Question Period Note: Respiratory Syncytial Virus

N/A

• This fall, a rise in pediatric hospitalizations for respiratory syncytial virus (RSV) is being reported across the United States, with some pediatric hospitals reporting being ‘overwhelmed’. Several factors are contributing to this, including a lack of normal exposure to the virus for children during the COVID-19 pandemic.
• A similar rise in Canada was observed but appears to be stabilizing (1,944 detections; 7.6% positive in the week ending November 19, 2022). RSV activity remains above expected levels, placing pressure on pediatric hospitals in Canada, but is approaching levels typical of this time of year.
• In Canada, activity of influenza is currently highest and increasing, especially in children and adolescents, compounding already pressured pediatric hospitals.
• The health and safety of people in Canada is the Government’s top priority.
• The Public Health Agency of Canada monitors for respiratory syncytial virus (RSV). Based on surveillance data from the week ending November 19, 2022, RSV activity in Canada has stabilized. Activity remains above expected levels for this time of year; however, it is approaching seasonal norms.
• RSV is a common respiratory virus and the most common cause of respiratory hospitalizations in children in Canada and worldwide. Most children will get an RSV infection before they turn two years old. While many infections with RSV are mild, children and infants under the age of two years are particularly at risk of serious complications of RSV infection, such as bronchiolitis or pneumonia, and may be hospitalized.
• We are aware of reports of increased pressure on the health care system across the country, especially pediatric hospitals, caused in part by RSV-related illness along with the co-circulation of COVID-19 and influenza. Strain on the healthcare system may further be compounded by a shortage of healthcare workers, and supply shortages of some over-the-counter medications.
• The use of personal protective practices, like staying home when sick, frequently washing your hands, covering your coughs and sneezes, and cleaning and disinfecting frequently touched surfaces can help prevent the spread of RSV and other seasonal respiratory viruses.

If pressed
• RSV, like seasonal influenza, causes annual seasonal epidemics. Due to reduced circulation of RSV during the winter months of 2020–2021 and 2021 2022, older children might now be at increased risk of severe RSV associated illness since they have likely not had typical levels of exposure to RSV during the past two seasons.
• Given that many public health measures used to prevent the spread of COVID-19 (such as gathering restrictions, lockdowns and mask mandates) have been eased, we expect increased cases of RSV and other respiratory viruses for the current respiratory illness season. This occurred with RSV last fall when an earlier than typical RSV epidemic placed time-limited, regional pressures on pediatric hospitals in Canada over the fall and into the winter.
• Other factors that may also be contributing to a resurgence in respiratory illnesses, like RSV, include more individuals moving into indoor settings due to the colder weather and a lack of population-level immunity given the lower circulation of viruses during previous years of the pandemic, especially in children.
• The federal government is committed to continue working with our provincial and territorial counterparts, regulators, health workers and Canadians to identify and implement strategies to address the current health human resource crisis. Collaborative work is underway to identify concrete solutions.

RSV surveillance
Canada participates in national and international activities to detect and monitor the spread of RSV in humans. The Public Health Agency of Canada (PHAC) maintains the Respiratory Virus Detection Surveillance System, Canada’s national surveillance system that monitors the circulation of seasonal respiratory viruses, including RSV, each week. PHAC also works with the Canadian Pediatric Society to support enhanced surveillance pilot projects on pediatric RSV to prepare for new treatments and vaccines to reduce the burden of RSV in vulnerable children.
Vaccine Development and Treatment
There is currently no vaccine to prevent RSV infections, but there are a few that are currently in development. There is a drug (palivizumab) that can help protect young infants at high risk for severe disease. Passive immunization with palivizumab is the only pharmaceutical option for RSV prevention at this time. This is an antibody recommended for high-risk infants. Canada’s National Advisory Committee on Immunization has issued guidance on the recommended use of palivizumab to reduce complications of RSV infection in infants.
Several vaccines and preventative agents are in development to prevent RSV disease in children, infants and older adults. Earlier this fall, GlaxoSmithKline and AZ/Sanofi (collaboration) announced their new drug submissions to Health Canada for prevention of severe diseases due to RSV.
Prevention
With the co-circulation of COVID-19, RSV and influenza across many communities in Canada, PHAC continues to recommend a vaccine PLUS approach, which includes the layered use of personal protective practices. Many of these measures have been used before and during the COVID-19 pandemic and continue to be important everyday practices. These include:
• getting your COVID-19 and annual influenza vaccines;
• staying home when sick;
• improving indoor ventilation, when possible, such as opening a window or door;
• frequently cleaning your hands;
• avoiding touching your face with unclean hands;
• covering your coughs and sneezes with a tissue or the bend of your arm; and
• cleaning and disinfecting high-touch surfaces and objects.

In addition, to reduce the spread of COVID-19, PHAC continues to recommend that individuals properly wearing a well-constructed, well-fitting mask or respirator in public indoor settings, especially if they are crowded or poorly ventilated. Masks can also act as an added layer of protection against other respiratory illnesses such as RSV and influenza.

• RSV is one of several seasonal respiratory viruses that circulate in the colder months from fall through spring in Canada. Among non-SARS-CoV-2 seasonal respiratory viruses, activity of influenza is highest and increasing; activity of both influenza and RSV remain elevated as of the week ending November 19, 2022.
• RSV is the leading cause of acute lower respiratory tract infections in children, nationally and internationally. Approximately 95% of children <2 years old develop at least one RSV infection.
• RSV is primarily spread via respiratory particles when a person coughs or sneezes, and through direct contact with a contaminated surface.
• Canada typically sees increasing RSV activity over the fall and a seasonal RSV epidemic during the winter months, peaking in December/January, each year.
• Based on surveillance data from the week ending November 19, 2022, RSV activity in Canada has stabilized (1,944 detections; 7.6% positive). Activity remains above expected levels for this time of year but is approaching seasonal norms.
• The health risks from RSV are low for most Canadians, and people who get RSV will usually have mild symptoms similar to the common cold, such as coughing and sneezing, and will recover quickly. However, infants, young children and, to a lesser degree, seniors, are at a higher risk of severe illness compared to the general population.
• The federal Health Portfolio estimates that, prior to the COVID-19 pandemic, each year RSV led to an average of 1,042 hospitalizations per 100,000 infants under 2 years of age, 106 hospitalizations per 100,000 children ages 2 to 4 years, and 52 hospitalizations per 100,000 seniors aged 65+. In comparison, hospitalizations for the general population attributed to RSV are estimated at 27 per 100,000 people annually.
• Currently, there is no vaccine to prevent RSV. Passive immunization with palivizumab is the only pharmaceutical option for RSV prevention at this time. This is an antibody recommended for high-risk infants.
• While there is no vaccine currently available, Health Canada received a submission from GlaxoSmithKline on October 25 of this year for a vaccine for adults 60 years of age and older. Pfizer has also notified Health Canada of its plans to submit two vaccine candidates in 2023 – one for seniors and one for pregnant women. All submissions are reviewed by Health Canada using an independent process based on scientific rigour and medical evidence.
Until a vaccine is available, the best guidance to protect each other, especially those at risk, is for all Canadians to practice effective public health measures such as staying home when sick, wearing a mask, and practicing frequent hand hygiene and respiratory etiquette. These actions can help reduce the spread not only of RSV, but also of other respiratory illnesses such as seasonal flu, especially when used together in a layered approach.