Merck (MRK) said Thursday that Health Canada has approved Enflonsia, or clesrovimab, to prevent respiratory syncytial virus, or RSV, lower respiratory tract disease in newborns and infants entering their first RSV season.

Availability may vary by province and territory, depending on local reimbursement programs, the company added.

Enflonsia is a monoclonal antibody that can help protect for up to five months, covering a typical RSV season. The approval is based on results from Merck's clinical trials, including the phase 2b/3 CLEVER trial and the phase 3 SMART trial, the company said.

Shares of Merck were nearly 2% up in recent trading.

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