The immune system responds to the protein by forming what are known as neutralizing antibodies. The mRNA is wrapped in a lipid nanoparticle that protects it from breaking down. To make the new vaccines, scientists at Pfizer and Moderna set about using a genetic tool called messenger RNA, or mRNA, to induce the body to produce the spike protein-without the rest of the virus cell that actually makes people sick. "It's the difference between making macaroni and cheese from a blue box that you pick up at the grocery store, where someone's already refined all of the ingredients and made it easy for you, versus starting with a cow and a sheaf of wheat," Landon said. ![]() Scientists then quickly identified the best target for a vaccine: a spike protein that pierces cells to allow the virus to start multiplying in the body. So after the novel coronavirus emerged in China late in 2019, researchers there were able to swiftly decipher the genetic blueprint for SARS-CoV-2. Only then can the virus-based vaccine be tested on animals and then in human trials.īut scientists have long been working to develop new kinds of vaccines that skip the first part of the process by using genetic technology to create an immune response.ĭecades of research had already given scientists the ability to map the genome-the genetic coding-of a virus. Making them is time-consuming because scientists must learn how to grow the virus and render it harmless without destabilizing it. Traditional vaccines are based on a weakened version of the virus that triggers an immune response without causing illness. It typically takes years to develop a new vaccine. They obviously work."ĭozens of other vaccines now are being tested, with a Johnson & Johnson version given emergency use approval in late February. I just thought they weren't going to work. "I didn't think they were going to be unsafe. Emily Landon, executive medical director of infection prevention and control at University of Chicago Medicine. "I thought they weren't going to work," said Dr. Testing had showed each to be more than 90% effective-far better than earlier expectations-with side effects no worse than many other successful vaccines. Before the year was out, vaccines from Pfizer and Moderna had been granted emergency use authorization by the U.S. ![]() Other experts expressed skepticism, given the difficulties encountered when trying to develop vaccines for other viruses and the novel genetic technologies being used to develop COVID-19 vaccines.īut vaccine makers defied the skeptics, not once but twice. Anthony Fauci-considered the nation's leading infectious disease expert-said it was possible we could have a safe and effective vaccine by the end of 2020. Last May, just two months into the pandemic, Dr. Here's a summary of some of the knowledge we've gained, and what we still hope to learn. But even those optimists concede they are worried about the virus's evolution and the possibility it will "learn" to evade the immune responses already triggered by infection or inoculation. Many public health experts believe the light at the end of the tunnel is real, if the world remains vigilant about taking precautions, tracking cases and getting vaccines into arms. Some of that new knowledge inspires hope, even as other emerging facts continued to fuel apprehension amid growing pandemic fatigue. ![]() Since then, we've learned a great deal more. ![]() People started tossing around terms such as airborne particles, social distancing and superspreaders. Just six months into the pandemic, there was much we all learned, as scientists across the world turned their focus to the disease and shared their discoveries. But a prolonged global threat to commerce, lifestyles and millions of human lives has a way of focusing minds.
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