Vaxcyte raises ~$1bn via equity and convertible notes to fund VAX-31
Vaxcyte has priced two concurrent public offerings that are expected to raise approximately $1 billion in gross proceeds, with the capital earmarked to advance its lead pneumococcal conjugate vaccine candidate, VAX-31, through late-stage trials and toward a potential first commercial launch in the United States.
The San Carlos, California company priced 7,412,500 shares of common stock at $64.00 per share, alongside pre-funded warrants for a further 400,000 shares priced at $63.999 each. Separately, it priced $500 million in 1.50% convertible senior notes due October 2032. Underwriters hold 30-day options to purchase an additional 1,171,875 shares and up to $75 million of additional notes, respectively. The offerings are expected to close on 9 October 2026.
The convertible notes carry an initial conversion price of approximately $89.60 per share, representing a roughly 40% premium to the equity offering price. Vaxcyte may settle conversions in cash, stock or a combination, at its election. The notes become redeemable at the company's option from October 2029, subject to the share price exceeding 130% of the conversion price for a defined period.
Use of proceeds
Vaxcyte has set out a detailed deployment plan. The bulk of the capital will support ongoing Phase 3 adult studies for VAX-31 under the OPUS programme, which includes a concomitant administration study with a seasonal influenza vaccine (OPUS-2) and a study in previously vaccinated adults (OPUS-3), both described as enrolled. A Phase 2 infant dose-finding study is also enrolled, with topline immunogenicity data anticipated from both the primary three-dose series and a booster dose.
Beyond clinical trials, the proceeds will fund manufacturing scale-up and inventory build ahead of a prospective US adult launch, as well as medical affairs and commercial infrastructure. Vaxcyte also intends to direct a portion toward earlier-stage pipeline candidates, including VAX-24, a 24-valent PCV with positive Phase 2 data in adults and infants, its Group A Streptococcus candidate VAX-A1 (currently in Phase 1), and VAX-GI, a Shigella vaccine in earlier development.
Market context
The pneumococcal vaccine market is one of the largest and most commercially durable segments in all of vaccines, currently dominated by Pfizer's Prevnar 20 (a 20-valent PCV) and Merck's Vaxneuvance (15-valent). Both candidates are widely used across adult and paediatric populations, but neither covers the full breadth of serotypes that contribute meaningfully to invasive pneumococcal disease globally.
Vaxcyte's pitch to investors rests on breadth: VAX-31 is positioned as the widest-spectrum PCV candidate currently in clinical development. The company manufactures using its XpressCF cell-free protein synthesis platform, exclusively licensed from Sutro Biopharma, which it argues can produce difficult-to-make conjugate antigens with greater fidelity than conventional cell-based methods. Whether that translates into a clinically and commercially meaningful differentiation will depend on immunogenicity and safety data not yet fully disclosed.
A raise of this scale, combining equity dilution with a sizeable convertible instrument, signals that the board is positioning for a multi-year runway through to potential commercialisation rather than a near-term partnering event. Analysts will note the decision to retain full control rather than seek a co-commercialisation partner at this stage, which concentrates both the upside and the execution risk within Vaxcyte itself. Topline data readouts from the OPUS-2 and OPUS-3 studies, and from the infant programme, are the key value inflection points to watch in the near term.