Vaccines!

As everyone heard, Pfizer announced preliminary results. As a safety requirement, clinical trials are required to periodically present interim data to an external oversight committee (I’ve posted about this committee before). This process is important in order to check futility. Basically, safety checks ensure that the study can complete what was promised and results are promising. If not, the trial will be stopped for the sake of participants. So, today’s announcement was routine. But (and this is important), the data are not published nor is the trial over.

During the meeting, Pfizer reported a 90% vaccine effectiveness, as 94 volunteers who got the vaccine developed COVID19 (more than half of the 164 needed to complete the trial). Unfortunately, we don’t know how many did NOT develop COVID19, but it must be a lot (the trial plans to enroll 44,000 volunteers). IF 90% holds for another month of data collection, we will be in insanely great shape. This is much higher than the effectiveness of a flu shot and close to the effectiveness of the measles vaccine. Most scientists were hoping for at least 55-60% effectiveness.

Why is this good news? Two reasons…

On a practical level, the effectiveness of a vaccine campaign (ie reaching herd immunity) is dependent on two things: effectiveness and uptake. Ideally, both would be 100% but we know that’s not possible. In August, scientists published that, during an ONGOING pandemic and in the absence of other interventions, we need a COVID19 vaccine with at least 80% efficacy and 75% coverage. However, we are seeing vaccine hesitancy. With a higher than expected effectiveness, this could make up for lower than expected uptake.

On a scientific level, this would be gigantic leap in vaccine development. Pfizer is using a new approach (same as Moderna): an mRNA vaccine. This vaccine implants instructions into cells on how to destroy COVID19. This is a new approach and has never been accepted by the FDA. If it does, this will be a big leap in science. Typically a vaccine is part of (or a whole) live virus that engages the immune system. If a mRNA vaccine is approved, the next BIG hurdle is distribution. This vaccine must be kept in ultracold temperatures. Pzier has developed a way to transfer these vaccines, but storage and where the vaccine will be logicially distributed is another story.

Nonetheless, I’m, again, cautiously optimistic with this news. We should know a whole lot more from this trial (and others) in the upcoming month. Maybe we will all get an early holiday gift.

Love, YLE

For data sources, search my blog (www.yourlocalepidemiologist) for “vaccine” or “data safety” for previous posts and all data sources.