Vaccine table updated

In an effort to keep you up to speed.

Lots of vaccine updates, so I updated the table.

Here is a brief summary explaining the changes (and data sources):


  • In a press release yesterday, Pfizer gave us a glimpse of their clinical trial 6 month data!! Super exciting. And it looks absolutely beautiful.

    • 12,000 people now have 6 months of data

    • Efficacy is 91.3% (927 COVID19 cases popped up: 850 cases in the placebo group and 77 cases in the vaccine group)

    • No impact on B.1.351 (S. Africa) efficacy. However, this was a really small sample size, so we aren’t too confident in these numbers. But a good sign.

    • Prevented 100% of severe disease on old variants and S. Africa variant

  • 100% efficacy found in the adolescent trial (previous post here)

  • Still works against lots of variants, thanks to T-cells

  • FDA approved warmer storage


  • Phase I for a vaccine booster against B.1.351 (booster against the S. African variant) has started

  • Still works against lots of variants, thanks to T-cells


  • Efficacy remains high (75%) against B.1.1.7

Brazil variant

  • We are starting to learn a lot about P.1/P.2 (which originally detected in Brazil). It looks like it’s acting a lot like B.1.351 (originally detected in S. Africa). This makes sense because a lot of the mutations are the same. We have some data from J&J trial. For mRNA vaccines, we now know that they will still work against P.1 because of T-cells.

Frequently Asked Table Questions

  1. Efficacy vs. neutralizing antibodies? There are two ways to measure how well a vaccine works: Efficacy and immunogenicity. Immunogenicity is a more complicated metric that measures the type of immune responses that the vaccine generates and their magnitude over time. Unfortunately, there is currently no definitive set values that “define” a protective immune response (we are still working on this). So, we just know that immunogenicity is “lower” against variants, but we don’t really know what that exactly means in terms of efficacy. Also, there are a lot of different lab studies to measure immunogenicity. So, we can’t compare neutralizing antibodies from one study (like among Moderna) compared to another study (like for Pfizer).

  2. Why is there more Pfizer press than Moderna? I don’t know, but I can make conjectures. Pfizer is a seasoned, big fish in this game. This is Moderna’s first vaccine. Less press is not reason to worry about Moderna. The biotechnology is almost exactly the same, so there’s no reason to think that Moderna is meaningfully different than Pfizer.

Other Random Update

  • Vaccine hesitancy continues to decrease in the United States! We still have work to do, though.

Love, YLE