The main markers the Centers for Disease Control and Prevention (CDC) uses to track COVID activity showed small rises today from very low levels, including wastewater SARS-CoV-2 detections, which rose from the minimal to low level over the past week.

Most of the rise in wastewater detections was due to a steady rise in the western region, with a very slight increase in the southern region. 

The CDC considers wastewater levels an early indicator. The agency also reported slight rises in two other early indicators, test positivity and emergency department visits for COVID. Test positivity is currently highest in Arizona, California, Hawaii, and Nevada.

Upward trend comes with variant shifts

The small rise comes amid rising proportions of JN.1 offshoots. Last week in its variant proportion update, the CDC said two of them—KP.2 and KP.3—made up 41.2% of sequenced samples.  The two variants both contain the FLiRT (F for L at position 456 and R for T at position 346) mutation, which may give them the capacity to evade earlier immunity from illness or vaccination.

On June 5, the Food and Drug Administration Vaccines and Related Biological Products Advisory Committee (VRBPAC) will meet to discuss what COVID strain or strains to include in 2024-25 COVID vaccines. 

Current vaccines target the XBB.1.5 variant, but JN.1 has become the dominant strain. The World Health Organization COVID vaccine advisory group recently met and recommended a switch to a monovalent (single-strain) vaccine containing the JN.1 antigen. Some countries such as Singapore have reported rising cases, partly due to increasing proportions of JN.1 variants.

Moderna today announced that the US Food and Drug Administration (FDA) has approved its mRNA vaccine against respiratory syncytial virus (RSV) for people ages 60 and older, bringing the number of approved RSV vaccines to three.

The vaccine, called mRESVIA, was granted approval under an FDA breakthrough therapy designation. The vaccine is the second Moderna mRNA vaccine to be cleared by the FDA.

In a press release, the company said the vaccine is the only RSV vaccine available in single-dose prefilled syringes, making it easier to administer.

Efficacy 84% after 3 months

The approval was based on findings from a phase 3 study that included more than 37,000 adults and spanned 22 countries. After 3.7 months of follow-up, researchers found an efficacy of 83.7% against lower respiratory tract disease from RSV. Further analysis found a vaccine efficacy of 78.7%, and a longer-term analysis found protection at the 8.6-month mark. 

No serious safety concerns were noted, and the most common adverse events were injection-site pain, fatigue, and myalgia.

Moderna said the vaccine will be available for the 2024-25 respiratory virus season.

The World Organization of Animal Health (WOAH) said yesterday that it has revised its international standards to strengthen efforts to control antimicrobial resistance (AMR).

The revisions to the international standards on AMR, which provide a framework for surveillance of antimicrobial use and AMR in animals, were agreed to during WOAH's 91st General Session in Paris. They cover three major areas: the environment, companion animals, and WOAH's list of antimicrobial agents of veterinary importance. 

Creating a pathway to responsible use

WOAH officials say the changes to the environmental section of the international standards reflect an increasingly interconnected world and the need for a One Health approach when dealing with AMR. 

"In fact, considering the potential environmental impact of antimicrobial use in animals is of critical importance," the agency said in a news release. "Either qualitative or quantitative, an environmental risk assessment should be conducted by the pharmaceutical industry when submitting applications for regulatory approval for veterinary medicinal products containing antimicrobial agents."

Regarding companion animals, WOAH said closer interactions between humans and companion animals worldwide, and the growing evidence of bidirectional transfer of resistant pathogens between pets and their owners, called for a revision of the standards to raise awareness of the need to promote responsible antimicrobial use in companion animals and increase awareness around risks and good practices among pet owners.

Finally, WOAH updated its list of antimicrobial agents of veterinary importance to align it with the World Health Organization's updated list of important antimicrobials for human medicine, adding phosphonic acid derivatives to the list of antimicrobials that should not be used in animals.

"Together, this year's changes to the standards on AMR are meant to create a pathway for a responsible antimicrobial use in different animal health contexts and settings," the agency said.

Among tested household members (HHM) of Ebola patients in Uganda, 38% also contracted the disease, with adults having direct contact with the patient at higher risk and those with access to a handwashing facility at lower risk, finds a study posted yesterday in BMC Infectious Diseases.

Uganda National Institute of Public Health researchers retrospectively studied disease transmission in households with an Ebola patient in January 2023, after a 2022 outbreak caused by the Sudan virus (SUDV), mainly affecting the Mubende and Kassanda districts. 

The team tested 44 of the 76 HHM of the index patient (58%) less than 2 weeks after their last exposure to the patient and administered a risk-factor questionnaire to the index patient or another adult HHM.

Case households were defined as those housing a symptomatic index patient for at least 24 hours and one or more secondary patients with symptom onset less than 2 weeks after their last contact with the index patient. Control households included an index patient and other HHM but no secondary infections.

Outbreaks of Ebola, which can cause severe bleeding, organ failure, and death, usually occur after contact with the body fluids or meat of infected non-human primates or fruit bats. Person-to-person spread occurs through direct contact with the fluids or tissues of an infected, symptomatic person.

Providing patient care, sharing bed raise risk

Twenty-nine of the 44 HHM tested for SUDV (38%) were also infected. Risk factors included being an adult (adjusted risk ratio [aRR], 1.9) and having direct or indirect interaction with the index patient (aRR, 3.2). 

Risk assessments during contact tracing may provide evidence to justify closer monitoring of some HHM.

Direct contact, especially providing nursing care for or sleeping in the same space as the index patient, increased the odds of infection. Having access to a handwashing facility lowered the risk (aRR, 0.52).

"Risk assessments during contact tracing may provide evidence to justify closer monitoring of some HHM," the study authors concluded. "Health messaging should highlight the risk of sharing sleeping spaces and providing nursing care for persons with Ebola disease symptoms and emphasize hand hygiene to aid early case identification and reduce transmission."

• Watmind USA, a medical diagnostics company based in Jackson, Mississippi, today announced that the US Food and Drug Administration has granted emergency use authorization (EUA) for its over-the-counter rapid test for COVID-19, influenza A, and influenza B. The test kit is marketed under the SpeedySwab brand and is indicated for use in people ages 2 years and older. It was developed in partnership with the National Institutes of Health Rapid Acceleration of Diagnostics (RADx) Independent Test Assessment Program.
• The Chicago Department of Public Health said yesterday that a measles outbreak centered at a migrant shelter is over, now that two incubation periods (42 days) have passed with no new cases. The outbreak began in March and was the city's first in 5 years. It totaled 64 cases over the following weeks, 57 of them linked to the migrant shelter. As part of the response, health workers administered more than 30,000 doses of measles, mumps, and rubella (MMR) vaccine.
• Five counties reported new polio cases this week, all involving vaccine-derived types, the Global Polio Eradication Initiative (GPEI) said in its latest weekly update. Angola reported its second circulating vaccine-derived poliovirus type 2 (cVDPV2) case of the year, and Chad, the Democratic Republic of the Congo (DRC), Niger, and Nigeria also reported more cases involving the strain. Also, the DRC reported two more cases of circulating vaccine-derived poliovirus type 1 (cVDPV1).