Houston Methodist expert to speak on J&J COVID vaccine:

H. Dirk Sostman, M.D., president of the Houston Methodist Academic Institute

He can discuss how the J&J vaccine, like the Pfizer and Moderna vaccines, works by inducing your own cells to produce the coronavirus’s “spike” protein (the part of the virus that latches on to your cells).  It does it in a slightly different way.  First, instead of using messenger RNA to deliver the instructions, it uses a DNA construct that then produces the RNA within your cells.  Second, instead of a completely artificial lipid nanoparticle  (Pfizer and Moderna), &J uses a harmless adenovirus as the carrier.  So the J&J vaccine is slightly more complicated but does essentially the same job as the Pfizer and Moderna vaccines.

Dr. Sostman can also discuss how the J&J vaccine appears to be similar in its ability to prevent severe COVID illness. It may be slightly less potent overall at producing high levels of protective antibodies and thus may not prevent as many mild-to-moderate cases.  It still looks like it will be a very effective and useful vaccine.  For comparison, the seasonal flu vaccine is about 50% effective.