When drugmaker Pfizer reported positive coronavirus vaccine results, the stock market sat up and took notice. Not only did Pfizer's shares pop more than 10%, but so did stocks across the market like entertainment giant Walt Disney and oil driller ConocoPhillips. Are there any stocks out there that are still cheap?

We asked three of our Motley Fool contributors what stocks they think are still bargains even after the vaccine-induced rally. They came back with Brookfield Infrastructure (BIP 1.91%) (BIPC 1.00%), Emerson Electric (EMR 0.39%), and Quanta Services (PWR 1.77%). Here's why they think these are good buys. 

A girl wearing a mask receives an injection in her arm.

Image source: Getty Images.

A price that's barely budged

John Bromels (Brookfield Infrastructure): News of the coronavirus vaccine certainly did give infrastructure asset manager Brookfield Infrastructure's shares a bit of a pop. But far from inflating its price to astronomical levels, it bumped its shares to a meager 0.5% year-to-date return.

That's surprising considering Brookfield's numerous advantages. As part of the Brookfield Asset Management (BN 2.33%) family, Brookfield Infrastructure boasts a top-notch management team that has capably guided the company's portfolio of natural gas pipeline networks, high-speed data networks, toll roads, and ports through the pandemic. And while many of Brookfield's infrastructure assets have continued to perform well -- especially its data infrastructure holdings -- its toll roads and ports have suffered, and will benefit from the eventual arrival of a coronavirus vaccine.

Brookfield's enterprise value-to-earnings before interest, taxes, depreciation, and amortization (EBITDA) ratio is a reasonable 17, and its yield of 4% is supported by strong cash flow from its growing asset base. With a price that's barely budged in 2020, and management expecting growth to accelerate moving forward, Brookfield Infrastructure looks like a buy.

Emerson Electric remains undervalued

Lee Samaha (Emerson Electric): Value stocks are often found in unloved areas of the market, and Emerson Electric is arguably in one of them right now. However, the good news is it's creating a good buying opportunity in a company whose best days are ahead of it.

The company generates 58% of its earnings from automation solutions. As such the company is always going to be seen as a play on capital spending in heavy industries -- not a great place to be when economic growth slows and energy prices slump. That said, there's a lot more to Emerson than oil and gas and the current valuation looks attractive for a company set to see sales turn positive again in 2021.

The remaining 42% of sales come from its commercial and residential solutions segment, with the bulk of it coming from heating and air-conditioning solutions and the rest coming from a motley collection of professional construction tools and home products. In fact, management sees the commercial and residential solutions growing 4% to 7% in its fiscal 2021, helping to offset the expected decline in automation solutions of 4% to 1%. Ultimately, management is guiding toward total full-year sales to be in the range of a 1% decline to a 2% increase.

That might not sound like an exciting figure but it hides the fact that Emerson's automation solutions sales are expected to finally turn positive in the second half of fiscal 2021. As such, Emerson is forecast to end 2021 with both segments growing at a mid-single-digit rate. Meanwhile, at the current price of $74 and based on management's guidance, the stock will be trading at a price-to-free cash flow multiple of 17.7 times while paying a 2.7% dividend yield. That's a pretty good value that makes Emerson Electric a good choice for dividend investors.

An infrastructure stock at your service

Scott Levine (Quanta Services): With the prospect of a vaccine inspiring shareholders earlier this week, there are plenty of stocks on my watch list whose price tags seem far less attractive than they did last week. But that isn't the case for Quanta Services. In fact, the stock looks downright enticing at the moment. Currently, shares are trading hands at 6.7 times operating cash flow -- a considerable bargain to their five-year average multiple of 22.4. Looking for further evidence of the company's alluring valuation? How about the fact that in terms of its earnings multiple, Quanta's stock is trading at 25 times trailing earnings, representing a discount to the 35.5 ratio of the S&P 500?

Providing investors with a service-oriented approach to the infrastructure sector, Quanta Services brands itself as "the leading specialty infrastructure solutions provider for the utility, energy and communications industries." A cursory glance at the company's recent third-quarter 2020 earnings report may appear uninspiring as the company reported revenue of $3.02 billion, narrowly beating analysts' expectations of $3.01 billion. Dig below the surface, though, and you'll find there's plenty to be charged up about. For one, Quanta reported a company record in terms of sales from its electric power infrastructure services segment revenue. But that's not the only broken record. Quanta also reported a company high $1.13 in quarterly diluted EPS from continuing operations, under generally accepted accounting principles (GAAP). And the company's future seems to be bright as well; in the last quarter, Quanta achieved a record total backlog of $15.1 billion.

Furthermore, based on the company's strong performance last quarter, management has a more auspicious view of how the company will fare in 2020. Quanta, for example, forecasts EBITDA of approximately $906 million, a notable increase over the near $813 million that it had forecast in the first quarter. But what has me really excited about the company is not the income statement, but the cash flow statement. For 2020, Quanta is forecasting free cash flow of about $700 million. For some perspective, Quanta has generated average annual free cash flow of $208 million over the past five years, according to Morningstar.

Between the company's noteworthy growth in its backlog and its free cash flow expectation for 2020, Quanta's stock certainly seems like a compelling opportunity.