Tekla Healthcare Opportunities Fund : Joint Proxy Statement

TEKLA HEALTHCARE INVESTORS

TEKLA LIFE SCIENCES INVESTORS

TEKLA HEALTHCARE OPPORTUNITIES FUND

TEKLA WORLD HEALTHCARE FUND

100 Federal Street, 19th Floor

Boston, Massachusetts 02110

[phone]

IMPORTANT SHAREHOLDER INFORMATION

We are pleased to enclose the Notice of Special Joint Meetings and Joint Proxy Statement for the Special Joint Meetings of Shareholders (with any adjournments or postponements thereof) of Tekla Healthcare Investors ("HQH"), Tekla Life Sciences Investors ("HQL"), Tekla Healthcare Opportunities Fund ("THQ") and Tekla World Healthcare Fund ("THW") (each a"Fund" and collectively, the"Funds") to be held at 100 Federal Street, 19th Floor, Boston, Massachusetts 02110. The first special meeting will be held at 9:00 a.m. ET on August 14, 2023 (the "First Meeting") and the second special meeting will be held at 9:30 a.m. ET on August 14, 2023 (the"Second Meeting" and together with the First Meeting, the"Special Meetings").

The Funds' Boards of Trustees (each a"Board" and collectively, the"Boards"), including the Trustees who are not"interested persons" (the"Independent Trustees") as defined in the Investment Company Act of 1940, as amended, are asking you to approve significant, and we believe, positive changes to the Funds.

Tekla Capital Management LLC ("Tekla"), the investment adviser to each of the Funds, has entered into a purchase agreement (the"Purchase Agreement") with abrdn Inc. pursuant to which Tekla has agreed to sell certain assets to abrdn Inc. relating to Tekla's advisory business for the Funds (the "Asset Transfer"). The completion of the Asset Transfer is subject to certain approvals by the shareholders of each Fund as well as other conditions set forth in the Purchase Agreement.

At the First Meeting, you will be asked to approve new investment advisory agreements between the Funds and abrdn Inc. (each a "New Advisory Agreement" and collectively, the "New Advisory Agreements") (the "First Meeting Proposal"). Copies of the New Advisory Agreements are attached as Exhibit A to the enclosed joint proxy statement. The Funds' investment management team, investment objectives, principal investment policies and investment advisory fees will not change as a result of the proposed change in investment adviser to abrdn Inc., an experienced manager and operator of U.S. registered closed-endfunds.

In addition, at the Second Meeting, you will be asked to elect four new Trustees to serve as Trustees of the Funds (the "New Trustees") (the "Second Meeting Proposal" and together with the First Meeting Proposal, the "Proposals"). The New Trustees would replace four of the Trustees currently serving on the Boards (the "Resigning Trustees"). Two existing Trustees would continue to serve on the Boards after completion of the Asset Transfer (each a"New Board" and collectively, the"New Boards").

If (i) shareholders of all four of the Funds approve the New Advisory Agreements; (ii) shareholders of all four of the Funds elect the New Trustees; and (iii) the other conditions in the Purchase Agreement are satisfied or waived, abrdn Inc. will serve as investment adviser to the Funds (employing the same investment team currently employed by Tekla) and the New Trustees will replace the Resigning Trustees effective upon the completion of the Asset Transfer, which is expected to occur as soon as reasonably practicable following the affirmative vote of shareholders of the Funds, currently anticipated for the third quarter of 2023.

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If (i) shareholders of one or more Funds do not approve the New Advisory Agreements; (ii) shareholders of one or more Funds do not elect the New Trustees; or (iii) the other conditions in the Purchase Agreement are not satisfied or waived, then the Asset Transfer will not be completed, the Purchase Agreement will terminate, Tekla will continue to serve as investment adviser to the Funds and all of the current Trustees will continue to serve as Trustees of the Funds.

The enclosed Notice of Special Joint Meetings outlines the items for you to consider and vote upon. The enclosed Joint Proxy Statement gives details about each proposal and should be carefully read and considered before you vote.

The Boards believe each Proposal is in the best interests of the Funds and their shareholders and unanimously recommend that you vote "FOR" each Proposal.

As a shareholder of record of one or more Funds as of the close of business on June 16, 2023, the record date, you are entitled to notice of, and to vote at, the Special Meetings; therefore, we are asking that you please take the time to cast your vote prior to the August 14, 2023 Special Meetings. If you have any questions regarding the proposals, please call the Funds' proxy solicitor, Okapi Partners LLC, toll-free at [phone]. If you do not vote, you may receive a phone call from Okapi Partners LLC reminding you to vote your shares.

As always, we appreciate your support.

