Vanguard Inflation-Protected Securities Fund Summary Prospectus

April 27, 2010

Institutional Shares

Vanguard Inflation-Protected Securities Fund Institutional Shares (VIPIX)

The Fund’s statutory Prospectus and Statement of Additional Information dated April 27, 2010, and financial highlights information from the most recent shareholder report are incorporated into and made part of this Summary Prospectus by reference.

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund online at www.vanguard.com/prospectus. You can also get this information at no cost by calling 800-662-7447 or by sending an e-mail request to online@vanguard.com.

The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Investment Objective

The Fund seeks to provide inflation protection and income consistent with investment in inflation-indexed securities.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy and hold Institutional Shares of the Fund.

Shareholder Fees
(Fees paid directly from your investment)
Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)
Management Expenses	0.06%
12b-1 Distribution Fee	None
Other Expenses	0.03%
Total Annual Fund Operating Expenses	0.09%

Example

The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you invest $10,000 in the Fund’s shares. This example assumes that the Shares provide a return of 5% a year and that operating expenses remain the same. The results apply whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	3 Years	5 Years	10 Years
$9	$29	$51	$115

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Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 14% of the average value of its portfolio.

Primary Investment Strategies

The Fund invests at least 80% of its assets in inflation-indexed bonds issued by the U.S. government, its agencies and instrumentalities, and corporations. The Fund may invest in bonds of any maturity; however, its dollar-weighted average maturity is expected to be in the range of 7 to 20 years. At a minimum, all bonds purchased by the Fund will be rated “investment-grade.”

Primary Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range, like the fluctuations of the overall bond market. The Fund’s performance could be hurt by:

• Income fluctuations. The Fund’s quarterly income distributions are likely to fluctuate considerably more than the income distributions of a typical bond fund. Income fluctuations associated with changes in interest rates are expected to be low; however, income fluctuations associated with changes in inflation are expected to be high. Overall, investors can expect income fluctuations to be high for the Fund.

• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk is expected to be moderate for the Fund.

• Manager risk, which is the chance that poor security selection or focus on securities in a particular sector, category, or group of companies will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund‘s Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of a relevant market index. Keep in mind that the Fund’s

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past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at www.vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns—Institutional Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 5.37% (quarter ended March 31, 2009), and the lowest return for a quarter was –3.93% (quarter ended December 31, 2008).

Average Annual Total Returns for Periods Ended December 31, 2009

			Since
			Inception
			(Dec. 12,
	1 Year	5 Years	2003)
Vanguard Inflation-Protected Securities Fund Institutional Shares
Return Before Taxes	11.03%	4.49%	5.02%
Return After Taxes on Distributions	10.32	2.92	3.32
Return After Taxes on Distributions and Sale of Fund Shares	6.79	2.91	3.29
Barclays Capital U.S. Treasury Inflation Protected
Securities Index
(reflects no deduction for fees, expenses, or taxes)	11.41%	4.63%	5.17%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After

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Taxes on Distributions and Sale of Fund Shares will be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Investment Advisor

The Vanguard Group, Inc.

Portfolio Managers

John W. Hollyer, CFA, Principal of Vanguard. He has co-managed the Fund since its inception in 2000.

Kenneth E. Volpert, CFA, Principal of Vanguard and head of Vanguard’s Taxable Bond Group. He has co-managed the Fund since its inception in 2000.

Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website at www.vanguard.com, by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The following table provides the Fund’s minimum initial and subsequent investment requirements.

Account Minimums	Institutional Shares
To open and maintain an account	$5 million
To add to an existing account	$100 (other than by Automatic Investment Plan,
	which has no established minimum).

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares or related services.

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Vanguard Inflation-Protected Securities Fund Institutional Shares—Fund Number 1190

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© 2010 The Vanguard Group, Inc. All rights reserved.
Vanguard Marketing Corporation, Distributor.

SPI1190 042010