US scientists report that they have produced a gene-edited calf with reduced susceptibility to bovine viral diarrhea virus (BVDV), an innovation they say could potentially reduce antimicrobial use in cattle.

In a proof-of-concept paper published yesterday in PNAS Nexus, a team led by scientists with the US Department of Agriculture (USDA) Agricultural Research Service describe how they used CRISPR gene-editing technology to produce a live calf with a six amino acid substitution in the BVDV binding domain of CD46, the main cellular receptor for BVDV. The scientists edited cattle skin cells to develop embryos carrying the altered gene, then transplanted the embryos into surrogate cows.

The calf, named Ginger, was born in July 2021, and after observation for several months was housed for a week with a BVDV-infected dairy calf to determine if she could become infected. Follow-up testing showed Ginger's cells displayed significantly reduced susceptibility to BVDV. The scientists say they will continue to monitor her health.

The most successful version of the future that I can see is one where we don't have to deal with antimicrobial resistance because we just don't use that many antimicrobials.

Although a BVDV vaccine has been available for more than 50 years, the disease remains common in cattle and can cause severe respiratory and intestinal harm to beef and dairy cattle. In addition, when pregnant cows are infected, BVDV can cross the placenta and infect developing calves, resulting in abortion, congenital malformation, or persistently infected cattle who constantly shed the virus and are at risk for secondary bacterial infections.

The authors of paper say that if the approach proves to be viable, it could improve animal welfare and reduce the cattle industry's reliance on antimicrobials.

"The most successful version of the future that I can see is one where we don't have to deal with antimicrobial resistance because we just don't use that many antimicrobials," paper co-author Brian Vander Ley, DVM, PhD, of the University of Nebraska-Lincoln, said in a university press release. "That's better for everyone. That means that we have eliminated the cause of a lot of the antimicrobial use and we've eliminated that expense for livestock producers."

The United States must use lessons learned from the 2022 global mpox outbreak to prepare for future public health emergencies—including the threat of an mpox resurgence this summer, according to a new report from the O'Neill Institute for National and Global Health Law and amfAR, the Foundation for AIDS Research.

The outbreak mainly affected men who have sex with men (MSM) and transgender people—particularly those living with HIV. Public health efforts were hampered by an insufficient supply of the Jynneos mpox vaccine; questions about its safety, effectiveness, and route of administration; and vaccine outreach and delivery disparities among some racial groups.

"Mpox has not been eliminated, and modeling studies suggest that a resurgence is a possibility this summer," the authors said. "We must use lessons learned—most importantly that public health should focus on community-guided partnerships that promote health as opposed to risk-based communications that foster stigma and shame."

Four recommended actions

The organizations recommend four actions to help prevent and manage any future outbreaks:

• Community-led vaccine promotion and education are needed to encourage uptake of both vaccine doses, including vaccination clinics at community spaces and events. "It is also important to educate the community about the heightened risk for severe disease and even death in people with undiagnosed or uncontrolled HIV," the report said.
• Public health messages should build trust and minimize the stigma often associated with mpox. "Mpox responses, building on lessons learned from HIV and critical mpox community advocacy, must reinforce the benefits of promoting sexual health," the authors wrote.
• Mpox testing and vaccination must be integrated within public health programs addressing HIV, other sexually transmitted infections, and hepatitis, and event promoters and influencers should be included in every stage of development and delivery.
• Federal agencies and state and local health departments must foster relationships with organizations that can fund emergency mpox responses. "Outbreaks may recede, but they rarely end," the report said. "Therefore, public health needs the capacity to mount emergency responses that can be scaled-back, but not eliminated, when cases decline."

A small randomized trial in patients with post-COVID syndrome has found that hyperbaric oxygen therapy (HBOT) promotes restoration of the heart's ability to contract properly, according to data presented today at EACVI 2023, a scientific congress of the European Society of Cardiology.

The study enrolled 60 patients in a randomized controlled double-blind trial that measured how and if HBOT helped patients who have mild to moderate long COVID. The therapy involves inhalation of 100% pure oxygen at high pressure, and has been shown to help non-healing wounds, radiation injury, and other types of infection by increasing oxygen delivery to damaged tissues.

All patients had five sessions per week over 8 weeks, for a total of 40 sessions. The HBOT group received 100% oxygen through a mask at a pressure of 2 atmospheres for 90 minutes, with 5-minute air breaks every 20 minutes. The control group breathed 21% oxygen by mask at 1 atmosphere for 90 minutes. Echocardiograms were done before the first session (baseline) and 1 to 3 weeks after the last session.

More research is needed to collect long-term results and determine the optimal number of sessions.

Echocardiography measured the heart's ability to contract and relax based on left ventricular global longitudinal strain (GLS). At baseline, nearly half of study participants (29 of 60; 48%) had reduced GLS. In healthy adults, GLS should be approximately -20%.

In the HBOT group, GLS significantly increased from -17.8% at baseline to -20.2% after the intervention. In the control group the GLS had no significant differences.

"The findings suggest that HBOT promotes recovery of cardiac function in patients with post-COVID syndrome," said Marina Leitman, MD, of the Sackler School of Medicine, Tel Aviv University and Shamir Medical Centre, Be'er Ya'akov, Israel. "More research is needed to collect long-term results and determine the optimal number of sessions for maximum therapeutic effect."

The World Health Organization's (WHO's) mpox emergency committee is meeting today for the fifth time to assess if the outbreak still warrants a public health emergency of international concern (PHEIC).

The WHO declared the emergency in July 2022 following the international spread of the virus. The emergency committee last met in February and typically meets every 3 months, or more often as needed.

In an address to the committee today, Tedros Adhanom Ghebreyesus, PhD, the WHO's director-general, said countries have made steady progress against the disease, which has come with a steep decline in cases. But he added that transmission continues in some communities, such as in the Western Pacific region, and travel-related cases continue to be reported.

Regarding Africa, where the virus is endemic, Tedros said there is no clear trend, and cases continue to be reported in several countries.

The WHO will host a telebriefing tomorrow on global health issues and will likely announce the emergency committee's latest recommendation.