The US Food and Drug Administration (FDA) yesterday announced the strains it recommends manufacturers include in seasonal flu vaccines for the 2025-26 flu season, and they mirror recommendations announced by the World Health Organization (WHO) last month. 

The agency's vaccine advisory committee typically makes the recommendation in early February following an open session that includes a public hearing. With the change in presidential administration, however, the FDA shelved its usual deliberations on the topic by its Vaccines and Related Biologics Advisory Committee (VRBPAC), which typically includes input from FDA scientists, as well as those from the Centers for Disease Control and Prevention (CDC) and the Department of Defense.

Input narrowed to federal agencies

The FDA posted the presentations from the interagency group that recommended the strains in its announcement. Unlike previous years, there wasn't input from any vaccine company representatives or those from the WHO Collaborating Center for Surveillance Epidemiology and Control of Influenza.

The FDA recommendations are the same as for last month's WHO advisory committee recommendation for the 2025-26 Northern Hemisphere vaccines, which switch to a different H3N2 influenza A strain for the egg- and cell-based vaccines.

"With today's action, the FDA does not anticipate any impact on timing or availability of vaccines for the American public," the FDA said, adding that it expects an adequate and diverse supply of trivalent (three-strain) vaccines for the next US flu season.

The results of a small randomized controlled trial in Italy suggest that probiotics may be helpful in treatment of children with upper respiratory tract infections (URTIs), Italian researchers reported today in JAMA Network Open.

Conducted in the pediatric emergency unit of a hospital in Milan, the trial involved 128 children (ages 28 days to 4 years) who presented with a fever and URTI at some point from November 19, 2021, to June 20, 2023. The children were randomized 1:1 to receive a daily single dose of a commercially available probiotic mixture containing Bifidobacterium breve, Bifidobacterium lactis, and Lactobacillus rhamnosus or a daily dose of placebo for 14 days. The primary outcome was fever duration.

Of the 128 children enrolled (54% male; mean age, 2.5 years), 65 received the probiotic mixture and 63 received placebo. Thirty-three patients were receiving antibiotics at enrollment.

Fever duration reduced by 2 days

The median fever duration was 2 days shorter in the probiotic group than in the placebo group (3 days vs 5 days; adjusted risk ratio, 0.64; 95% confidence interval [CI], 0.51 to 0.80). Reported adverse events included diarrhea (4 cases), constipation (12), and abdominal pain (5). The distribution of adverse events did not differ significantly between the probiotic and placebo groups.

“The probiotic mixture under investigation could be an effective adjuvant for shortening fever duration in children with URTIs,” the study authors concluded.

The authors say the findings align with growing evidence on the immunomodulatory effects of probiotics, including studies showing that probiotics can enhance humoral immunity, can increase the production of antibodies, and demonstrate activity against prevalent respiratory viruses. 

"These mechanisms may partly explain the significant reduction in fever duration observed in this trial," they wrote.

In its latest biannual update on Middle East respiratory syndrome (MERS) in Saudi Arabia yesterday, the World Health Organization (WHO) reported four new cases since September 6, 2024, two of them fatal. 

MERS is an often-severe respiratory infection caused by the MERS coronavirus (MERS-CoV), leading to symptoms such as fever, shortness of breath, and cough. It spreads among camels and can infect humans, usually through direct or indirect contact with camels. The virus rarely spreads from person to person.

Of the four infected men aged 27 to 78 years, all of whom had underlying medical conditions, one was exposed to the virus in a hospital, and one was indirectly exposed to camels and their raw (unpasteurized) milk. None were healthcare workers. The cases were reported in Saudi Arabia's Hail (2), Riyadh (1), and Eastern (1) provinces. 

No vaccine or specific treatment is currently available, although several MERS-CoV–specific vaccines and therapeutics are in development.

The Saudi Arabian Ministry of Health followed up on the men's close contacts, finding no other secondary infections. The last case was reported on February 4, 2025.

"The notification of these four cases does not alter the overall risk assessment, which remains moderate at both the global and regional levels," the WHO said. "The reporting of these cases shows that the virus continues to pose a threat in countries where it is circulating in dromedary camels, particularly those in the Middle East."

Case-fatality 36% since 2012

Since MERS was first detected in humans in Saudi Arabia in 2012, 2,618 people from 27 countries in all six WHO regions have been infected, with a case-fatality rate of 36%. The vast majority of cases, 84%, have been identified in Saudi Arabia. No MERS infections have been reported outside the Middle East since 2019.

"No vaccine or specific treatment is currently available, although several MERS-CoV–specific vaccines and therapeutics are in development," the WHO wrote. "Treatment remains supportive, focusing on managing symptoms based on the severity of the illness."