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.

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."

Three African countries—Chad, the Democratic Republic of the Congo (DRC), and Nigeria—reported a total of seven new cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, according to an update yesterday from the Global Polio Eradication Initiative (GPEI).

Chad noted 3 cVDPV2 cases, 1 each in the nation's capital, N'Djamena, and Ouaddai province (with onset of paralysis in November 2024), and in Logone Oriental province (with onset of paralysis in February 2025), bringing the total number of cVDPV2 cases in 2024 to 39, and for 2025 to 3.

The DRC confirmed 1 cVDPV2 case, in Mai-Ndombe province, and it is included in the country's 2024 total, which has now grown to 15.

Nigeria has 3 new cases, all with paralysis onset in January, bringing the country's cVDPV2 total this year to 6. They are in Borno and Jigawa states in the north. The country saw 98 such cases in 2024.

Expert groups convene

The GPEI said the Strategic Advisory Group of Experts on immunization (SAGE) is meeting this week at World Health Organization headquarters in Geneva, following last week's meeting of the IHR Emergency Committee on Polio Eradication (IHR EC).  

Among other vaccine topics, SAGE is expected to review the global poliovirus epidemiology and current status of the sunsetting of the bivalent (two-strain) oral polio vaccine. The IHR EC reviewed the latest detections of wild poliovirus type 1 in Afghanistan and Pakistan and cVDPV circulation worldwide. Reports from both meetings will be published in the coming weeks, the GPEI said.