What happened
Shares of biopharmaceutical company Emergent BioSolutions (EBS 1.24%) gained 46.6% in the first half of 2020 (January to June), according to data from S&P Global Market Intelligence. The S&P 500 returned negative 3.1% over the period.
In 2020, the stock is up 55.9% through Thursday, July 2, while the S&P 500 has returned negative 2.1%.

Image source: Getty Images.
So what
Emergent has quite a few irons in the fire, as it has a portfolio of commercialized products and a solid pipeline. The company specializes in developing and manufacturing vaccines and therapeutics that target infectious diseases and biological and chemical agents.
However, we can attribute Emergent stock's robust first-half 2020 performance to its COVID-19 vaccine contract development and manufacturing deals. A handful of companies that are developing COVID-19 vaccine candidates have signed agreements with Emergent to be their U.S. manufacturing partner.
Data by YCharts.
Notable among these are pharma giants Johnson & Johnson (JNJ) and AstraZeneca (AZN 0.38%), which inked approximately $135 million and $87 million deals, respectively, with Emergent. Biotechs Novavax (NVAX 0.67%) and Vaxart (VXRT 5.31%) have also signed manufacturing agreements with the company.
The Novavax and Vaxart deals occurred in March, followed by the J&J and AstraZeneca deals in April and June, respectively.
In addition, in March, Emergent began developing two plasma-derived product candidates for the treatment and prevention of COVID-19. These candidates are being developed on the company's hyperimmune platform.
Now what
Emergent BioSolutions isn't profitable. In the first quarter, it recorded a net loss of $12.5 million and an adjusted net loss of $0.3 million.
However, investors who are comfortable with that fact might find it an appealing way to get exposure to the COVID-19 vaccine space. Buying the stock essentially spreads your bet among several companies in the race to develop a vaccine.