COVID Transmissions for 1-21-21
One vaccine dose is apparently not enough
Good morning and welcome to COVID Transmissions.
It has been 430 days since the first documented human case of COVID-19.
Yesterday, a new President was inaugurated in the US, and I have heard he has some aggressive plans to control COVID-19. I'm eager to see what they are and how they work.
Today, in this newsletter, we have some headlines about the current situation followed by—unusually—a long Pandemic Life section. In it, I imagine when we might start to see things return to something like “normal.”
As usual, bolded terms are linked to the running newsletter glossary.
Keep the newsletter growing by sharing it! I love talking about science and explaining important concepts in human health, but I rely on all of you to grow the audience for this:
Now, let’s talk COVID.
A new variant in California
A new variant SARS-CoV-2, named CAL.20C, has been identified in California. The New York Times has a story on this, though I’ll caution that you really have to read the whole article: https://www.nytimes.com/2021/01/19/health/coronavirus-variant-california.html
This new variant does not have any clear differences in terms of practical effects from other circulating variants of the virus. There may be a transmission difference, but it is very unclear. I am impressed that, if you read the entire article, a balanced perspective is provided. This should be contrasted with initial articles on the B.1.1.7 variant, which vastly overemphasized its apparent transmission gains and were extremely sensationalized.
As time has gone on, the apparent transmission gains of B.1.1.7 have been pared back. Even this article contains what at this point appears to be an overestimate, or at least an estimate on the high end, of the transmission gain in B.1.1.7, stating a 50% increase when recent evidence indicates a 30-50% gain. That’s a side point, though.
What’s important is that we have evidence of a new variant originating in California, and this is a variant that will be interesting to watch. I will continue to monitor news about it and report back here.
Israeli experience indicates that one dose of the Pfizer vaccine is not enough
Results from Israel indicate that a single dose of the Pfizer vaccine is not enough to provide reliable protection from COVID-19: https://www.theguardian.com/world/2021/jan/19/single-covid-vaccine-dose-in-israel-less-effective-than-we-hoped
This is a very preliminary report, based on a statement by Israel’s coronavirus response chief, Nachman Ash and some additional study results.
Dr. Ash made a statement that a single dose of the vaccine appears to be less effective than Pfizer reported in their data. That is particularly concerning since Pfizer reported efficacy of only 52% for a single dose.
In parallel, a study from Israel indicated that the second dose increases antibody levels by 6 to 12 times. That’s a big difference.
The reason Israel is particularly interesting here is that it’s probably the world leader in vaccine uptake right now. More than a quarter of the population of Israel has been vaccinated, and climbing. Combine this with universal national service in Israel, which creates a unified set of medical records for the country’s citizens, and it becomes a good place to study the effects of this vaccine on large populations.
This finding suggests that the FDA was right to insist on a two-dose regimen without delays or modification for the vaccines we currently have on the market in the US. It also suggests that the UK approach of delaying the second dose to maximize first-dose availability may be a serious mistake.
In the past, I’ve said that this may be a serious mistake. This report is the first evidence that I may be right. I would have preferred to be wrong, for the record.
COVID-19 variants carry antibody escape mutations
Virologist Paul Beniasz—who you may remember as the “anonymous pissed off virologist” whose musings I shared here from Twitter a few weeks ago—has released a preprint looking at several common mutations found in the B.1.1.7 variant and the South African variant, 501.V2.
In this paper, they assessed the ability of various individual antibodies to affect these virus variants. They found that the mutations they look at do weaken the ability of specific single antibodies to neutralize the virus.
Now, this sounds bad. However, I want to point out—as the authors do—that the natural immune response doesn’t rely on just one type of antibody. Instead, the immune system generates many different antibodies to try to control virus infections, targeting different parts of the virus. A single type of antibody targeting a single epitope is called “monoclonal.” A variety of antibodies, targeting different epitopes in a protein, existing in a mixture, are called “polyclonal.” What the Beniasz study looks at is the effect of these mutations on monoclonal antibodies.
The polyclonal antibody response helps minimize the impact of this in a normal human immune response. For the virus, these mutations may still offer small benefits that aid in virus survival, but overall, the immune response still eventually defeats the virus in the large majority of patients. However, the ability to escape some of these potent monoclonal antibodies may allow the virus to survive to transmit more frequently than it would have without these mutations—a selective advantage that might explain why these variants emerged.
