How Big Of A Deal Is mRNA Vaccine Efficacy? Imagine If It Had Failed

Pfizer (PFE 2.40%) and its German partner BioNTech (BNTX 0.74%) reported incredible efficacy data from a phase 3 trial for their mRNA coronavirus vaccine candidate. This news, paired with the equally impressive data from Moderna (MRNA -0.58%) about its candidate that takes a similar approach, inspired much hope around the world and injected optimism into the stock market.

The Motley Fool sat down with Dr. Jeremy Brown, author of Influenza: The Hundred-Year Hunt To Cure The Deadliest Disease In History and Director of Emergency Care Research at the National Institutes of Health. Dr. Brown shared what these exciting developments mean for the world and for investors.

Cardina: Let's start with the big news on Monday that everybody is talking about. We have Pfizer and BioNTech released a press release on Monday, gave the public new information about their COVID-19 vaccine candidate. An important thing to know is that this data has not yet been peer reviewed and we do not have the raw data. This was a summary in a press release, but a lot of experts are heralding this as proof of concept for vaccines that taken mRNA approach which is new. It's never been on the market before. Right now, the early data indicates that the efficacy, meaning that it accomplishes its goal of preventing COVID-19 is more than 90%. For context, the FDA had said 50% would be good enough to license. Dr. Brown, can you tell us a little bit more about what this really means? How encouraged are you by this new information?

Brown: Well, this is really a wonderful piece of good news that everybody I think is happy about. Imagine if the news would come out that it had failed, that would be awful for the prospects of a vaccine soon. But this news, even though it is preliminary, as you said, is exciting and it's optimistic. We do have to be careful as you pointed out, and as others have pointed out that, this is a preliminary press release which is not in any way a scientific review of what happened. Just to give people a context in this large study involving, I think over 30,000 or 40,000 people, the groups are split into two. Half the people got the Pfizer vaccine and the other half got a placebo, which is an inert equivalent if you like, a substance that is injected but is not actually the vaccine. They waited to see what would happen in a natural way to the people in the groups. How many in each group would actually come down with COVID. As you said, a success rate of over 50% reduction would have been meaningful to go ahead and actually produced this for everybody. but the results so far are that it is 90% effective. What we don't know is the following, is it 90% effective in all age groups and especially in the elderly? As we know, their immune systems often are a little bit harder to get energized and they sometimes actually they quite frequently require different kinds of vaccinations than the younger people. We don't know if it helps, specifically people in that age group. We also not sure of course, about people in specific with underlying medical conditions, whether it helped people in those age groups. Although, it certainly should. So good news all round and we'll have to wait and see.