The COVID-19 pandemic is affecting our social lives, as governmental authorities in most U.S. states have implemented drastic measures -- including social distancing -- to mitigate the spread of the disease. The outbreak also continues to wreak havoc on equity markets. Year to date, the S&P 500 is down by 20% (at writing), and things could get worse before they get better.

The silver lining for investors -- if there is one -- is that many stocks are now trading at dirt-cheap prices. And while it's important to note that nothing, including dividends, is certain in today's market, some great dividend stocks are on sale. In particular, here are two that you can currently buy for a discount: AbbVie (NYSE:ABBV) and Pfizer (NYSE:PFE)

1. AbbVie

Pharma giant AbbVie hasn't performed particularly well of late. Last year, the company's shares slid by about 4%, while the S&P 500 climbed by almost 29%. The reason behind AbbVie's poor performance in 2019 isn't a secret: Sales of the company's blockbuster drug Humira -- which treats several autoimmune disorders including plaque psoriasis and rheumatoid arthritis -- have been declining in Europe because of competition from biosimilars. Humira still accounts for the bulk of AbbVie's revenue. 

Letter blocks spelling out the word dividends.

Image source: Getty Images.

During fiscal 2019, Humira's net revenue came in at $19.2 billion, which represented about 57.6% of the company's total. However, AbbVie has a plan to decrease its top-line exposure to Humira. First, several of its products are currently gaining solid momentum. For instance, Skyrizi, a treatment for moderate to severe plaque psoriasis that the U.S. Food and Drug Administration (FDA) approved in April of 2019, racked up $355 million in sales last year, including $216 million in the fourth quarter alone. 

Cancer drug Venclexta also recorded revenue of $792 million in fiscal 2019, more than doubling its revenue from the year before. Imbruvica, another cancer drug, recorded revenue of $4.7 billion, a 35.8% year-over-year increase. AbbVie hopes that these products (and others) will gradually fill up some of the void left by Humira's international sales. AbbVie also announced in June that it would acquire Allergan (NYSE:AGN) in a cash-and-stock transaction valued at $63 billion; this transaction is set to close this May.

Thanks to this acquisition, AbbVie should be able to expand its lineup as well as its pipeline. In particular, the company will now have access to Botox, a product for which we are unlikely to see biosimilars anytime soon, at least according to AbbVie CEO Richard A. Gonzalez. Given all these factors, AbbVie could keep growing its revenue at a nice clip. 

ABBV Dividend Yield Chart

ABBV Dividend Yield data by YCharts

AbbVie's dividend yield is currently 6.18%, and the company has raised its dividends by 195% since it was created in 2013. AbbVie is also trading at just 7.2 times future earnings. Now might be as good a time as ever to purchase shares of this top dividend stock.

2. Pfizer 

Pfizer went through some critical changes last year. For instance, the company formed a joint venture with GlaxoSmithKline (NYSE:GSK), called GSK Consumer Healthcare, which combined both companies' consumer healthcare segments; Pfizer owns a 32% stake in this venture. The transaction officially closed in August 2019.

In July 2019, Pfizer also announced it would merge Upjohn, its "off-patent branded and generic established medicines business," with Mylan (NASDAQ:MYL) to create a new company called Viatris. Given the terms of the merger, Pfizer's shareholders will hold a 57% stake in Viatris; this transaction is set to close in mid-2020. Pfizer decided to make these moves in part because its Upjohn unit and its consumer healthcare segment had been underperforming. 

For instance, during the fourth quarter, the company recorded revenue of $12.7 billion, representing an 8% year-over-year decline. However, when the effects of its consumer healthcare business are excluded, the company's revenue increased by 1% year over year. Furthermore, Pfizer's Upjohn unit posted $2.2 billion in revenue during the fourth quarter, a 32% year-over-year decrease. The company's biopharma business, on the other hand, recorded a revenue of $10.5 billion during the quarter, a 9% increase compared to the prior-year quarter.

Pfizer will be able to focus on its biopharma business moving forward, and the pharma giant has several exciting products in its lineup that will likely drive decent sales growth in the future. For instance, its anticoagulant, Eliquis, reported sales of $4.2 billion in 2019, representing a 26% increase compared with fiscal 2018. And sales of cancer drug Ibrance were $4.96 million in 2019, 23% higher than the previous fiscal year.

Pfizer boasts other products with fast-growing sales, including rheumatoid arthritis drug Xeljanz, whose sales increased by 29% year over year to $2.2 billion in 2019. Eliquis and Ibrance deserve special mention, though: According to the research firm Evaluate Pharma, both of these products will be among the 10 best-selling drugs in the world by 2022.

Pfizer also boasts several interesting pipeline products. Notably, the company acquired Array BioPharma -- a company that focuses on the development of cancer treatments -- in an all-cash transaction valued at $11.4 billion that closed in July of 2019. 

Thanks to this acquisition, Pfizer acquired the rights to Braftovi and Mektovi; the combined use of these two products is approved for the treatment of metastatic melanoma, a form of skin cancer. Braftovi and Mektovi are currently being investigated as a combination treatment for many other types of cancer in more than 30 clinical trials. As CEO of Pfizer Albert Bourla said when the company first announced the acquisition:

The proposed acquisition of Array strengthens our innovative biopharmaceutical business, is expected to enhance its long-term growth trajectory, and sets the stage to create a potentially industry-leading franchise for colorectal cancer alongside Pfizer's existing expertise in breast and prostate cancers.

Lastly, Pfizer is currently attractively valued.

PFE Dividend Yield Chart

PFE Dividend Yield data by YCharts

The company's dividend yield is 5.1%, well above the S&P's average yield of 2%, and Pfizer has raised its dividends by 35.7% over the past five years (not to mention that it's paid a dividend every year since 1980). Investors looking for attractive dividend-paying stocks would do well to buy shares of Pfizer.