Scientists and Wall Street analysts are now beginning to peal the onion of Moderna’s announcement about its Phase One Trial results in which it reported its vaccine candidate had produced antibodies in eight of the study’s 45 participants. Following the announcement, Moderna’s shares rose nearly 30%. A profitable day, indeed.
On Tuesday, I wrote it was way too early to get excited based on this teeny tiny study. Since then, it’s nice to see that Evercore ISI’s Umer Raffat, an analyist Institutional Investor called a Rising Star of Wall Street Research, has added context and perspective. Early Tuesday, Raffat sent a 78-page slide deck to his clients explaining why, while possibly encouraging, Moderna’s announcement and Monday conference call should not give anyone a serious sense of hope until a lot more work is done and a lot more is known about this particular Phase One Trial.
Getting into the science weeds, Raffat focused his analysis on antibodies and T-Cells.
First, the antibodies. Raffat thinks the most impressive thing about Moderna’s data release concerns “binding” antibodies. These are antibodies that attach to SARS-CoV-2, the virus that causes COVID-19. The concern with Moderna’s announcement is that what’s really important for an effective vaccine is its ability to generate “neutralizing” antibodies that actually prevent the virus from infecting healthy cells, and Moderna provided no information about neutralizing antibodies except to say its neutralizing antibodies “were at or above convalescent serum” collected from people who recovered from COVID-19. Studies have shown that people who have recovered from COVID-19 can generate a wide range of neutralizing-antibodies in their convalescent serum. So, it is unclear just how comparable Moderna’s convalescent serum samples were to samples taken from the trial participants.
The FDA will have to determine what level of neutralizing antibodies are required for an approved vaccine. The Agency has already said that when convalescent serum is used to treat COVID-19 patients the neutralizing antibodies should be high, whatever that means.
Another issue with Moderna’s mRNA-1273 vaccine rests with T-Cells. The level of T-Cell generation is an indicator of the degree to which the immune system is attacking COVID-19. Moderna’s announcement and subsequent call did not address this. Some researchers have shown that a high level of T-Cell generation, even without high levels of neutralizing antibodies, have been found in people who have recovered from COVID-19, leading to speculation that T-Cell generation may be very important for any successful vaccine. However, when asked about this during the conference call, Moderna’s Chief Medical Officer, Tal Zaks, M.D., Ph.D., said “You would expect that based on the fundamental scientific principles of how an mRNA vaccine works because it teaches the body’s own cells to make the protein from within the cell.”
One last point – The study participants numbered 45. Eight produced binding antibodies. Only four were sampled for neutralizing antibodies. Four.
As I wrote earlier this week, Moderna has made it to the one yard line. Ninety-nine to go.
Tags: vaccine
