Respiratory Syncytial Virus (RSV) Information: The Vaccine for RSV Virus

June 19, 2024

Respiratory Syncytial Virus

Respiratory syncytial (sin-SISH-uhl) virus (RSV) is a common respiratory virus that causes cold-like symptoms and typically spreads during respiratory virus season (fall, winter, and spring months in the Northern Hemisphere). RSV can affect anyone, but it has the potential to be most severe for infants, young children, older adults, and those with compromised immune systems—similar to other respiratory viruses like influenza and COVID-19. The Centers for Disease Control and Prevention (CDC) describes RSV as "a cause of severe respiratory illness across the lifespan," with annual data that reflects "approximately 60,000-160,000 hospitalizations and 6,000-10,000 deaths among adults 65 years and older" in the United States. 1

RSV is spread like other respiratory viruses; the virus enters the body through the eyes, mouth, or nose via infected droplets (usually spread by an infected person coughing or sneezing nearby). Shaking hands or touching contaminated surfaces or objects can also spread RSV. The spread of RSV is particularly common amongst infants and young children due to ‘high traffic’ or consistently touched surfaces (cribs, handles or railings, toys, and countertops) in homes and childcare settings. RSV can continue to spread for up to four (4) weeks, even after symptoms disappear, which can make the virus especially difficult to contain.

RSV is one of the three viruses in what some medical professionals refer to as the “tripledemic” because it often spreads rapidly in the same ways and same seasons as COVID-19 and influenza. Like COVID-19 and flu, the best protection against severe RSV is vaccination. And while the RSV vaccine is not yet regularly recommended for all age groups, several RSV vaccines and products are Food and Drug Administration (FDA) approved and recommended for vulnerable populations. It is important to discuss condition(s), risk factors, and protection methods with a healthcare professional.

RSV Symptoms in Children and Adults

As its full name suggests, RSV affects the respiratory tract and lungs. People usually start to show symptoms four (4) to six (6) days after infection. RSV symptoms may appear in stages over time and may include:

  • Congested or runny nose
  • Sore throat
  • Headache
  • Coughing
  • Sneezing
  • Fever
  • Decreased appetite
  • Wheezing

Many children and adults recover from RSV within a week or two, but vulnerable populations can experience severe symptoms, hospitalization, or death. Seek immediate medical attention if you notice the following signs of severe RSV:

  • High fever
  • Severe cough
  • Wheezing (a high-pitched noise that's usually heard upon exhale)
  • Rapid breathing or difficulty breathing (if this occurs, individuals may prefer to sit up rather than lie down)
  • Bluish color of the skin (particularly the lips and nail beds) due to lack of oxygen (cyanosis)

Highly sensitive rRT-PCR tests are recommended when testing older children and adults for RSV. RSV rRT-PCR tests are now commercially available. Antigen tests are not as sensitive for older children and adults because they may have lower viral loads in their respiratory specimens. Medical professionals should consult experienced laboratories and technicians for more information on the interpretation of results.

RSV Symptoms in Infants

Babies twelve (12) months and younger (infants) are considered a very vulnerable population when it comes to RSV. Babies six (6) months and younger and premature infants are also incredibly vulnerable to RSV and severe complications.

In infants, RSV symptoms to look out for include:

  • Breathing difficulties
  • Irritability or crankiness
  • Decreased movement or activity

Infants are also the most affected population when it comes to severe RSV. Seek immediate medical attention if you see the following signs and symptoms of severe RSV in an infant:

  • Short, shallow, and rapid breathing
  • Struggling to breathe (where chest muscles and skin pull inward with each breath)
  • Cough
  • Poor feeding
  • Unusual tiredness

Antigen and rRT-PCR detection tests are effective methods for diagnosing RSV infection in infants and young children.

Factors of Increased Risk and/or Severe RSV Disease

Infants and young children are often considered the most vulnerable population when it comes to the spread of respiratory syncytial virus. By age two (2), most children will have been infected with RSV. Children who attend childcare facilities or who have siblings or close relatives who spend time in school settings are at a higher risk of RSV exposure and reinfection. It is possible to be infected with RSV more than once, even more than once in the same season. RSV vaccination is the best protection for vulnerable individuals to avoid severe disease.

People at increased risk of severe or sometimes life-threatening RSV disease include:

  • Infants, especially premature infants or babies who are 6 months or younger
  • Children who have heart disease present from birth (congenital heart disease) or chronic lung disease
  • Children or adults with weakened immune systems from diseases such as cancer or treatment such as chemotherapy
  • Children who have neuromuscular disorders, such as muscular dystrophy
  • Adults with chronic health conditions, especially heart disease or lung disease
  • Older adults, especially those aged 65 years and older
  • Infants exposed to tobacco smoke are at a higher risk of getting RSV and/or the potential for exhibiting more severe symptoms.

