NEWS SCAN: Vaccine safety, antivirals and severe H1N1, Salmonella tuna cases, UK pertussis spike

Jul 27, 2012

WHO advisors reaffirm vaccine safety
A World Health Organization (WHO) advisory group reaffirmed the safety of influenza vaccines during pregnancy, thimerosal as a vaccine preservative, and aluminum used as an adjuvant, according to a report in the WHO's Weekly Epidemiological Record today. The Global Advisory Committee on Vaccine Safety (GACVS), at a meeting last month, reported that data continue to underscore the safety of flu vaccination in pregnant women. Specifically citing US data as well as findings from the 2009 H1N1 pandemic, the group wrote, "GACVS concludes that the data remain very reassuring for the use of vaccines during pregnancy, with no evidence of adverse fetal outcomes identified." The GACVS, which had affirmed the safety of thimerosal ("thiomersal" in the report) in vaccines in 2008, also assessed data published since that time, including a risk assessment by the US Food and Drug Administration and 28 studies that addressed post-vaccination mercury blood levels. It found strong support for thimerosal safety, and called three ecological studies that suggested a link between thimerosal and neurodevelopmental disorders "fraught with methodological flaws." In fact, the GACVS said, "No additional studies of the safety of thiomersal in vaccines are warranted," adding, "Thiomersal allows millions of people worldwide to have access to life-saving vaccines." Finally, the GACVS examined two studies purporting to show an association between aluminum adjuvants (immune-boosting additives) in vaccines and autism. It found the studies "seriously flawed."
Jul 27 Wkly Epidemiol Rec issue (scroll to page 281)

Study: Antiviral treatment led to higher survival among severe H1N1 cases
Neuraminidase inhibitors (NIs) like oseltamivir (Tamiflu) increased survival rates in patients admitted to intensive care units (ICU) during the 2009 H1N1 pandemic and appeared to have benefit even when given 5 days after symptom onset, according to a study in Clinical Infectious Diseases. Researchers studied 1,859 California ICU patients, 1,676 (90%) of whom received NIs and 183 (10%) of whom did not. Of the 1,676 patients receiving NIs, 1,260 (75%) survived, compared with 107 (58%) of the 183 patients not receiving HIs. They also found a trend toward improved survival among those treated earliest, but treatment even 5 days after symptom onset was associated with improved survival.
Jul 26 Clin Infect Dis abstract

Salmonellosis cases from raw tuna climb to 425 as CDC declares outbreak over
In its final report on the outbreak, the Centers for Disease Control and Prevention (CDC) said yesterday that raw scrape tuna contaminated with Salmonella sickened 425 people in 28 states, an increase of 35 cases and one state since the previous update on Jun 21. Two strains have caused illness, with 410 cases attributed to Salmonella Bareilly and 15 to Salmonella Nchanga. New Hampshire was the latest affected state. Investigation by federal, state, and local officials determined that a frozen raw yellowfin tuna product known as Nakaochi Scrape and produced by Moon Marine USA Corp. of Cupertino, Calif., was the source of illnesses. The CDC first announced the outbreak on Apr 4, and Moon Marine recalled 58,828 pounds of the product on Apr 13. States with the most cases were New York (68), Pennsylvania (37), Virginia (34), Illinois (30), Wisconsin (25), and Georgia (22).
Jul 26 CDC statement

England reports spike in pertussis cases
Pertussis cases in England and Wales continuing to climb this year, with 2,466 cases so far, more than double the total for all of 2011, the country's Health Protection Agency (HPA) said today in a statement. Infections have been reported across all of England's regions, including clusters in schools and healthcare settings. The disease runs in cycles, and in 2008 when the last peak year occurred, 421 cases had been reported by this point in the year, the HPA said. Babies younger than 3 months are among the case-patients, and so far five infant deaths have been attributed to the disease. Mary Ramsay, MD, the head of immunization at the HPA, said in the statement that health officials are reviewing options for curbing the outbreak, including booster doses for teens and vaccination of pregnant women. England's announcement seems to echo a US spike in pertussis activity. On Jul 19 the US Centers for Disease Control and Prevention warned that the country may be headed for its highest number of pertussis cases in decades, with an unusual spike in 13- to 14-year-olds that it said could herald waning vaccine immunity. The HPA statement did not mention a gap in vaccine immunity as a factor in the UK outbreak, but it did show that 1,851 of the 2,466 cases were in patients age 15 and older, with 323—the second highest number—in those ages 10 to 14.
Jul 27 HPA statement
Jul 19 CIDRAP News story "CDC: Pertussis numbers suggest vaccine protection gap"

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