Moderna’s Vaccine Efficacy Readout

As expected, we have more vaccine news this morning. And the news is good. Moderna reports that their own mRNA candidate is >94% effective (point estimate), with 95 total cases in the trial to date, split 90/5 between the control group and the vaccinated group. 11 of those were severe infections: all 11 in the controls and zero in the vaccine patients. Of the 95 total cases, 15 were in participants 65 years and older, but there’s no word on the split between controls and the vaccine arm there. All of these points are at 14 days past the second dose of the vaccine, which is going to be a standard time point for all the trials (except the J&J one-dose candidate, of course).

The safety readout looks like what we were expecting as well: the Grade 3 events were fatigue in 9.7% of patients, myalgia (muscle pain) in 8.9%, arthralgia (joint pain) in 5.2%, headache in 4.5%, and just “pain” in 4.1%. I would assume that there is overlap in these categories. The company says that these were “generally short lived”. The FDA’s guidance on event reporting would class these as “significant, prevents daily activity”, but not requiring hospitalization. So my read now with the data we have is that up to 10% of people taking the shot will spend the next day or so in bed, feeling like they’ve been hit with a really bad flu. That’s not enjoyable, but I will definitely make that trade in exchange for coronavirus immunity (see below). More data are being collected, of course, so we’ll get better reads on both safety and efficacy as the trial goes on, as will be the case with the Pfizer candidate and the others as well. We have to make sure (as much as we can) that there aren’t worse effects poking up out of those Grade 3 events, but so far, so good.

The second press release from the company today is also significant: Moderna says that new stability testing shows that their vaccine remains stable for up to six months under standard freezer conditions, up to 30 days under standard refrigeration conditions, and up to 12 hours at room temperature. There’s no dilution or further handling at the point of administration. This is much more like what you want to see, as compared to the more demanding storage conditions that seem to be needed for the Pfizer candidate. This is how a lot of medicine (and food, for that matter) is already distributed and stored – our infrastructure is a lot more prepared for this.

So we’re already starting to see some differentiation between the candidates, with likely more to come. We’ll see if there’s any statistical daylight in efficacy between the Pfizer and Moderna candidates as more cases accrue (I have no idea if that’ll be the case or not). Likewise with safety. But we already have a difference in shipping and storage, and it’s in Moderna’s favor. As mentioned before here, there are several other categories that could differentiate all the vaccine candidates: point efficacy (as we have now, 14 days after the second), effect on severity of disease when it does occur, duration of efficacy (which we’ll need time for, and there’s no other way), overall safety (which also needs big numbers and will sharpen with longer time points), and whatever differences in all these categories may show up in different patient populations. Those will take time to emerge, too, most likely,

But make no mistake: right now the vaccine news is very good indeed. Effective ones are coming, and what I said when the Pfizer results came about applies even more now, because this good news is coming against a stark background. The coronavirus statistics here in the US now are very, very bad, with cases, hospitalizations, and deaths all rising. Many areas of the country are facing ICU capacity shortages as we head into these rising numbers, and in the coming weeks a lot of people are going to die. It’s never been more important for people to take action against the pandemic: isolation as much as possible, mask wearing, avoiding indoor groups, and all that stuff that we already know about but that apparently too few people are following through on. The curves from Europe have been accelerating at a similar alarming rate, but take a look: their case numbers starting to turn back down again, and there’s no reason we can’t do that here. And we’re not going to be doing all this forever; I really think that the vaccine results we’re seeing mean that the end of all this is finally in sight. We have to make it through to getting our population vaccinated. Hang on.