In an update on the JN.1 variant late last week, the US Centers for Disease Control and Prevention (CDC) said the variant—steadily expanding its dominance—may be intensifying the spread of COVID-19 this winter. In the January 5 update, the CDC said COVID activity is high, but infections are causing less severe disease than earlier in the pandemic.

The variant, part of the BA.2.86 lineage, accounts for about 62% of variants, up from 44% 2 weeks ago. Also, the CDC said it is seeing an increase in JN.1 prevalence in international travelers and in wastewater in all US regions. JN.1 is dominant in Europe and is rising sharply in Asia.

Low vaccine uptake

Though test positivity and wastewater levels are moderately higher than last year at this time, emergency department visits are trending a bit lower over the same period.

The uncoupling of infection levels and illness severity is related to greater immune protection from previous disease, vaccination, or both, the CDC said, adding that more than 97% of people have antibodies against SARS-CoV-2. "This immune protection can fade over time but tends to last longer for preventing severe disease than for preventing infections," the agency said.

Long COVID remains an important health threat, and the CDC warned that not enough Americans have received the updated vaccine, with uptake at bout 8% in children and 19% in adults. For seniors, 38% have gotten the latest vaccine, "which is concerning given that they are at higher risk of hospitalization from COVID-19."

A survey of national tuberculosis (TB) program staff members projects consistent global growth in the use of shorter, all-oral drug regimens for drug-resistant TB (DR-TB), but national efforts to ensure the new treatments are accessible to eligible patients are needed, researchers reported late last week in PLOS One.

To project uptake of the World Health Organization–recommended BPaL/M (bedaquiline, pretomanid, and linezolid, with or without moxifloxacin) regimens for DR-TB, a team led by researchers with the TB Alliance conducted semi-structured interviews with national TB program staff members and experts in the 13 countries that accounted for 69% of DR-TB incidence in 2021. The researchers used the interviews, which aimed to gather intelligence on established plans and targets for DR-TB regimens from 2023 to 2026, to make projections on global uptake of the regimens, which have shortened DR-TB treatment from nearly 2 years to 6 months.

Increased uptake of shorter regimens expected

Overall, the study projected that BPaL/M regimens will be used in most DR-TB patients by 2024 and reach 78% of DR-TB patients by 2026, with BPaLM reaching 126,792 patients and BPaL reaching 43,716 patients by 2026. In addition, 13,119 patients will be treated with a 9- to 11-month all-oral bedaquiline-based regimen. Respondents in the interviews indicated the all-oral nature of the BPaL/M regimens, short duration, reduced cost, and reported high efficacy is expected to result in higher uptake.

But the study authors add that national TB programs and the global health community will need to prepare for this scale-up by procuring the drugs for these regimens, updating national guidelines, educating and training clinicians and health workers, engaging patients, and expanding drug-susceptibility testing (DST).

"This study will be informative for global health stakeholders, including donors, policy makers and manufacturers, by supporting planning and budgeting for DR-TB interventions," they wrote. "Above all, national efforts to scale-up DST and implement new treatments will be essential for ensuring that these medicines are accessible to all eligible patients in the coming years.

• In an ongoing investigation into a recent measles cluster, the Philadelphia Department of Public Health (PDPH) has now confirmed five cases and has reported three suspected infections. In a January 5 update, the agency said three patients remain hospitalized. The initial patient was hospitalized in early December, which resulted in three confirmed cases in patients who weren't immune to the virus. One of the patients attended daycare on December 20 and 21, exposing children and staff. In a previous update, PDPH said the patient's caregivers had disregarded quarantine and exclusion instructions. Two children at the daycare tested positive, both of whom were hospitalized. Three other potential cases have been reported in kids from the daycare. Health officials continue to track potentially exposed people and are offering free measles, mumps, and rubella (MMR) vaccination at city health centers.
• South Sudan's health ministry recently reported a yellow fever outbreak, with one case confirmed so far. The patient is an 18-year-old man from Yambio County in Western Equatoria state in the southwest, according to a December 24 statement. His symptoms began on December 21, and after healthcare providers determined that his illness met the case definition for yellow fever, they isolated the man and collected a blood sample. Testing at the country's national lab and at the Uganda Virus Research Institute confirmed yellow fever. The South Sudan health ministry has activated the emergency operations center to coordinate the response and is conducting a field investigation with a team of experts from partner organizations. With World Health Organization support, the health ministry has applied for yellow fever vaccine doses from the global stockpile for campaigns in the affected region.
• A bombing today by militants in northwestern Pakistan near the Afghanistan border has killed five police officers who were in a truck on their way to guard polio vaccinators working on a campaign in a tribal area, the Straits Times reported today. The Pakistan Taliban has reportedly claimed responsibility for the bombing, part of a series of attacks ahead of Pakistan's February 8 national election. The attack also wounded 20 other officers. Pakistan is one of a few countries where wild poliovirus type 1 (WPV1) is still endemic, but extremist groups have targeted polio vaccination efforts due to suspicions that the immunizers are spies, and that the vaccine could make Muslims infertile.