A new modeling study by researchers with the World Health Organization (WHO) estimates that more than 5 million antimicrobial resistance (AMR)-related deaths could occur in the WHO's Western Pacific Region over the next decade.

The study, conducted by researchers with the WHO Collaborating Centre for Infectious Disease Epidemiology and Control at the University of Hong Kong, used data from eight countries and one area in the region on the health impact (morbidity and mortality) and economic cost (gross domestic product [GDP] loss due to decreased work productivity) of infections caused by antibiotic-resistant bacteria compared with antibiotic-sensitive bacteria from 2010 through 2019.

The researchers focused on seven bacterial infections of importance for human health: methicillin-resistant Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Streptococcus pneumoniae.

Because many countries in the region have limited AMR data, the researchers then extrapolated the data to other countries in the region based on the nearest GDP per capita and estimated the health impact and economic cost of AMR in each of the region's 37 countries and areas from 2020 to 2030.

The impacts are not distributed equally, and AMR is an especially serious threat for some of the poorest people and most marginalized populations in the Region.

The model estimated a worst-case scenario of 450,000 AMR-related deaths in 2020 and a projected cumulative total of 5.2 million AMR-related deaths across the region over the decade. The estimated regional AMR mortality rate is similar to regional mortality rates for kidney diseases, diabetes mellitus, liver cirrhosis, and breast cancer.

Patients with AMR infections were projected to spend 172 million extra days in the hospital. The AMR-related health cost was projected to reach US$ 148 billion.

"Despite the data limitations, the study provides compelling evidence for the potential health and economic costs of AMR in the Western Pacific Region," the researchers wrote. "The impacts are not distributed equally, and AMR is an especially serious threat for some of the poorest people and most marginalized populations in the Region."

The authors add that more and better-quality data are needed to understand the trajectory of AMR in the region and reduce the uncertainty around its impacts.

A single dose of the VLA1553 chikungunya virus vaccine candidate triggered neutralizing antibody production in 98.9% of recipients 28 days later, finds a phase 3 randomized, controlled trial published yesterday in The Lancet.

Chikungunya is a mosquito-borne virus that causes periodic outbreaks of an illness featuring severe joint and muscle pain that can lead to chronic rheumatic (inflammatory) disease.

A team led by vaccine manufacturer Valneva in Vienna evaluated immune responses to VLA1553 in 362 adults (266 vaccine recipients and 96 placebo recipients) at 43 US trial sites from September 17, 2020, to April 10, 2021, and a larger safety cohort.

Safety profile similar to other vaccines

One dose of VLA1553 generated chikungunya virus neutralizing antibodies in 263 (98.9%) of 266 recipients (95% confidence interval [CI], 96.7% to 99.8%) 28 days later, regardless of age.

In the safety analysis involving 3,082 VLA1553 recipients and 1,033 placebo recipients, serious adverse events occurred in 1.5% and 0.8%, respectively, for a similar safety profile to other licensed vaccines. Two serious adverse events were considered related to VLA1553, but both recipients recovered fully.

In a Lancet news release, lead study author Martina Schneider, PhD, of Valneva, said VLA1553 could be the first chikungunya vaccine available for people living in areas where the virus is endemic, travelers to these areas, and regions at risk for an outbreak.

"Our promising results showed good persistence of antibody levels after vaccination, which is important considering that chikungunya outbreaks may recur suddenly," she said. "As age is a risk factor for severity and mortality of chikungunya disease, the strong immune response observed in older participants might be particularly beneficial."

In a related commentary, Kathryn Stephenson, MD, MPH, of Beth Israel Deaconess Medical Center, said that, despite the need for studies on VLA1553 in adolescents and on real-world effectiveness, the vaccine will help chikungunya pandemic preparedness efforts. "Chikungunya virus and other arboviral infections continue to be global threats, spurred on by the expansion of mosquito habitats because of climate change and globalisation of trade and travel," she wrote.

Our promising results showed good persistence of antibody levels after vaccination, which is important considering that chikungunya outbreaks may recur suddenly.

China has reported another H9N2 avian flu case, which involves a 7-month-old boy from Jiangxi province, Hong Kong's Centre for Health Protection said today in one of its regular avian influenza updates.

The boy's symptoms began on May 1. His illness marks the mainland's third H9N2 case in the past 6 months. The two earlier cases involved young children from Jiangxi and the Hunan provinces.

H9N2 is known to circulate in poultry in some Asian countries. Infections in humans are typically mild and are more likely to be reported in children, especially those who have contact with poultry or poultry environments.

• In a document posted ahead of the June 15 vaccine advisory group meeting, Food and Drug Administration scientists said current evidence suggests that a monovalent (single-strain) XBB lineage COVID vaccine is warranted for a fall vaccine campaign. They said XBB.1.16 could be dominant by the fall, with XBB.2.3 and other related lineages increasing, as well. They noted that XBB.1.16, XBB.1.5, and XBB.2.3 spike proteins are similar and could be candidates to include in the next version of the vaccine.
• The Centers for Disease Control and Prevention in a recent update reported a fourth fungal meningitis death of a US patient exposed to epidural anesthesia at certain Mexican cosmetic surgery clinics. Health officials are investigating 179 people who were exposed, including 14 suspected cases (people who have symptoms) and 14 probable cases (people who have suggestive spinal tap results). So far tests have confirmed the fungus, reported to be Fusarium solani, in four patients.
• The US Department of Agriculture's Animal and Plant Health Inspection Service reported 5 more H5N1 avian influenza detections in mammals, bringing the total to 196. All 5 were in California, 2 two detections in fishers. The other 3 were in raccoons.