CDC recommends preventive RSV shot for infants

News brief

The Centers for Disease Control and Prevention (CDC) said yesterday that it is recommending immunization with nirsevimab to protect all infants under 8 months of age and some older infants from severe illness caused by respiratory syncytial virus (RSV).

Marketed under the trade name Beyfortus, nirsevimab is a long-acting monoclonal antibody developed by AstraZeneca. It was approved last month by the US Food and Drug Administration for newborns and infants entering their first RSV season, and in children up to 24 months of age who are entering their second RSV season and are vulnerable to severe RSV disease.

New CDC director Mandy Cohen, MD, MPH, signed off on the recommendation following a unanimous vote by the CDC's Advisory Committee on Immunization Practices (ACIP). The injection will be added to the recommended childhood immunization schedule.

Leading cause of infant hospitalization

While most infants and young children with RSV experience mild, cold-like symptoms, an estimated 58,000 to 80,000 children under the age of 5, mainly infants, are hospitalized each year for RSV infection, which can lead to lower respiratory tract diseases such as pneumonia and bronchiolitis. An estimated 100 to 300 children under 5 die from complications caused by the virus annually, according to the CDC.

Infant with RSV in hospital — graphixchon / iStock

RSV typically starts circulating in the fall and peaks in the winter in most parts of the United States. It's transmitted through close contact with someone who's infected.

"This new RSV immunization provides parents with a powerful tool to protect their children against the threat of RSV,” Dr. Cohen said in a CDC press release. "RSV is the leading cause of hospitalizations for infants and older babies at higher risk and today we have taken an important step to make this life saving product available."

Nirsevimab is expected to be available this fall. The CDC said it will provide additional guidance and healthcare provider educational material in the coming months.

CDC reports 2023’s first two US human infections with swine flu

News brief

Chris Dall, MA

The first two US human infections with swine flu viruses in 2023 were reported this week in Michigan, according to an update today by the Centers for Disease Control and Prevention (CDC).

The CDC said the two infections occurred in people who attended different agricultural fairs in Michigan and had contact with pigs. The infections were caused by two different types of flu virus variants—likely influenza A(H3)v and influenza A(H1N2)v—that are usually associated with contact with pigs.

The Michigan Department of Health and Human Services reported the presumptive positive influenza A(H3)v infection on July 26 in a person who had attended a fair that took place from July 7 to July 16. An investigation found that the patient had been exposed to pigs 10 days prior to illness onset, was treated with flu antivirals, and recovered.

Exposure at ag fairs

The influenza A(H1N2)v infection was reported on July 31 (and later confirmed at the CDC) in a person who had been exposed to pigs during a fair held from July 23 to July 29. That individual was also treated with flu antivirals and is recovering. Neither patient was hospitalized.

Agricultural fairs can increase the risk that flu viruses will spread among pigs and between pigs and people. The CDC recommends not eating or drinking while in pig areas, avoiding contact with pigs that appear to be sick, and washing hands before and after contact with pigs.

Ten new polio cases reported in DRC

News brief

Chris Dall, MA

The Democratic Republic of the Congo (DRC) has reported 10 new cases of circulating vaccine-derived poliovirus type 1 (cVDPV1), according to the latest update from the Global Polio Eradication Initiative (GPEI).

The 10 cases, 9 from Tanganyika province and 1 from Haut Katanga province, bring the total number of cVDPV1 cases reported in the country this year to 46. DRC also reported 4 new cases involving circulating vaccine-derived poliovirus type 2 (cVDPV2), 2 each from Haut Lomami and Lualaba provinces, bringing the 2023 total to 61 cases.

Nigeria also reported a new cVDPV2 case this week, from Kebbi province, and has now reported 19 this year. Countries reporting cVDPV2-positive environmental samples include Nigeria (1), Algeria (2), and Yemen (5).

Pakistan reported one wild poliovirus type 1 (WPV1)-positive environmental sample.

GPEI also published the sixth report of the Transition Independent Monitoring Board, which evaluates the progress and challenges of transferring the responsibility of polio immunization and response efforts to national governments. The report includes a series of recommendations to strengthen the process at the global, regional, and country level.