Experts weigh in on the future of Ebola vaccines
Exceptional Ebola surveillance and swift responses to outbreaks will be the key to taking advantage of the availability of Ebola vaccines, say three experts who offered their thoughts on the future use of such vaccines in a new article from the World Health Organization (WHO).
Marie-Pierre Preziosi, MD, PhD, of the Initiative for Vaccine Research at the WHO said that once a vaccine is licensed, "We should be prepared to move swiftly and with clear operating procedures and agreement between countries worldwide."
Ebola vaccine use is initially envisioned as part of a response to an outbreak, she said. The vaccine should first be given to high-risk persons, mainly healthcare workers and other frontline responders such as cleaning people and those involved in burying the dead. The next recipients would be direct contacts of those infected (ie, ring vaccination), then contacts of contacts, and in the case of a rapidly spreading outbreak, everyone in the area surrounding a case cluster.
Dr. Dennis Marke of Sierra Leone's ministry of health and sanitation wrote that although it is valuable to have the promising vesicular stomatitis virus–Ebola virus (VSV-EBOV) vaccine in the pipeline, "The vaccine will only be useful for cutting short an outbreak if we identify any cases that occur promptly and then swing into action. Above all, we must stay alert and do superb surveillance."
Marke said the finding that the virus can persist in semen for up to a year will influence vaccination of sexual partners of Ebola survivors, and the fact that Ebola vaccines in trials have initially made some recipients ill may affect the agents' popular acceptance. He expressed hope that participants in vaccine trials will "serve as champions for the new vaccine."
Jane Seward, MBBS, MPH, of the US Centers for Disease Control and Prevention (CDC), a senior adviser to the Sierra Leone vaccine trials, focused on the reassurance the public should feel now that the VSV-EBOV vaccine, while not yet licensed, can be used in an emergency.
She observed, however, that bringing a vaccine to market typically takes many years, so "we still have quite a way to go." Of particular interest as testing proceeds will be whether VSV-EBOV can provide long-term benefits in addition to the demonstrated short-term ones, as well as how other vaccines now in clinical trials will fare.
Apr 15 WHO story
Ten more children's flu deaths reported as season fades
Influenza activity continued its slow fade across the United States last week, but the season left 10 more children's deaths in its wake, along with signs of a late-season surge in influenza B viruses, according to the CDC.
The children's deaths reported last week occurred in late March and early April, and six of them were attributed to type B, which often claims a larger share of cases late in the flu season. Two deaths were linked to A/H1N1 viruses, one was tied to an H3, and one was due to a type A virus that was not subtyped, the CDC said in its weekly update. The 10 deaths raised the season total to 50.
Among all flu viruses that were tested last week, 58.2% were type A and 41.8% were type B, the CDC reported. The share of B isolates was up from the previous week's 34.5% and well above the whole-season mark of 27.3%.
Most other flu markers last week pointed to a continuing decline. New Jersey was the only state still reporting high influenza-like illness (ILI) activity, down from two states a week earlier. Hawaii and Puerto Rico reported moderate activity, compared with seven states in that category the week before.
Flu cases were said to be still geographically widespread in 18 states and Puerto Rico, but that was a drop from 25 states and Puerto Rico the previous week.
In the CDC's outpatient surveillance network, the share of clinic visits prompted by ILI dropped to the national baseline of 2.1%, down from 2.4% the week before. And the proportion of respiratory samples that tested positive for flu sank to 14.0%, from 16.2% the previous week.
One measure that increased a bit last week was the share of deaths attributed to pneumonia and influenza in the 122 Cities Mortality Reporting system, at 7.5%, staying above the epidemic threshold of 7.1%. The previous week it was 7.4%.
As for flu-related hospitalizations, the cumulative incidence for the season reached 26.6 per 100,000 people last week, up from 24.4 a week earlier. The rate among seniors was 69.6 per 100,000.
Apr 15 CDC FluView update
GAO renews its call for strategic oversight of US biodefense efforts
In a report released yesterday, the US Government Accountability Office (GAO) reiterated its previous appeals to designate one person or group and frame an integrated strategy to coordinate the US government's many programs and efforts dedicated to protecting the nation against biological threats.
"The biodefense enterprise is fragmented and does not have strategic oversight to promote efficiency and accountability," the GAO said.
The agency, which serves as Congress's investigative arm, noted that in 2011 it reported that the government had more than two dozen presidentially appointed officials and many agencies with biodefense responsibilities, but no person or entity with responsibility to oversee the whole biodefense enterprise.
In December 2014, National Security Council (NSC) officials told the GAO that two NSC directorates work together as the focal point for federal biodefense efforts, the report says. "This is an important step in promoting a comprehensive and coordinated approach to biodefense," it adds, "but strategic leadership issues persist."
The GAO also said it reported in 2011 that the government lacked a broad, integrated national biodefense strategy to guide the identification of risks, assess resources, and set spending priorities. As of February of this year, such a strategy was still lacking, the agency said.
Further, the GAO said it recommended in 2010 that the Homeland Security Council establish a focal point to lead the development of a national biosurveillance strategy, but the recommendation has not been fully implemented.
In addition, the GAO since 2009 has made recommendations to address challenges with specific biodefense capabilities: state and local public health, animal health surveillance, the National Biosurveillance Integration Center, and the Biowatch Program, according to the report. Not all of those recommendations have been implemented, it says.
Apr 14 GAO report
WHO advisers recommend dengue vaccine for high-burden countries
At its meeting that ended yesterday, the WHO Strategic Advisory Group of Experts (SAGE) on immunizations recommended that countries consider using Sanofi's Dengvaxia vaccine, the first of its kind, only where the disease is highly endemic, defined as about 70% or higher seroprevalence in the targeted age-group.
