Option to Purchase Additional Shares
We have granted an option to the underwriters, exercisable for 30 days after the date of this prospectus supplement, to purchase up to
additional shares of our common stock from us, at the public offering price, less the underwriting discounts and commissions. If the underwriters
exercise this option, each will be obligated, subject to conditions contained in the underwriting agreement, to purchase a number of additional shares of our common stock proportionate to that underwriters initial amount reflected in the above
table.
No Sales of Similar Securities
We have agreed, subject to limited exceptions, that we will not: (i) directly or indirectly, offer, pledge, sell, contract to sell, sell
any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of any shares of common stock or any securities convertible into or exercisable or
exchangeable for common stock or file or confidentially submit any registration statement under the Securities Act of 1933, as amended, with respect to any of the foregoing or (ii) enter into any swap or any other agreement or any transaction
that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the common stock, whether any such swap or transaction described in clause (i) or (ii) above is to be settled by delivery of common stock
or other securities, in cash or otherwise, in each case without the prior written consent of BofA Securities, Inc. and Jefferies LLC, for a period continuing to and including the date 60 days after the date of this prospectus supplement.
Our executive officers, directors and certain of our existing security holders have entered into
lock-up agreements with the underwriters prior to commencement of this offering pursuant to which each of these persons, with limited exceptions, for a period continuing to and including the date 60 days after
the date of this prospectus supplement, may not, without the prior written consent of BofA Securities, Inc. and Jefferies LLC: (i) directly or indirectly, offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase
any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of any shares of the Companys common stock or any securities convertible into or exercisable or exchangeable for common stock, or
exercise any right with respect to the registration of any shares of the Companys common stock or any securities convertible into or exercisable or exchangeable for common stock, or file, cause to be filed or cause to be confidentially
submitted any registration statement in connection therewith, under the Securities Act of 1933, as amended, or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the
economic consequence of ownership of the Companys common stock or any securities convertible into or exercisable or exchangeable for common stock, whether any such swap or transaction is to be settled by delivery of common stock or other
securities, in cash or otherwise.
Nasdaq Select Global Market Listing
The shares of our common stock are listed on the Nasdaq Global Select Market under the symbol PCVX. We do not intend to list the
pre-funded warrants on the Nasdaq Global Select Market or any other national securities exchange or nationally recognized trading system.
Price
Stabilization and Short Positions
Until the distribution of the shares is completed, SEC rules may limit underwriters and selling
group members from bidding for and purchasing our common stock. However, the representatives may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price.
In connection with the offering, the underwriters may purchase and sell our common stock in the open market. These transactions may include
short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of
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