This may also explain the apparent “transmission benefit” of these variants. Instead of actually being more transmissible, they may be better at surviving the immune response, thus making them more likely to survive until they can be transmitted. That would be an interesting mechanism for this apparent effect, but, it is just my hypothesis based on this new information.
In a practical sense, this finding has immediate applications in only one area: the choice of antibody-based treatments for COVID-19. If these variants are capable of escaping certain monoclonal antibodies, then it doesn’t seem appropriate to use those particular monoclonal antibodies as treatments in patients infected with these variants. That’s important information for the treatment of COVID-19, and may motivate physicians to favor the use of polyclonal antibody treatments over monoclonal antibody treatments.
You can read the preprint here, but be cautious—it hasn’t been through peer review: https://www.biorxiv.org/content/10.1101/2021.01.15.426911v1
What am I doing to cope with the pandemic? This:
Thinking about when we’ll get to take off these masks
Yes, this is a COVID-19 topic, which is unusual for this section, but I think it’s hopeful and something to look forward to.
It may not be apparent to everyone from my general advice to wear masks, but I really hate wearing them. They feel inherently furtive and I don’t think they facilitate normal human interaction. They’re uncomfortable and they are an additional thing to wash on a regular basis. They complicate loud speaking and singing, and they get in the way of endurance exercise.
They also happen to save lives and they serve as an essential prevention measure. Every complaint I might have about them is meaningless and trivial in comparison to that.
However, something that has been on my mind lately is this question: when can we take these masks off?
I think on some level, the mask is here to stay. I’d like to see people start wearing masks in public if they feel sick, in general. It’s a nice thing to do.
However, universal mask wearing will, eventually, end. We will no longer be continually worried about the spread of a virus that can create large numbers of asymptomatic and presymptomatic carriers. Universal mask wearing—well, what should be universal mask wearing—is meant to combat that situation. It will come to an end.
But, when? When will it be appropriate to not wear a mask when meeting friends in public?
I think in healthcare settings, masks are going to stick around for a long time. That’s to be expected.
However, as the vaccine rolls out to more people, there will come a point where you don’t have to wear a mask all the time. Personally, I don’t think that time has come in the vast majority of countries, but I do think it’s around the corner.
I also think that just being vaccinated isn’t enough for us to take our masks off—at least, not on an individual basis. Even if you’re vaccinated, we only have very preliminary evidence (at best) that this may prevent you from spreading COVID-19 to others. If you’re going to be around people who are unvaccinated, even if you’re vaccinated, then you should probably keep that mask on.
This will change, however. Here are the two things that I think will bring a change:
If we have clear evidence that the vaccine reduces transmission risk from vaccinated people to others in a way that is more effective than a mask
If the vaccine becomes available to anyone who wants it
In the event of (2) happening, I think it will become ethically reasonable for a vaccinated person to stop wearing a mask in public, about two months or so after the vaccine becomes so widely available. The risk of transmission will be the same then as it is now—though we don’t know that exact risk right now—but at that time, everyone will have had the opportunity to have both doses of the vaccine. At that point, for most people in most situations, being vaccinated will be a matter of personal choice about whether one wishes to be protected from this deadly illness or not. At that time, I think it will be reasonable to go to your friend’s party and not wear a mask. If you have a typical friend throwing a typical party.
Of course, there will be exceptions to this. Certain people who are immunocompromised or otherwise unable to receive the vaccine will still be at risk. However, people in those situations are already at a great deal of risk from many infectious diseases, and there is already advice about how to interact with people at such high levels of risk from infectious disease. Masks are often a part of that advice, and I expect they will continue to be. Perhaps the risk to such individuals will motivate more of us to wear masks in general when we go out in public, even after the pandemic. I suppose we will see.
We’re talking here about a future that is a lot closer now than it was before. In the US, there is a plan to deliver 100 million doses of vaccine in the next 100 days. If we keep ramping up like that, by the summer, we may all have had the opportunity to be vaccinated, and the worst of this may well be behind us.
I find that thought comforting.
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No corrections since last issue.
See you all next time.
Always,
JS