THE VACCINES AND ANTIBODIES

Scientists at the National Institute of Allergy and Infectious Disease's Vaccine Research Center and labs around the world are racing to develop and test vaccines. Unfortunately, even if the current vaccines under study are successful, they could take many months before hitting the clinics. One vaccine in development is called mRNA-1273 and is based on prior studies on coronaviruses such as the original SARS and MERS. As with most vaccines, mRNA-1273's job is to stimulate a person's body to produce antibodies that will neutralize SARS-CoV-2 by attacking its surface spikes. The spikes bind the virus to human cells, allowing the virus to gain entry. Neutralizing antibodies block that interaction. The hope is that by eliciting neutralizing antibodies, mRNA-1273 will prevent the virus from latching on to cells. Another fight against COVID-19 is underway using plasma (blood with its cells removed) from patients who have recovered. The theory is that antibodies against the virus in a recovered person's blood may help those with severe cases. While this type of “passive immunization” originated more than 100 years ago, the type of transfusion for COVID-19 has only been studied in a very small sample around the world.

Vaccine basics

Here, SARS-CoV-2 attaches to cells via its spike proteins, causing cellular infection and destruction. The aim is for the body to produce antibodies (dark balls) that will bind to the virus's surface spikes and prevent them from latching on to healthy cells. Bound antibodies also mark the virus for destruction by the body's immune system.