The live attenuated vaccine has now been licensed in several dengue-endemic countries in Asia and Latin America.
Countries should carefully assess introducing the vaccine depending on local priorities, have systems in place for vaccination tracking, and not use the vaccine in children age 9 and younger, because of a risk of severe disease in young children, as reflected on the label.
The group considered evidence from two large phase 3 studies in children and modeling analyses to gauge the possible public health impact in seven different settings, according to a WHO statement.
In other meeting developments, the group heard updates on global progress toward the changeover from oral polio vaccine type 2 (OPV) to inactivated polio vaccine (IPV) in routine immunization strategies. They raised concerns about global IPV shortages, which are expected to persist into 2017 and 2018, and urged countries to weigh the benefits and drawbacks of different dosing schedules.
Regarding wider vaccine shortages, SAGE heard concerns about sometimes critical disruptions in immunization programs. They said an overall view of the situation is missing and is needed to help prevent and manage shortages. A draft resolution on the topic will be presented to the World Health Assembly in May, and the group recommended that the WHO establish an exchange forum to help improve communication on threats to the vaccine supply between manufacturers and countries.
Apr 15 WHO SAGE statement
ECDC offers guidance for battling carbapenem-resistant infections
The European Centre for Disease Prevention and Control (ECDC) on Apr 8 released strategies to combat the spread of carbapenem-resistant Enterobacteriaceae (CRE) in healthcare settings and community food production.
Since 2013, 13 European countries have reported the spread of enteric bacteria resistant to carbapenem, a last-line antibiotic for treating multi-drug resistant (MDR) infections. A mean of 7.3% of Klebsiella pneumoniae isolates in Europe were carbapanem-resistant in 2014, but rates varied widely by country, with the highest rates observed in Greece, Italy, and Romania, the ECDC said.
A 2011-12 survey of European hospitals found that 18 countries had evidence of healthcare-associated CRE transmission. Severe infections are associated with a 30%-75% mortality rate due to lack of prompt confirmation and treatment. To combat hospital spread, the ECDC recommends quick laboratory confirmation when a CRE case is suspected, rigorous isolation and infection control for CRE patients in hospitals, and development of antimicrobial stewardship programs that provide treatment options for MDR cases.
The ECDC also recommends instituting hospital screening procedures for patients who are likely to carry CRE or who have been hospitalized in a region where CRE is prevalent, including the Indian subcontinent, the United States, Greece, Italy, Turkey, and North Africa.
Addressing community spread of CRE will require greater surveillance of antimicrobial resistance in food-producing animals and enhanced biosecurity on farms, the ECDC said. CRE infections will likely continue to rise unless a global effort is made to develop new antibiotics, regulate inappropriate antimicrobial use, and improve water and sanitation systems.
Apr 8 ECDC rapid risk assessment
Estimate of duodenoscope infections higher than previously thought
A recent US congressional investigation found that infections from contaminated duodenoscopes have likely been underestimated, prompting the introduction of new federal legislation, according to a story today by Chad Terhune in the Los Angeles Times.
A Feb 15 report from the US Food and Drug Administration (FDA) to the House Committee on Oversight and Government Reform found that as many as 404 infections and 44 exposures, representing 300 to 350 patients, were related to contaminated duodenoscopes. The scopes were used during endoscopic retrograde cholangiopancreatography (ERCP) diagnostic procedures at 30 American and 11 overseas medical facilities between Jan 1, 2010, and Oct 31, 2015, the story said.
A US Senate report in January had estimated that only 250 scope-related infections occurred at 25 US and European hospitals between 2012 and 2015.
The new estimates and recent scope-related outbreaks, many of which were related to duodenoscopes manufactured by Olympus Corp. of Tokyo, Japan, prompted the introduction today of legislation designed to tighten medical device reporting requirements, the report said. If passed, the Device Act will require manufacturers to notify the FDA about product design changes, new cleaning requirements, and safety problems that occur outside the United States. A second bill requires scientific validation of device cleaning and decontamination procedures.
More than 650,000 ERCP procedures are performed nationally each year. Additional oversight will provide hospitals with evidence-based information to help prevent future outbreaks, according to the Times.
Apr 15 Los Angeles Times story
Jan 15 CIDRAP News item about duodenoscope outbreaks
Study suggests malaria drug resistance is not transmittable
A new study in Science suggests that although malarial parasites resistant to the treatment atovaquone thrive in human hosts, genetic characteristics do not allow the resistance characteristics to transfer from human to mosquito or human to human.
An international group of researchers led by investigators from the University of Melbourne discovered that although Plasmodium berghei malaria parasites resistant to atovaquone persist in mice, in Anopheles mosquitoes the mutations disable female parasites too much for them to reproduce.
The researchers could not directly study the transference capabilities in humans, but they were able to look at rodent models and P berghei as well as mosquito crossbreeding with the human-specific Plasmodium falciparum, according to the study. Their findings suggest that the mitochondrial cytochrome b complex, the source of atovaquone resistance, also results in effective female sterility and therefore the inability to transfer the resistance gene.
The authors wrote, "From 44 separate transmission attempts involving 750 mosquito bites, atovaquone resistance transmission was only observed once, and this mutant was unable to transmit further despite seven attempts."
Atovaquone was commonly used for pregnant women and children, according to a University of Melbourne press release, but because of observed parasitic resistance, prescriptions for the drug declined. Learning about this "genetic trap" could cause the use of atovaquone to increase, the authors say.
Apr 14 Science study
Apr 14 press release
