 influenza, with about 70% of those younger than 20 or older than 80 having seroprotection. Researchers measured antibody protection against pandemic H1N1 in 1,127 serum samples from patients in British Columbia's Lower Mainland. One hundred samples per 10-year age-group were chosen based on convenience sampling, except for 224 samples in the under-10 category and 103 in the 10-to-19 category. Seroprotection, defined as a hemagglutination inhibition titer of 40 or higher, was lowest among people 70 to 79 years old (21%) and highest among those 90 and older (88%). It was 44% among those aged 20 to 49 and 30% among those 50 to 79. By comparison, less than 10% of samples collected from all age-groups in this population before the pandemic showed comparable seroprotection.
Oct 18 CMAJ abstract

Deciding when to investigate matching Salmonella isolates
Foodborne disease researchers from Minnesota say their analysis of 8 years' worth of outbreak investigations suggests some criteria for predicting whether a cluster of genetically matching Salmonella isolates is likely to lead to the identification of a confirmed outbreak. A team led by Dr. Kirk Smith of the Minnesota Department of Health (MDH) reviewed investigations of Salmonella isolates that had matching pulsed-field gel electrophoresis (PFGE) patterns. From 2001 through 2007, 43 (13%) of 344 such clusters led to the identification of outbreaks, according to their report in Emerging Infectious Diseases (EID). They found that PFGE clusters of at least four cases were more likely to be solved than smaller clusters. Further, they determined that clusters in which the first three isolates were received by the MDH within 7 days were more likely to be solved than when it took more than 14 days. "These results establish a benchmark for surveillance of Salmonella infections, and may provide a basis for investigating clusters of Salmonella cases for public health agencies with limited resources," the report states.
November EID report

Sanofi opens flu vaccine plant in Mexico
Sanofi Pasteur has opened a $140 million facility to make influenza vaccines in Mexico City, the Associated Press (AP) reported Oct 16. Mexican President Felipe Calderon said the plant will improve Mexico's preparedness for flu pandemics. Sanofi Pasteur said the facility will make 30 million doses of antigen annually and that a government-run manufacturer will finish the production steps and distribute the vaccines, according to the story. The plant was built outside Mexico City and inaugurated Oct 15.
Oct 16 AP story

This week's top reads