The pathogen at the center of the outbreak, SARS-CoV-2, belongs to the family of viruses known as coronaviruses. This family is so named because, under a microscope, they appear with crownlike projections on their surface.

In developing a vaccine that targets SARS-CoV-2, scientists are looking at these projections intensely. The projections enable the virus to enter human cells where it can replicate and make copies of itself. They’re known as “spike proteins” or “S” proteins. Researchers have been able to map the projections in 3D, and research suggests they could be a viable antigen in any coronavirus vaccine.

That’s because the S protein is prevalent in coronaviruses we’ve battled in the past — including the one that caused the SARS outbreak in China in 2002-03. This has given researchers a head start on building vaccines against part of the S protein and, using animal models, they’ve demonstrated they can generate an immune response.

There are many companies across the world working on a SARS-CoV-2 vaccine, developing different ways to stimulate the immune system. Some of the most talked about approaches are those using a relatively novel type of vaccine known as a “nucleic acid vaccine.” These vaccines are essentially programmable, containing a small piece of genetic code to act as the antigen.

Biotech companies like Moderna have been able to generate new vaccine designs against SARS-CoV-2 rapidly by taking a piece of the genetic code for the S protein and fusing it with fatty nanoparticles that can be injected into the body. Imperial College London is designing a similar vaccine using coronavirus RNA — its genetic code. Pennsylvania biotech company Inovio is generating strands of DNA it hopes will stimulate an immune response. Although these kinds of vaccines can be created quickly, none have been brought to market yet.

Johnson & Johnson and French pharmaceutical giant Sanofi are both working with the US Biomedical Advanced Research and Development Authority to develop vaccines of their own. Sanofi’s plan is to mix coronavirus DNA with genetic material from a harmless virus, whereas Johnson & Johnson will attempt to deactivate SARS-CoV-2, essentially switching off its ability to cause illness while ensuring it still stimulates the immune system.

On March 30, Johnson & Johnson said human tests of its experimental vaccine will begin by September. “we have a candidate that has a high degree of probability of being successful against the covid-19 virus,” said Alex Gorsky, CEO of Johnson & Johnson, during an interview with NBC News’ Today. “”Literally within the next few days and weeks, we’re going to start ramping up production of these vaccines.”

DIOSynVax, a vaccine development company working out of the University of Cambridge, is trying to eschew the traditional pathways to vaccine creation with a new platform. The company’s approach uses computer modelling of the virus’s structure to determine weak spots in the SARS-CoV-2 DNA — places it can target to drive an immune reaction without causing any harm to the patient. “What we end up with is a mimic, a mirror image of part of the virus, but minus its bad parts,” said Jonathan Heeney, CEO and founder of DIOSynVax, in a statement. “What remains is just the magic bullet, essentially, to trigger the right type of immune response.”

Some research organizations, such as Boston Children’s Hospital, are examining different kinds of adjuvants that will help amplify the immune response. This approach, according to the Harvard Gazette, will be targeted more toward the elderly, who don’t respond as effectively when vaccinated. It’s hoped that by studying adjuvants to boost a vaccine, the elderly can be vaccinated with a mix of ingredients that would supercharge their immunity.