Sincerely,

Daniel R. Omstead, Ph.D.

President

July 10, 2023

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QUESTIONS AND ANSWERS

REGARDING THE JOINT PROXY STATEMENT AND

SPECIAL JOINT MEETINGS OF SHAREHOLDERS

While we strongly encourage you to read the full text of the enclosed Joint Proxy Statement, we are also providing you with a brief overview of the proposals ("Proposals") to be considered at the Special Joint Meetings of Shareholders (with any adjournments or postponements thereof) of Tekla Healthcare Investors ("HQH"), Tekla Life Sciences Investors ("HQL"), Tekla Healthcare Opportunities Fund ("THQ") and Tekla World Healthcare Fund ("THW") (each a "Fund" and collectively, the "Funds"). Your vote is important.

Q. Why are you sending me this information?

A.You are receiving this Joint Proxy Statement because you own shares of one or more of the Funds and have the right to vote on the very important Proposals concerning your investment.

Q. What am I being asked to vote "FOR" in this Joint Proxy Statement?

A. At the first special meeting (the "First Meeting") you will be asked to approve a new investment advisory agreement (each a "New Advisory Agreement" and collectively, the "New Advisory Agreements") between each Fund and abrdn Inc. (the"First Meeting Proposal").

At the second special meeting (the"Second Meeting" and together with the First Meeting, the"Special Meetings") you will be asked to elect four new Trustees to serve as Trustees of each Fund (the "New Trustees") (the "Second Meeting Proposal" and together with the First Meeting Proposal, the "Proposals").

If (i) shareholders of all four of the Funds approve the New Advisory Agreements; (ii) shareholders of all four of the Funds elect the New Trustees; and (iii) the other conditions in the Purchase Agreement (defined below) are satisfied or waived, abrdn Inc. will serve as investment adviser to the Funds (employing the same investment team currently employed by Tekla Capital Management LLC ("Tekla")) and the New Trustees will replace four of the Trustees currently serving on the Boards effective upon the completion of the Asset Transfer (defined below), which is expected to occur as soon as reasonably practicable following the affirmative vote of shareholders of the Funds, currently anticipated for the third quarter of 2023.

If (i) shareholders of one or more Funds do not approve the New Advisory Agreements; (ii) shareholders of one or more Funds do not elect the New Trustees; or (iii) the other conditions in the Purchase Agreement are not satisfied or waived, then the Asset Transfer will not be completed, the Purchase Agreement will terminate,Tekla will continue to serve as investment adviser to the Funds and all of the Trustees currently serving as Trustees of the Funds (the"Current Trustees") will continue to serve as Trustees of the Funds.

Q. How do the Boards of Trustees recommend that I vote?

A. The Boards of Trustees (each a "Board" collectively, the "Boards") of the Funds unanimously recommend that shareholders vote FOR the Proposals. If no instructions are indicated on your proxy, the representatives holding proxies will vote in accordance with the recommendations of the Boards.

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Q. What changes are being proposed to the Funds' investment adviser and why are the Boards recommending abrdn Inc.?

A. Tekla currently serves as the investment adviser to the Funds. On June 20, 2023, Tekla entered into a purchase agreement (the"Purchase Agreement") with abrdn Inc. pursuant to which Tekla has agreed to sell certain assets to abrdn Inc. relating to Tekla's advisory business for the Funds (the "Asset Transfer"). The Asset Transfer is subject to receipt of the necessary approvals of the New Advisory Agreements, election of the New Trustees and satisfaction or waiver of certain other conditions. More specifically, under the Purchase Agreement, in exchange for cash payment at the completion of the Asset Transfer and subsequent "earn out" payments tied to revenues following the Asset Transfer, Tekla has agreed to transfer to abrdn Inc., with certain exceptions: (i) all right, title and interest of Tekla and its affiliates in and to the books and records or documents to the extent solely used or held for use with respect to the Funds; (ii) the non-exclusive right to use each Fund's performance information in abrdn Inc.'s performance information to the extent permitted by applicable law; (iii) all goodwill of Tekla's business attributable to the Funds; and (iv) certain other contracts and rights of Tekla, including the contracts required for the operation of Tekla's business attributable to the Funds (excluding the Tekla Advisory Agreements, as defined below).

Tekla recommended that the Boards consider and approve the New Advisory Agreements with abrdn Inc. with respect to each Fund upon the determination that it would be in the best interest of each Fund's shareholders. At an in-personmeeting held on June 26, 2023, the Trustees, including all of the

Trustees who are not "interested persons" (the "Independent Trustees") as defined in the Investment Company Act of 1940, as amended (the "1940 Act"), approved the New Advisory Agreement for each Fund and unanimously recommended that shareholders of each Fund approve the New Advisory Agreement for such Fund. abrdn Inc., its parent company, abrdn plc, and its affiliates are collectively referred to as"abrdn." abrdn Inc. is an indirect wholly-ownedsubsidiary of abrdn plc.Tekla and abrdn Inc. are not affiliates of each other. The Joint Proxy Statement provides additional information about abrdn and the New Advisory Agreements.

