Moderna's RSV vaccine shown to provide strong protection against serious cases in adults 50 and older
News briefToday at 4:30 p.m.
Stephanie Soucheray, MA
Topics
Respiratory Syncytial Virus (RSV)
A single dose of Moderna’s mResvia RSV vaccine was 60.3% protective against documented respiratory syncytial virus (RSV) infections, 60.2% against RSV-associated emergency department or urgent care encounters, and 81.8% against RSV-associated hospitalizations in a population of older US veterans, according to a recent study in JAMA Network Open.
The study used a target trial framework to assess veterans 50 years and older receiving care in the Veterans Health Administration from October 1, 2025, to January 31, 2026. Eligible vaccine recipients were matched with up to four unvaccinated people in four monthly, nested, sequential trials, the authors said, and followed up for 24 weeks.
In all, a total of 74,926 vaccinated veterans were matched to 286,425 unique controls.
Efficacy declined with age
While the vaccine was effective across all ages, estimated effectiveness against documented infections decreased with increasing age, from 82.9% in the 50- to 59-year age-group, to 28.6% in the 80-year or older age group, the authors said.“Our findings also show similar estimated effectiveness against RSV illness conferred by mRNA-1345 as observed with protein-based RSV vaccines evaluated in earlier seasons,” the authors wrote. “Further follow-up is needed to assess the durability of mRNA-1345 protection over multiple seasons, whereas comparative effectiveness studies can inform relative protection of different RSV vaccine products.”
The vaccine was approved by the US Food and Drug Administration (FDA) in May 2024 for adults 60 and older. The FDA expanded the approval in June 2025 to also include adults 18 to 59 who are at increased risk of lower respiratory tract disease caused by RSV.
Kenya begins Ebola-free countdown as DR Congo tops 11,000 cases
News briefToday at 3:29 p.m.
Stephanie Soucheray, MA
Topics
Ebola
Kenyan officials said a 42-day countdown has begun after the last Ebola patient was discharged from medical care. Now two transmission cycles must pass before the country can say it is free of Ebola, after nine people were infected when a man traveled from the Democratic Republic of Congo (DRC) to Kenya in early October.
In addition to the index patient, who died on October 5, four health workers and four family members of the index patient were infected. The nation recorded one death besides the index patient, in a 65-year-old relative the BBC has identified as the index patient’s mother.
“Today with the discharge of the last patient we can confirm and tell the world that seven patients have recovered—and all contacts have completed their follow-up monitoring,” said Kenya’s Cabinet Secretary of Health Aden Duale, MBA, in a media briefing.
Africa CDC head says Kenya’s response ‘encouraging’
Kenya is the third African nation outside of the DRC to see an Ebola case from the Bundibugyo strain causing the current outbreak. Nigeria has had one case, and Uganda is now Ebola-free after 20 cases were recorded earlier this summer.“The discharge of the last patient and the release of the remaining contacts from quarantine reflect the strength of Kenya's public health response, from early detection and contact tracing to clinical care and community engagement,” said Africa Centres for Disease Control and Prevention Director-General Jean Kaseya, MD, MPH, on X. “This is an encouraging moment for Kenya and for Africa. We must sustain surveillance and vigilance until the outbreak is officially declared over.”
The most recent Ebola case counts in the DRC show 11,042 infections and 5,387 deaths. The virus has been detected in eight of 26 provinces.
Clinicians should avoid Lyme disease PCR in favor of serologic testing, study authors say
News briefToday at 11:39 a.m.
Mary Van Beusekom, MS
Topics
Lyme Disease
Tick-borne Disease
Polymerase chain reaction (PCR) testing for Lyme disease produces low positivity, only nominally informs clinical decision making, and represents substantial healthcare costs in endemic areas, per a new study in Open Forum Infectious Diseases.
The study authors, from the State University of New York Upstate Medical University, say the findings favor reliance on serologic testing for the tick-borne disease and support initiatives to limit unnecessary PCR use.
Caused by the spirochete bacterium Borrelia burgdorferi carried by black-legged (deer) ticks, Lyme disease is the most common vector-borne illness in the United States. Diagnostic guidelines recommend serologic testing over PCR because it is more sensitive. But both tests have limitations, the researchers note.
The single-center study of all B burgdorferi PCR results was performed in Upstate New York from January 2024 through June 2026.
Potential diagnostic stewardship opportunity
During the study period, 885 B burgdorferi PCR tests were performed. Half of the specimens were cerebrospinal fluid (CSF; 50.1%), followed by synovial fluid (35.6%) and blood (14.4%). Overall positivity was 1.9%.By specimen, positivity was 5.4% for synovial fluid and zero for CSF and blood. The PCR tests cost $401,790 total ($201,122, $143,010, and $57,658 for CSF, synovial fluid, and blood specimens, respectively).
Of the 17 positive B burgdorferi PCRs, 64.7% didn’t affect treatment, because antibiotics had already been started based positive serologic results and clinical presentation. The median time from collection to PCR result was 7.2 days due to the need to send samples to a lab.
Thus, six positive PCRs (36.3%) helped guide clinical decision making, but five of those patients had not undergone serologic testing at the same time as PCR. Of the 17 positive PCRs, an infectious disease consult was made in only three cases.
“These findings highlight an important diagnostic stewardship opportunity to reduce unnecessary PCR utilization while providing clinician education on promoting adherence to evidence-based diagnostic recommendations for Lyme disease,” the researchers wrote.
It should be noted that the senior author on the study reported a potential conflict of interest related to DiaSorin, maker of a Lyme disease serologic test.
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