The CDC recommends that infants, some young children, and pregnant persons receive routine RSV immunization. Older adults (60+ and those with chronic medical conditions) should receive RSV immunization using shared clinical decision-making. It is important to discuss your condition(s), risk factors, and protection methods with a physician.

Adults who are high risk for severe RSV infection include:

  • Older adults
  • Adults with chronic heart or lung disease
  • Adults with compromised immune systems
  • Adults living in nursing homes or long-term care facilities
  • Adults with certain other underlying medical conditions

Complications of Severe RSV

The presence of severe symptoms may mean that RSV has caused more severe infections such as bronchiolitis (the inflammation of small airway passages in the lungs) or pneumonia (a lung infection). These infections occur when RSV spreads to the lower respiratory tract. Lung inflammation can be rather serious in infants, children, older adults, individuals with compromised immune systems, and/or people with chronic heart or lung conditions.

Hospitalizations due to RSV often occur due to breathing difficulties and/or dehydration. In severe cases, individuals may require supplemental oxygen, IV fluids (to provide sustenance), and/or intubation (insertion of a breathing tube) with automated ventilation.

Severe RSV may also cause and/or intensify:

  • Middle ear infections— If the virus enters the space behind the eardrum, one may experience an infection of the inner ear (otherwise known as otitis media). This is most common in infants and young children.
  • Repeated infections— Having RSV does not mean you can't get infected again. It's even possible to develop RSV again in the same season. Often an additional bout of RSV means the symptoms are less intense, but vulnerable populations can still experience severe symptoms.
  • Asthma— There may be a link between severe RSV in children and the development of asthma, a chronic condition—often beginning in childhood—where the airways in the lungs can become inflamed and narrowed, making it difficult to breathe. About 1 in 13 people in the U.S. live with asthma. 2

Vaccines for RSV

The best protection from developing severe RSV is to receive an age or condition-based RSV vaccine.

Respiratory syncytial virus (RSV) vaccines help by stimulating the immune system to produce antibodies against RSV, thereby preventing infection or reducing its severity. Vaccines for RSV work by introducing weakened or inactivated forms of the virus or specific viral proteins into the body, triggering the immune system to recognize and remember the virus. This immune response allows the body to mount a rapid and effective defense against RSV if exposed to the virus in the future. Additionally, RSV vaccines can help reduce the spread of the virus within communities, protecting vulnerable people who may be at higher risk of severe illness from RSV infection.

Vaccines for Adults 60+

Like vaccines for COVID-19 and influenza, there are RSV vaccines available for certain groups. For adults 60 years and older, the following vaccines are recommended:


RSV Vaccine for Pregnant People

For pregnant individuals, the following vaccines are recommended:

This is the only RSV vaccine that is FDA-approved for use in pregnant individuals, and it is to be administered between weeks 32-36 of pregnancy to protect the infant after birth. This vaccine is typically administered from September through January (in the US and Northern Hemisphere).*

RSV Antibodies for Infants and Young Children

If a fetus does not receive RSV immunization while in utero, it can receive RSV antibodies outside the womb. Preventative antibodies can help protect babies from severe disease. It is incredibly common for infants and young children to have had RSV by the time they reach two (2) years of age. RSV antibodies can help mitigate symptoms and severity of the disease in infants and young children.

Either RSV vaccination during pregnancy or administration to the infant upon birth is recommended to prevent RSV disease among infants, but both are not needed for most infants unless a healthcare provider deems it clinically necessary because an infant is at significant risk and needs additional or incremental doses. Some immunization schedules may also be adjusted based on local epidemiology.

The preventative antibodies available for infants are:

Use of nirsevimab (Beyfortus®), a monoclonal antibody, is recommended for infants younger than 8 months of age who were born during or are entering their first RSV season, and should only be administered if:

  • The birthing individual did not receive RSV vaccine during pregnancy.
  • The birthing individual's RSV vaccination status is unknown.
  • The infant was born within 14 days of RSV vaccination in utero.

The CDC advises 3 that some infants and young children (8 through 19 months of age) who are at increased risk for severe RSV disease should receive nirsevimab before the start of their second RSV season. This may include:

  • Children born prematurely or who have chronic lung disease
  • Children who are severely immunocompromised
  • Children with cystic fibrosis who exhibit severe disease
  • American Indian and Alaska Native children

Children who have not received nirsevimab but for whom it is recommended may receive nirsevimab at any time during RSV season.

