Shares of Abbott Laboratories /zigman2/quotes/203724446/composite ABT -0.43% were down 0.8% in premarket trading on Wednesday. The company beat expectations for both earnings and revenue in the fourth quarter, bolstered by more than $2 billion in sales of its COVID-19 tests during the quarter's omicron surge. Abbott had earnings of $1.9 billion, or $1.11 per share, in the fourth quarter of 2021, compared with earnings of $2.1 billion, or $1.20 per share, in the same quarter in 2020. Adjusted earnings per share were $1.32, which is higher than the FactSet consensus of $1.21. Abbott reported revenue of $11.4 billion for the fourth quarter of 2021, up from the $10.7 billion in reported in the final quarter of 2020. The FactSet consensus was $10.7 billion. This was driven in part by $4.4 billion in sales in its diagnostics business, including the $2.3 billion that came from sales of its COVID-19 tests during the final three months of the year. The company said it expects to generate $2.5 billion in sales of COVID-19 tests in 2022, with those sales likely happening early in the year. It also said it expects adjusted EPS of $4.70 in 2022. "We see our guidance as a prudent starting point, given the unpredictability of the virus and variants," a spokesperson said in an email. Abbott's stock is down 12.4% so far this year; the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.29% has declined 8.6%.