Flu Scan for May 09, 2016

News brief

Genetic findings tie poor flu vaccine results in 2014-15 to drifted H3N2 strain

The performance of the seasonal influenza vaccine was exceptionally weak in the 2014-15 season, a failure that was attributed largely to its low effectiveness against a drifted strain of A/H3N2 virus that became dominant. Now, US researchers have reported clear genetic evidence that the drifted strain undermined vaccine effectiveness (VE).

Using a novel genetic sequencing tool, the researchers found that the vaccine showed no effectiveness against the drifted H3N2 strain but did provide some defense against an H3N2 strain more like the one used in the vaccine. They presented their findings May 6 in the Journal of Infectious Diseases.

Researchers in the US Flu Vaccine Effectiveness Network used a pyrosequencing assay to identify genetic groups in H3N2 viruses isolated from patients, according to the report. VE was estimated by the test-negative design, in which patients who have a flu-like illness are tested for flu and their vaccination status is determined.

Among 9,710 patients at the network sites, 1,838 (19%) tested positive for H3N2 infections, the report says. Genetic sequencing of the hemagglutinin protein of 1,397 viruses revealed that 81% were the drifted strain, called 3C.2a. VE against this strain was estimated at 1% (95% confidence interval [CI], -14% to 14%), whereas as VE against the more vaccine-like strain (3C.3b) was 44% (95% CI, 16% to 63%).

Overall flu VE in 2014-15 was estimated at 23%, with much better performance against H1N1 and influenza B viruses than against H3N2, according to previous reports. A recent meta-analysis revealed that VE against H3N2 viruses over 11 recent seasons was only 33%, compared with 54% for B strains and 61% for 2009 H1N1.

In an accompanying commentary, Michael Schotsaert, PhD, and Adolfo Garcia-Sastre, PhD, of the Icahn School of Medicine at Mt. Sinai in New York City suggest that new technologies like pyrosequencing may permit faster detection of significant flu virus mutations and quicker responses to them.

“If interim VE is low, or if a poor VE is expected based on observed genetic variation, one could theoretically decide more quickly on future adjustments in vaccination strategies and on clinical preparedness for influenza disease in target groups at specific regions,” they wrote.

They add that the challenges that viral antigenic drift poses for existing flu vaccines underline the need for improved vaccines that would provide protection against both circulating and drifted strains.
May 6 J Infect Dis abstract, full text
May 6 J Infect Dis commentary
Apr 7 CIDRAP News story on flu VE against H3N2 over 11 seasons
Apr 5 CIDRAP News story on 2014-15 flu VE in Canada

WHO details 2 recent H5N6 avian flu cases in China

Two human cases of H5N6 avian flu that were reported in China to the World Health Organization (WHO) from Apr 21 to 26 involved contact with live poultry before symptoms appeared, the WHO said in an update late last week.

The agency added that the situation, which brought the global total of cases to 12, "does not change the overall public health risk from avian influenza A (H5N6) viruses."

Both cases were reported previously by local authorities, who reported yet another case on May 3 that has yet to be confirmed by the WHO. The first case noted by the WHO on May 6 involved a 35-year-old man in the Shennongjia forest region of Hubei province (in central China). He is in critical condition, the WHO said.

The second case is in an 11-year-old girl in Zhuzhou City, 300 miles south-southeast of Shennongjia in Hunan province. She is in stable condition. No contacts have tested positive for the virus in either case.

To prevent further cases, the Chinese government is raising awareness about disease identification and prevention strategies as well as increasing surveillance and resources around research and treatment, according to the update. The WHO asks other countries to continue influenza surveillance and severe acute respiratory infections. China has reported the only human H5N6 cases, but other nations in the region have detected the virus in birds.

The WHO advises travelers going to countries with known avian flu outbreaks to practice good hygiene and avoid potential contact with contaminated poultry or feces by staying away from places like poultry farms and live-animal markets.
May 6 WHO update

News Scan for May 09, 2016

News brief

Takeda gets $38 million Gates grant to boost polio vaccine supply

Takeda Pharmaceutical Company today announced a $38 million grant from the Bill and Melinda Gates Foundation, part of a partnership to develop a safe, effective, and affordable Sabin-strain inactivated polio vaccine (IPV) for developing countries.

Japan-based Takeda said in a statement that it will use the funding to supply at least 50 million IPV doses per year to more than 70 developing nations. The company's IPV vaccine was originally licensed from the Japan Polio Research Institute, and vaccine funded by the grant will be made at Takeda's facility in Hikari, Japan.

The announcement comes amid a massive, orchestrated switchover to a new bivalent oral polio vaccine (OPV) that began on Apr 17, prompted by the eradication of type 2 polio. Following type 1 and type 3 eradication, routine OPV immunization will be stopped and replaced with IPV, which doesn't carry the rare risk of vaccine-derived polio seen with OPV. Several countries are in the process of introducing IPV into their national immunization programs, which has led to steep demand and global vaccine shortages.

Chris Elias, president of global development at the Gates Foundation, said in the statement, "In 2016, the world is closer than ever to eradicating polio. To eradicate polio we need to ensure every last child is protected from this disease—this partnership will help ensure that the world has enough vaccine to get the job done and maintain a polio-free world."
May 9 Takeda press release

In other polio developments, a technical assessment of Ukraine's polio outbreak response has concluded that transmission has been interrupted, the World Health Organization (WHO) regional office for Europe said in a May 6 statement. The agency said, though, that it is still concerned about gaps in immunization and surveillance that put Ukraine at high risk for new outbreaks.

Last September, two cases were detected in the southwestern part of the country, which prompted three rounds of supplemental immunization.
May 6 WHO European regional office statement

NYC simulates bioterrorism attack in subways

Today the Department of Homeland Security (DHS) will use harmless airflow tests to see how a bioterror attack could travel and affect the New York subway system, New York magazine reported yesterday.

The study will last a week, and unlike the 2013 New York Police Department's simulated gas attack study, it will include a particle test to look at how potential bioterror agents such as Bacillus anthracis (the bacterium that causes anthrax) or ricin could travel.

The researchers will use sugar-based particulates that have a diameter no bigger than one tenth of a human hair. Machines will release them at busy stations, and other machines, filters, and patches on platforms, subway cars, and researchers will collect them to track their spread.

The technology DNATrax, a 2013 R&D 100 award winner from the Lawrence Livermore National Laboratory, allows researchers to identify which collected particles are theirs by essentially giving each particle a unique barcode, according to the story.

The DHS, Metropolitan Transportation Authority, and others report that the test is completely harmless, according to the article.
May 8 New York article