The Funds are not a party to the Purchase Agreement; however, the completion of the Asset Transfer is subject to approval by the shareholders of all four of the Funds of both of the Proposals described in the enclosed Joint Proxy Statement and the satisfaction or waiver of certain other conditions in the Purchase Agreement.

If shareholders of all four of the Funds approve both Proposals and the other conditions in the Purchase Agreement are satisfied or waived, the New Advisory Agreements will become effective and abrdn Inc. will assume its responsibilities thereunder upon the completion of the Asset Transfer, which is expected to occur as soon as reasonably practicable following the affirmative vote of shareholders of the Funds, currently anticipated for the third quarter of 2023.

If (i) shareholders of one or more Funds do not approve the New Advisory Agreements; (ii) shareholders of one or more Funds do not elect the New Trustees; or (iii) the other conditions in the Purchase Agreement are not satisfied or waived, then the Asset Transfer will not be completed and the Purchase Agreement will terminate.

abrdn plc and its subsidiaries, including abrdn Inc., constitute one of the world's largest asset management firms. abrdn Inc. has extensive experience in managing closed-end funds in markets directly relevant to the Funds. As of December 31, 2022, abrdn and its affiliates had approximately $452 billion in assets under management. Moreover, closed-end funds are an important element of

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the abrdn client base in the U.S. and globally. abrdn Inc. and its affiliates managed thirty-eight closed- end funds, totaling $29.8 billion in assets as of January 24, 2023. If the New Advisory Agreements are approved, the Funds would complement, rather than compete with, abrdn's U.S. closed-end fund family. abrdn has substantial experience in assimilating closed-end funds into its family of funds.

It is currently anticipated that substantially all of members of the investment team currently managing the Funds at Tekla would continue to manage the Funds as full-time employees of abrdn, Inc. abrdn Inc. is also committed to its asset management business and, in particular, its larger closed-end fund platform, has knowledge of the closed-end fund marketplace, and has dedicated closed-end fund investor services professionals. For further details on the Boards' decision to recommend abrdn Inc., please see"Board Consideration of the New Advisory Agreements" in the Joint Proxy Statement.

The Boards believe that approval of the New Advisory Agreements would be in the best interests of the Funds.

Q. Will the approval of the New Advisory Agreements result in different terms that affect my shares?

A. No. The New Advisory Agreements will not affect your shares.You will still own the same shares in the applicable Fund(s) and your shares will have the same rights and preferences. The terms of the New Advisory Agreements are materially identical to the terms of the current investment advisory agreements between Tekla and the Funds (the"Tekla Advisory Agreements"), and the New Advisory Agreements will have the same advisory fee structures as are currently in effect, which will result in identical advisory fee rates. As a result, the advisory fees you pay as a shareholder will not increase

as a result of the Asset Transfer.

The Funds' Operating Expenses (as defined below) are expected to decrease following the Asset Transfer. abrdn will seek to achieve savings through scale and efficiency in the Funds' operations (for instance, by driving better terms from fund service providers). In addition, at a minimum, abrdn Inc. has contractually agreed to limit, for a period of two years following completion of the Asset Transfer, the Operating Expenses of each Fund to an amount that is at least 0.02% less than the Operating Expenses of the Fund, as reported as a percentage of average net assets in the Fund's annual report for the fiscal year ended September 30, 2022.

	2022 Operating Expenses1 as a
Fund	Percentage of Net Assets2	Operating Expense Limit

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2

HQH	1.19%	1.17%
HQL	1.38%	1.36%
THQ	1.46%	1.44%
THW	1.53%	1.51%

Operating Expenses means aggregate expenses incurred by each Fund in any fiscal year, including but not limited to investment advisory fees (but excluding borrowing costs, taxes, brokerage commissions, and any non-routine expenses). Reported in the Financial Highlights in the relevant Fund's annual report to shareholders for the fiscal year ended September 30, 2022.

If shareholders of all four of the Funds approve both Proposals and the other conditions in the Purchase Agreement are satisfied or waived, abrdn Inc. will assume responsibility for management of the Funds' investment portfolios as soon as reasonably practicable following the affirmative vote of shareholders of the Funds, currently anticipated for the third quarter of 2023. For further details, please see"How will the Asset Transfer affect the value of my investment?" below.

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