respiratory syncytial virus

noun

plural respiratory syncytial viruses

1

: a pneumovirus (species Human orthopneumovirus of the genus Orthopneumovirus) that usually causes mild infections of the upper respiratory tract and lungs, that is spread through contact with respiratory droplets, and that is characterized especially by fever, cough, congestion, and runny nose but may progress to bronchiolitis and pneumonia especially in infants, the elderly, and immunocompromised individuals

Respiratory viruses like COVID-19, influenza and respiratory syncytial virus often spread and peak during winter, when people travel for the holidays and spend more time indoors and breathing the same air.

—Jessica Rendall

Respiratory syncytial virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms in most people. … Infections typically go away on their own in a week or two.

—Ema Sasic

Note: Respiratory syncytial virus was initially identified in 1956 and was formerly classified as a paramyxovirus.

called also RSV

2

: the illness caused by respiratory syncytial virus

Symptoms of respiratory syncytial virus are comparable to those of a common cold and COVID-19. Symptoms include runny nose, fever, coughing, sneezing, decreased appetite and wheezing.

—Tyler Brown

An unseasonably early spike in respiratory syncytial virus cases among young children is pushing some hospitals to capacity.

—Vanessa Romo

called also RSV

Examples of respiratory syncytial virus in a Sentence

Recent Examples on the Web

Coinciding with Wednesday’s hearing was a CDC vaccine advisory committee meeting to discuss a recommendation for a vaccine for respiratory syncytial virus (RSV). —Erika Edwards, NBC news, 25 June 2025

The United States could soon have another tool in the fight against respiratory syncytial virus, an illness that’s the No. 1 cause of hospitalization in infants. —Jen Christensen, CNN Money, 10 June 2025

Kennedy has also stalled other overdue recommendations from the panel for respiratory syncytial virus, or RSV, vaccines and meningococcal vaccines. —Paula Cohen, CBS News, 27 May 2025

Other whole-virus vaccines, including the first ones developed to fight respiratory syncytial virus or RSV, have caused problems such as immune enhancement, where exposure to the virus after vaccination makes the infection more dangerous, not less. —Meg Tirrell, CNN Money, 1 May 2025

Word History

First Known Use

1957, in the meaning defined at sense 1

Rhymes for respiratory syncytial virus

• adenovirus
• baculovirus
• coronavirus
• enterovirus
• poliovirus
• antivirus
• herpesvirus
• parvovirus
• reovirus
• retrovirus
• rhinovirus
• rotavirus

Medical Definition

respiratory syncytial virus

noun

1

: a pneumovirus (species Human orthopneumovirus of the genus Orthopneumovirus) that usually causes mild infections of the upper and lower respiratory tract, that is spread through contact with respiratory droplets, and that is characterized especially by fever, coughing, congestion, and runny nose but may progress to bronchiolitis and pneumonia especially in infants, the elderly, and immunocompromised individuals

Respiratory syncytial virus is the most important respiratory pathogen causing lower respiratory tract infection in infants and young children.

—David W. Smith et al., The New England Journal of Medicine

Note: Respiratory syncytial virus was initially identified in 1956 and was formerly classified as a paramyxovirus. Cells infected with the virus typically fuse with adjacent cells to form multinucleate syncytia.

called also RSV

2

: the illness caused by respiratory syncytial virus

… an expanding array of synthetic drugs is being clinically tested against many viral infections. … A handful already have been approved for medical use against herpes, influenza, and respiratory syncytial virus …, a common respiratory infection that usually is mild but can be life threatening to infants in poor health.

—Roland K. Robins, Chemical & Engineering News

called also RSV