Melbourne, April 24, 2026, 06:21 AEST
- CSL shares dropped to levels not seen in almost ten years after the U.S. military ended its requirement for flu vaccination.
- CSL’s Seqirus vaccine division is already contending with softer U.S. flu immunisation rates as the move lands.
- CSL has also announced new share buybacks totaling A$19.4 million, aiming to shore up investor confidence.
CSL Limited shares slid to lows not seen since 2017, hit by news that the U.S. military has scrapped its long-standing mandate for troops to get yearly flu shots. The move throws another demand hurdle at the Australian biotech’s vaccine arm.
Pressure is already on CSL. The Seqirus business brings in revenue with flu vaccines, and the U.S. stands as its top market. After softer demand for flu shots, a sluggish plasma rebound, and a string of earnings misses, investors have shaved value off the shares. Reuters said CSL stock slid up to 0.8% Thursday, putting it more than 25% lower in 2026. Reuters
Pentagon chief Pete Hegseth announced annual flu shots are now optional rather than required, leaving service members free to skip or get the vaccine as they choose. The move sounds straightforward, yet it rattles a market used to counting on military demand—especially with flu-shot uptake already down. U.S. Department of War
Marc Jocum, senior product and investment strategist over at Global X ETFs, described the Pentagon’s decision as “incremental pressure at the worst possible time.” Hebe Chen, market analyst with Vantage Markets, flagged “slowing earnings momentum” and noted CSL still hadn’t “found a floor.” Reuters
Back in February, CSL flagged an expected 6% to 8% drop in the U.S. seasonal flu vaccine market for 2025/26, pointing to weaker immunisation uptake and softer prices in the egg-based segment. Seqirus posted first-half revenue of US$1.65 billion, a 2% dip, though seasonal influenza sales edged up 1%, even as the U.S. market lagged.
CSL isn’t idle. According to a Thursday ASX filing, the company snapped up 148,686 shares on April 22, shelling out A$19.44 million. That brings its cumulative tally before that date to 5.75 million shares repurchased. With an on-market buyback—where shares are purchased directly via the exchange—the aim is typically to return capital and give a lift to earnings per share. CSL Limited
The filing put the buyback cap at US$750 million, set to expire June 30, 2026. CSL picked up its recent shares at prices from A$128.68 to A$136.33—each well under the ASX’s daily limit of A$144.44.
CSL’s effort to return capital comes amid a more challenging stretch operationally. In its February half-year report, the company posted a 4% decline in revenue, down to US$8.3 billion. Net profit after tax tumbled 81% to US$401 million, hit by restructuring charges and impairments. Stripping out acquisition amortisation and major one-offs, NPATA slid 7% to US$1.9 billion.
Back then, Chief Financial Officer Ken Lim acknowledged CSL was “not satisfied with our performance.” The company stuck to its fiscal 2026 targets: 2% to 3% revenue growth, and 4% to 7% NPATA growth, both figures before one-off restructuring charges and impairments. U.S. vaccine policy is now challenging that outlook.
It’s not just CSL feeling the impact. Sanofi, GSK, and AstraZeneca are players in the flu vaccine market as well, but following the U.S. military’s decision, Reuters said none of those firms — nor CSL Seqirus — responded to requests for comment. What sets CSL apart: Seqirus is listed as a core strategic unit, and flu vaccines make up a visible slice of its earnings. Reuters
The bear case hinges on mandates dropping, but that doesn’t wipe out every dose—some U.S. service members could opt in regardless. CSL is also making a push with its differentiated flu offerings and growing its foothold in Europe. Still, the risk is straightforward: if U.S. institutional orders soften and households continue backing away from vaccines, CSL will have limited margin for mistakes in the back half.
