NEWS SCAN: New Zealand's 2010 flu wave, flu vaccine in UK, H5N1 prime-boost, H1N1 in China, public health funds, cholera update

Feb 10, 2011

New Zealand officials find vaccine helped ease 2010 flu impact
Surveillance data on the impact of pandemic 2009 H1N1 influenza in New Zealand show a similar chronological progression of the disease between 2009 and 2010 but a lower impact of the disease in 2010. New Zealand officials who issued the report today in Eurosurveillance said vaccination appears to have contributed to the decreased impact. Although demographic characteristics of the 2010 wave were similar to those in 2009—with highest rates in children under 5 years and in indigenous Maori and Pacific populations—community cases, hospitalization rates, and intensive care unit (ICU) cases were all lower in 2010. Compared with 2009 rates, consultation rates in 2010 for flu-like illness were 72%, hospitalization rates 72%, and ICU admissions 87.4%. In addition, although 2010 saw fewer confirmed deaths (15), the rate of 8.5 per 100,000 cases was similar to the 2009 level of 9.0. The researchers estimated that pre-second-wave immunity to 2009 H1N1 flu, based on exposure and vaccination, ranged from 25.2% in those aged 20 to 39 to 66.6% in people 60 and older. The authors conclude, "Immunisation appears to have contributed to the reduced impact of the pandemic in 2010, particularly for those aged 60 years and older."
Feb 10 Eurosurveillance report

UK experts share early flu vaccine effectiveness findings
UK health officials today released an interim report on the effectiveness of last season's monovalent flu vaccine and this season's trivalent vaccine against the region's flu strains so far, most of which has been the 2009 H1N1 virus, with some influenza B. They found that 2009 H1N1 protection was best in people who were vaccinated both seasons and that coverage seemed to wane in those who only received last season's monovalent vaccine. Their study used data from four sentinel surveillance systems in England, Wales, and Scotland and is based on information from 4.554 people who were swabbed for flu-like illness. The study included 1,251 case-patients who tested positive for 2009 H1N1 flu and 2,229 controls, whose results were negative. Adjusted vaccine effectiveness against the 2009 H1N1 virus was 34% (95% confidence interval [CI]: -10% to 60%) for those who received only the monovalent vaccine last year, 46% (CI 7% to 69%) in those who received only the trivalent vaccine this season, and 63% (CI 37% to 78%) in those vaccinated both seasons. Against influenza B and H3N2, the adjusted vaccine effectiveness was 50% (CI 17% to 70%). The researchers said their findings were consistent with previous vaccine effectiveness findings for seasonal flu vaccines during the prepandemic years when circulating strains are a good match with the vaccine. The findings suggest a dose-response relationship to 2009 H1N1 protection, which the investigators said reinforces the importance of yearly vaccination for recommended groups.
Feb 10 Eurosurveillance report

Study: Stockpiled H5N1 vaccine useful for prime-boost strategy
An H5N1 vaccine in the US Strategic National Stockpile could be used as a powerful tool in a pandemic setting, even though the 2004 strain of the virus in it wouldn't match current or future circulating H5N1 strains, researchers report in the Journal of Infectious Diseases. The United States currently has 20 million doses of a vaccine against the 2004 Vietnam strain of H5N1. Researchers tested different prime-boost strategies using the stockpiled vaccine alone or in combination with an experimental H5N1 vaccine that contains the Indonesian strain, the most common circulating strain. The randomized, prospective multicenter trial of 491 healthy adults also measured the effect of different time intervals between the two doses. Each dose of the H5N1 vaccine contained 90 micrograms of antigen. Immune responses using the different vaccine combinations were modest, with two doses needed to protect against a flu virus with a novel hemagglutinin antigen. A 180-day interval between the first and second dose gave the best protection but might not be an option in a quickly developing pandemic, the group reported.  They concluded that giving the stockpiled Vietnam H5N1 vaccine first primed the immune system for to heighten the response to the newer vaccine. Robert Bleshe, MD, lead author of the study and director of Saint Louis University's Center for Vaccine Development, said in a EurekAlert press release yesterday, "The most surprising thing we discovered was the value of time. It's incredible how much stronger response you get at six months. There's something going on there that we know nothing about and is a very interesting area for future research."
Feb 9 EurekAlert press release
Mar J Infect Dis abstract
Oct 31, 2007, CIDRAP News story "The pandemic vaccine puzzle part 5: what role for prepandemic vaccination?"

H1N1 takes over as China's dominant flu strain
As China enters the peak of its flu season, the 2009 H1N1 virus has edged out H3N2 as the dominant strain, the country's health ministry said today, according to Xinhua, China's state news agency. Shu Yuelong, head of China's National Influenza Center, said 2009 H1N1 evolved as the dominant strain over the last 2 months, and though officials expect more severe cases to occur, the virus is not likely to have the same impact it did in 2009. The country has reported 129 severe 2009 H1N1 cases since late 2010, including 20 deaths since the start of 2011. He said confirmed flu infections and outpatient and emergency department visits for flu-like illness are all below last season's high levels. Vaccination against the 2009 H1N1 virus also appears to be effective, he added.
Feb 10 Xinhua story

HHS announces $750 million investment in public health
The US Department of Health and Human Services (HHS) announced yesterday a $750 million investment in prevention and public health for 2011, including $137 million to help shore up public health infrastructure. The allocation, part of the Prevention and Public Health Fund established by the 2010 Affordable Care Act, "is designed to expand and sustain the necessary capacity to prevent disease, detect it early, manage conditions before they become severe, and provide states and communities the resources they need to promote healthy living," according to an HHS release. Last year the agency distributed $500 million from the fund. This year's spending includes $298 million for community prevention measures; $182 million for clinical prevention, which includes immunizations; $137 million for state and local public health infrastructure, including funding for disease outbreak detection and response; and $133 million on research and tracking the impact of the Affordable Care Act and other evidence-based public health measures. In a separate release today, the nonprofit Trust for America's Health (TFAH) praised the funding, saying, "Preventing disease and injury is the most effective, common-sense way to improve health in the United States." The fund will provide $16.5 billion over 10 years for bolstering local and state public health efforts.
Feb 9 HHS press release
Feb 9 TFAH release

PAHO investigates more AFP cases in Haiti
Pan American Health Organization (PAHO) officials in Haiti are investigating more potential cases of acute flaccid paralysis (AFP) in people recovering from cholera and are asking health partners to increase vigilance for the condition, the agency said yesterday in an update. Polio has been ruled out in the first four patients with AFP from Northwest department, but PAHO new suspected cases are from another department. Meanwhile, the number of new cholera cases appears to be stabilizing or even declining, and health officials have been able to turn their attention to post-earthquake activity such as rebuilding the country's National Blood Service and a nursing school in Port-au-Prince. So far the number of confirmed cholera cases in Haiti is 216,938, including 4,120 deaths. PAHO also said mortality rates are decreasing.
Feb 9 PAHO update
In other cholera developments, scientists have described a key advance toward a better, faster test to detect the cholera toxin in sick patients, the American Chemical Society (ACS) reported yesterday. The new method uses nanoparticles that are prepared with iron oxide and coated with dextran sugar. Cholera toxin in water, blood, or other fluid binds to the nanoparticles, which can be detected by instruments. A study describing the findings appeared in the ACS journal Bioconjugate Chemistry.
Feb 9 ACS press release
Bioconjug Chem abstract

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