Clinical-stage immunotherapy company, ImmunityBio, Inc. IBRX, reported encouraging initial data on its COVID-19 vaccine candidate.The data demonstrated that a single subcutaneous injection of the company’s COVID-19 vaccine candidate in healthy phase I study participants stimulates the generation of T cells that are reactive to the spike (S) and nucleocapsid (N) protein antigens delivered by the vaccine.The magnitude of this T cell response was equivalent to those seen for S & N T cell responses from previously infected convalescent SARS-CoV-2 patients. The mean level of T cells generated in response to the hAd5 S+N T cell vaccine was ten times higher for N-specific T cells just 14-16 days after the single dose. By day 21, both S and N T cell responses achieved levels ten times higher as compared to pre-vaccination levels.Per the company, these findings provide the potential of the hAd5 S + N T cell vaccine for use as a "Universal T Cell Booster" to enhance T cell immunity in healthy recipients of current vaccines or previously infected convalescent subjects.The phase Ib study is ongoing to explore the safety and immunogenicity of subcutaneous, oral and sublingual prime-boost combinations of the hAd5 S + N vaccine. The company’s shares have surged 143.7% in the year so far against the industry's decline of 6.5%. The emerging variants of SARS-CoV-2 pose a significant threat as authorized vaccines face challenges.Per the company, current vaccines target the S protein, leaving open the potential for antigen drift (mutation) and rendering these vaccines to be less effective against variants. ImmunityBio aims to develop the second-generation COVID-19 vaccine, which is room-temperature stable, can be self-administered orally and generates both antibody and long-term T cell immunity.The FDA has already granted Emergency Use Authorization (EUA) to Pfizer PFE/BioNTech and Moderna’s MRNA vaccines for COVID-19. Last month, the FDA granted EUA to Johnson & Johnson’s JNJ single-dose COVID-19 vaccine in individuals 18 years of age and older.ImmunityBio currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.Zacks Names “Single Best Pick to Double”From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all.You know this company from its past glory days, but few would expect that it’s poised for a monster turnaround. Fresh from a successful repositioning and flush with A-list celeb endorsements, it could rival or surpass other recent Zacks’ Stocks Set to Double like Boston Beer Company which shot up +143.0% in a little more than 9 months and Nvidia which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Johnson & Johnson (JNJ): Get Free Report Pfizer Inc. (PFE): Get Free Report Moderna, Inc. (MRNA): Get Free Report ImmunityBio, Inc. (IBRX): Get Free Report To read this article on Zacks.com click here. Zacks Investment Research