Flu Scan for Jun 23, 2016

News brief

CDC, AstraZeneca weigh in on ACIP FluMist action

In the aftermath of its advisory panel yesterday recommending against inhaled flu vaccine (FluMist) for the upcoming season due to low efficacy, the US Centers for Disease Control and Prevention (CDC) issued a statement on the decision and next steps.

The CDC said its own flu vaccine efficacy data could not find any benefit for FluMist, a live attenuated influenza vaccine (LAIV), in children ages 2 to 17, while injectable flu vaccines, which are not live, had a vaccine efficacy of about 63% for that age-group. It noted that studies elsewhere also found lower effectiveness for LAIV vaccine.

Vaccine performance can vary widely by season, and it is not clear what's behind the poor record for LAIV over the past three seasons, the agency added.

LAIV typically accounts for one third of all flu vaccine given to children, so the CDC said it will be working with manufacturers of injectable vaccine throughout the summer to make sure there is enough to meet the demand. The group said that recommendations of the Advisory Committee on Immunization Practices (ACIP) are reviewed and approved by the CDC director before they become policy.

In a separate statement, AstraZeneca, the maker of the FluMist, said today that the CDC's findings vary from its own findings and those of other groups, which show an overall 46% to 58% effectiveness across all age-groups. The company said it is working with the CDC to better understand the latter's data to ensure that patients can continue to receive LAIV in future flu seasons.

AstraZeneca's US product sales for FluMist totaled $206 million in fiscal year 2015. Based on the ACIP action, the company will take an inventory write-down of $80 million in the second quarter of 2016, said the company statement, adding that distribution and use of the vaccine in other countries is progressing as planned.
Jun 22 CDC statement
Jun 23 AstraZeneca statement
Jun 22 CIDRAP News story "ACIP recommends against inhaled flu vaccine for next season"

H7 avian flu detected in Macau live-poultry market

Health officials in Macau detected an H7 avian flu virus in three birds held at the peninsula's Iao Hon Market, according to a translated report posted today on FluTrackers, an infectious disease message board.

Three stall workers who had close contact with the birds are under observation for 10 days, FluTrackers said. All 9,000 birds at the market's second-floor live-poultry stall have been culled to prevent the spread of infection, and poultry sales have been halted for at least 3 days.

Macau authorities are disinfecting the area and have established a hotline for people who may have been exposed to the infected birds, FluTrackers said.

Macau, an area of China about 50 miles to the west of Hong Kong, imports nearly all its food and live poultry from China's Guangdong province, according to a post yesterday on Avian Flu Diary (AFD). Macau experienced similar detections of an H7 virus last February, leading to market closures and the destruction of 15,000 birds.

Recent H7N9 detections in Hong Kong poultry and in mainland China represent unusual H7 activity, as the viruses are normally inactive during the summer, AFD said.
Jun 23 FluTrackers post
Jun 22 AFD post
Feb 3 CIDRAP News item on previous Macao outbreak

News Scan for Jun 23, 2016

News brief

New MERS case and death reported in Saudi Arabia

The Saudi Ministry of Health (MOH) reported a new MERS-CoV case today, bringing the country's total to 1,400, as well as a death in a previously reported MERS patient.

A 55-year-old Bangladeshi man living in Jeddah tested positive for MERS-CoV (Middle East respiratory syndrome coronavirus). He had primary exposure to the virus, the MOH said, adding that he's currently in stable condition.

The agency also noted that a patient in Najran died from MERS-CoV. The 82-year-old Saudi man had primary exposure to the virus and co-morbidities.

MERS-CoV was first detected in Saudi Arabia in 2012. To date the MOH reports 1,400 confirmed cases, 28 asymptomatic cases, and 595 deaths from the virus.
Jun 23 MOH update

Study: Cognitive problems with West Nile linked to synapse loss

Memory loss experienced by survivors of neuroinvasive West Nile virus (WNV) infection is associated not with cell death, as previously thought, but instead with neuronal synapse destruction in the brain, according to a study today in Nature.

Researchers led by the Washington University School of Medicine found that mice who survived severe WNV disease experienced difficulty in navigating a maze, with minimal improvement in memory after 5 days. Issues with spatial learning were traced to the hippocampus, where an increase in 747 genes that regulate remodeling of the synapses that connect and communicate between neurons was observed.

Neuroinvasive WNV disease appeared to activate microglial cells, which act as macrophages in the brain and spinal cord and which engulfed and destroyed synaptic connections while leaving the neurons themselves intact, the authors said. Synaptic destruction was found in areas of the brain where viral antigen was absent, suggesting the infection's widespread effect on synapses.

Microglia were activated by complement proteins, leading to a 40% decrease in the number of presynaptic terminals 7 days after infection and marking the first time that complement expression in the brain has been observed in severe WNV disease, the authors said.

The study also marks the first time that viral infection has been shown to cause cognitive dysfunction in the absence of neuron death, claimed the researchers. Though WNV infection is rare, 1 in 100 case-patients will develop neuroinvasive disease, and survivors of severe disease are often plagued by memory loss, spatial navigation problems, and irritability.

Synaptic damage in murine survivors similar to that observed in WNV human fatalities presents an opportunity to test new therapies on mice and examine the potential for synapse loss in other diseases that affect cognition, noted the authors.
Jun 23 Nature study