COVID Transmissions for 3-31-2021

Updated data for two vaccines

Greetings from an undisclosed location in my new apartment. Good morning and welcome to COVID Transmissions.

It has been 499 days since the first documented human case of COVID-19. In 499, Emperor Xiaowen of Northern Wei China died at the age of 31 after reigning from the age of 4. He died during a military campaign, after rooting out a serious palace intrigue.

I am thinking of Emperor Xiaowen as I aggressively isolate before getting my vaccine today. I imagine that in retrospect, he might have preferred to stay home too.

Today I wanted to update you on some vaccine data for Novavax and AstraZeneca, both of which we’ve discussed before but have had some new developments.

As usual, bolded terms are linked to the running newsletter glossary.

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Now, let’s talk COVID.

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Novavax vaccine

Carl Fink reminded me we have some new vaccine data! I meant to cover these, but they came out in the lead-up to my move.

I covered earlier results for the Novavax vaccine (a nanoparticle vaccine with a recombinant protein on the surface) in January when they came out, but they were a little more mixed at that time: https://covidtransmissions.substack.com/p/covid-transmissions-for-1-28-2021

That analysis has now matured, and final results are available. Those final results update the picture a little bit. Healio has a story on it here: https://www.healio.com/news/infectious-disease/20210312/final-analysis-shows-novavax-covid19-vaccine-100-protective-against-severe-disease

These results do not really move the needle much for this vaccine. Previously, efficacy in the UK was 89.3% and here it is 89.7% overall.

However, we do see some granularity in the results with respect to the B.1.1.7 variant versus the other lineages.

Note: the Healio article calls older lineages “wild-type,” which I’ve seen people do, but I don’t think it’s very good terminology. Wild-type (WT) is used in laboratory studies to refer to and unmodified organism in genetic studies. WT is usually used as a control. In this case, all lineages of SARS-CoV-2 are WT lineages. They all occur naturally in the wild and none are the result of laboratory manipulation. So I don’t think use of “WT” is appropriate. I prefer “ancestral lineages” or “older lineages,” but I have to confess I don’t have a clear term for what one might call the “OG” SARS-CoV-2 versus the newer variants. I’ve seen some folks call it the “Wuhan lineage,” but there are a lot of problems with using geographical terms. I’ll stick with my ad-hoc terminology.

Now, back to the results. With the ancestral lineage infections, the Novavax vaccine was about 96.4% effective in preventing any disease. With B.1.1.7, this was instead about 86.3%. But keep in mind that both of these assessments are estimates based on an experimental trial; in the real world the results will be different. I am encouraged that the numbers here are all above 85%.

There’s still the separate matter of data from the B.1.351 variant, where in a Phase 2b trial, the efficacy of the Novavax option appeared to be much lower. I am hoping that we will hear more about that soon, because based on the final analysis of that study, the Novavax vaccine is only 55.4% effective against that particular variant.

That’s concerning, but there’s some good news: the vaccine was 100% effective in both trials against severe disease. So while we need to keep an eye on these variants, particularly B.1.351, Novavax’s product looks like it could soon be another authorized option that will effectively reduce the most harmful impacts of COVID-19.

AstraZeneca vaccine data update

Last week, I really tore into AstraZeneca for releasing data from an unfinished analysis when they were just days away from having the final analysis.

Well, shortly after that, they released the updated data. This update included 49 more cases of COVID-19 in all trial arms, and the overall vaccine efficacy was about 76%, where they had originally reported 79%.

This is just such an amateurish situation, I’m really still rather upset about it. They should have done things substantially more professionally here.

That said, the vaccine still appears to work. The safety profile appears generally well-tolerated. If AstraZeneca would stop with these unforced errors, I think they could get to a place where the FDA might authorize their vaccine for use in the US, since the vaccine is already in successful use in other places around the world.

You can read more details on the new results at Science News: https://www.sciencenews.org/article/covid-coronavirus-astrazeneca-vaccine-data-update-efficacy

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What am I doing to cope with the pandemic? This:

Getting my vaccine!

Today I will be getting the first dose of my Pfizer vaccine. I chose Pfizer over the Johnson & Johnson option (I only had two options) because I wanted more confidence that there is an effect on my ability to transmit the virus to others. There is solid data from Israel that has convinced me that the Pfizer vaccine not only protects me, but protects the people around me. I want that effect.

That said, I think all the vaccines that are currently authorized in the US probably have this effect. I don’t think there’s a big, meaningful difference between them here. I just went with the one that I know has the data right now.

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Though I can’t correct the emailed version after it has been sent, I do update the online post of the newsletter every time a mistake is brought to my attention.

No corrections since last issue.

See you all next time.

Always,

JS