We still don’t know how well a robust immune response protects people from SARS-CoV-2 infection. But we’ve got a further indication that vaccines can induce a strong immune response. Just prior to the holiday weekend, a Chinese team released the results of a safety trial done using a harmless virus that had been modified to carry one of the coronavirus genes. While there were a number of side effects, everyone getting the vaccine had a robust antibody response, including some antibodies that neutralized the virus.

Familiar virus, new protein

The first indication of progress toward a vaccine that we’re aware of came in the form of a company press release. This new one comes in the form of a peer-reviewed article in the prestigious medical journal The Lancet. Most of its authors are academic researchers or public health authorities; only two have affiliations with a company.

The two reports also differ significantly in terms of their approach to generating an immune response. The earlier announcement, from a company called Moderna, involved injecting carefully packed RNAs that encode the spike protein that normally resides on the surface of the virus. The RNAs transit inside a person’s cells and induce them to produce the spike protein, thereby exposing the immune system to it.