Prescribing information for nirsevimab (Beyfortus®) can be found here.

Use of palivizumab (SYNAGIS®) is limited to some children younger than age 24 months (2 years) of age with certain conditions that increase their risk for severe RSV disease. It must be given once a month during RSV season.

Prescribing information for palivizumab (Synagis) can be found here.

What’s the difference between RSV Vaccines and RSV Antibodies?

Preventative antibodies prevent severe RSV disease. Although both monoclonal antibodies and vaccines provide protection, they provide protection differently. Nirsevimab (Beyfortus®) is an antibody that provides direct protection against RSV to the recipient (known as passive immunization). RSV Vaccines—AREXVY and ABRYSVO™—stimulate the recipient's own immune system to mount an immune response, which includes making antibodies (known as active immunization).

Additional Data and RSV Prevention Methods

The CDC's National Respiratory and Enteric Virus Surveillance System (NREVSS) collects data and shows RSV rates and trends by state and region. The CDC describes NREVSS as "a laboratory-based system that monitors temporal and geographic circulation patterns (patterns occurring in time and place) of respiratory syncytial virus (RSV), human parainfluenza viruses (HPIV), human metapneumovirus (HMPV), respiratory adenoviruses, human coronavirus, rotavirus, and norovirus. In this surveillance system, participating U.S. laboratories voluntarily report weekly to CDC the total number of weekly aggregate tests performed to detect these viruses, and the weekly aggregate positive tests. They also report the specimen type, location, and week of collection. NREVSS allows for timely analysis of data to monitor viral seasons and circulation patterns." 4

Knowing where and when RSV is spreading can be helpful in protecting yourself and your community, especially if you know or care for anyone who might be at risk of severe RSV disease. Local epidemiology can also affect immunization recommendations and schedules, so be sure to discuss locality-specific spread and prevention methods, as well as immunization schedules and sites with your local medical professional or clinic staff.

You can take prevention measures to help reduce the spread of RSV and other respiratory illnesses in your household and communities.

How to prevent or mitigate the spread of RSV:

  • Stay home when sick.
  • Cover your coughs and sneezes with a tissue or your shirt sleeve, not your hands.
  • Avoid exposure and close contact with others exhibiting symptoms.
  • Do not share drinking glasses or utensils with others.
  • Wash your hands often with soap and water, and for at least 20 seconds.
  • Avoid touching your face with unwashed hands.
  • Clean frequently touched surfaces such as doorknobs, mobile devices, toys, and countertops.
  • Don't smoke.

Conclusion

RSV is a serious disease, and it can cause severe infection, hospitalization, and even death, especially for vulnerable populations.

It is also important to note that individuals who have recently had COVID-19, influenza, or another respiratory illness may be more susceptible to RSV or more severe symptoms due to lowered immunity; COVID-19, flu, and RSV can occur at the same time. Seek healthcare advice and testing if you or someone in your care is experiencing symptoms of respiratory illness.

Sources

  1. https://www.cdc.gov/respiratory-viruses/tools-resources/downloads/respiratory-disease-at-a-glance-508.pdf
  2. https://www.nih.gov/news-events/nih-research-matters/avoiding-rsv-infancy-reduces-asthma-risk#:~:text=Infection%20with%20RSV%20at%20a,often%2C%20it%20begins%20in%20childhood
  3. https://www.cdc.gov/vaccines/vpd/rsv/public/child.html
  4. https://www.cdc.gov/surveillance/nrevss/index.html

References

  1. https://www.cdc.gov/rsv/about/prevention.html
  2. https://www.cdc.gov/rsv/causes/index.html
  3. https://www.cdc.gov/rsv/about/symptoms.html
  4. https://www.cdc.gov/rsv/clinical/index.html#:~:text=Both%20rRT%2DPCR%20and%20antigen,90%25%20in%20this%20age%20group
  5. https://www.cdc.gov/rsv/high-risk/older-adults.html
  6. https://www.cdc.gov/surveillance/nrevss/rsv/region.html
  7. https://www.cdc.gov/surveillance/nrevss/rsv/state.html
  8. https://www.cdc.gov/vaccines/vpd/rsv/downloads/provider-job-aid-for-older-adults-508.pdf
  9. https://www.cdc.gov/vaccines/vpd/rsv/hcp/child-faqs.html
  10. https://www.cdc.gov/vaccines/vpd/rsv/hcp/pregnant-people-faqs.html#:~:text=RSVpreF%20(Abrysvo)%20vaccine%20is%20the,through%2036%20weeks%206%20days
  11. https://www.mayoclinic.org/diseases-conditions/respiratory-syncytial-virus/symptoms-causes/syc-20353098