CSL (ASX:CSL) will likely take time to rerate due to the impact of vaccine fatigue after the COVID-19 pandemic and lack of growth in its specialty product segment, according to a Sunday note from Jefferies.

Jefferies believes most of CSL's businesses operate in a logical and still underdeveloped market with room to grow.

The investment firm said that the share price continues to look "too cheap."

Jefferies noted that the European Union launch of the company's flu vaccine called aTIVc is now expected to be around fiscal 2028, with the US release delayed even further due to policy changes.

Jefferies reaffirmed its buy rating on CSL and lowered its price target to AU$237 from AU$240.

The company's shares rose almost 1% in recent Tuesday trade.