Pfizer (PFE) is one of the largest pharmaceutical companies by market assessment.  Pfizer shares may soon experience an upswing after signing a Coronavirus vaccine development agreement with BioNTech (BNTX). The two companies signed a partnership agreement on March 17 to develop a vaccine aimed at eliminating Covid-19. Respiratory disease was detected last year in China. Under the terms of the deal, Pfizer and BioNTech will work together on the drug outside China. There was a lot of news about Pfizer's merger. Last summer, the Dow Jones component acquired Array Biopharma for $11.4 billion. There are also plans to merge generic and off-patent drugs known as Upjohn with Mylan (MYL) in 2020. In May 2019, the pharmaceutical company also received approval from the Food and Drug Administration to sell a rare heart medicine. But more recently, in April 2020, the total first-quarter revenue and sales fell. As one of the largest pharmaceutical companies, Pfizer is well diversified. But Pfizer's sales are dropping. First-quarter sales fell 8% to $12.03 billion, continuing a four-quarter downward trend. Revenue also fell 6 percent to 80 cents per share, falling for the third consecutive quarter. In the first quarter ended March 29, Pfizer reported $231 million in sales of Vyndaqel and Vyndamax, a pair of drugs used to treat a disease that builds protein in the heart. According to one of the analysts, it was estimated at $233 million. But the total volume of sales and revenues are declining, drawing a dull picture. Large institutional investors, which account for up to 70% of all market trades, tend to look for shares with accelerating revenues and increasing sales. Besides, the pharmaceutical company does not follow the CAN SLIM investment rules, which tell investors to look for shares with an annual increase in earnings per share of at least 25%. Investors should also keep an eye on stocks with 20-25% sales growth in the last quarter. In the second quarter, analysts surveyed by Zacks Investment Research urged Pfizer to reduce adjusted earnings by 25% to 60 cents per share. According to other estimates, adjusted earnings this quarter will be 68 cents per share, which means a 15% drop. Pfizer sales are expected to decline by 12% to $11.67 billion. On March 17, Pfizer shares rose by almost 7% after the pharmaceutical company said it would code coronavirus vaccine with BioNTech. The deal is focused on areas outside China, where BioNTech is already working with Shanghai Fosun Pharmaceutical Group. The vaccine will prevent SARS-CoV-2 infection. It is based on a natural substance in an organism called messenger RNA. The messenger's RNA carries the genetic code to create proteins. Modern (mRNA) also tests the coronavirus vaccine using the same technology. On May 5 companies Pfizer and BioNTech have tested the first participants of research. Also, in the first quarter, sales of drugs from Pfizer, designed to treat rare diseases, rose by 36% to 639 million dollars. Overall, this segment accounted for only 5.3% of Pfizer's total revenue. Pfizer added to this portfolio last May when it was approved by Vyndaqel and Vyndamax. Both represent different doses of the same product, a rare disease in which a protein called amyloid builds up in the heart. They brought in 231 million dollars in the first quarter. Vyndaqel and Vyndamax can compete with Alnylam Pharmaceuticals (ALNY) and Ionis Pharmaceuticals (IONS). Medicines from biotechnology treat the nerve components of the same disease. But there is some coincidence in patients who have nerve and heart complications. In mid-February, the European Commission also approved Vyndaqel