Possible low efficacy of current vaccines against Delta, possible Delta enhancement in the future.

This post is detailed, but adds an important new set of facts regarding the Delta Variant, the current vaccines, and prospects for a new booster shot.

You may have heard commentators in the last few days talking about the reduced efficacy of the current set of vaccines. There has also been a lot of discussion about a study from Israel about relatively high numbers of Delta COVID cases among vaccinated individuals.

First a little background on antibodies. Your immune system is making a random set of new antibodies all the time. In an ingenious mechanism, your immune cells “mix and match” pieces of a gene in your immune cells, producing the ability to make a zillion (scientific language for a whole lot) of different antibodies. Your body is basically making different “keys” that can fit into the “lock” of some new protein.

When you get an infection, several different antibodies may bind to the invading agent, on different regions, so you may be protected by several different “keys”. When this happens, a bunch of different things happen, including the manufacture of Memory B cells which makes just the antibody that binds to a particular protein. These cells get activated if you get re-invaded by something with that protein. All this to say, if you’ve had COVID, or been vaccinated, your body will have B cells with antibodies on them that bind to different parts of the Spike protein.

Before I say anything else, I want to repeat that I have not been vaccinated, but have recommended that high risk individuals get vaccinated! I’ve also pointed out many times in the past few weeks that countries with large vaccination programs have lower death rates due to Delta than other countries!

Literally 30 minutes after Thursday’s post on vaccine myths, a doctor friend of mine sent me a pre-print paper from a lab in Japan. Please note, this is a pre-print paper and has not yet finished peer review! The paper describes experiments using antibodies derived from patients infected with the Wuhan strain, as well as with the Delta Variant. They then studied binding of these antibodies to artificial viruses. The paper argues that Delta variant viruses are less neutralized by vaccines against “wild-type” or Wuhan strain vaccines. While the “wild-type” antibodies against Wuhan can neutralize a region of the Delta Spike protein called the Receptor Binding Domain (RBD) (Figure 1C), other antibodies binding to another region of Delta Spike protein actually enhance infectivity. Figure 1D from the paper shows negative levels of “neutralization” for antibodies that bind the N-terminal domain of the Spike protein. The paper calls this “enhanced”. Yes, this is the ADE I’ve been talking about.

Figure 1 from Liu et al 2021.

They suggest that with rapid changes in COVID variants, a new version of Delta is going to be able to use the ADE pathway in the near future, when Wuhan era antibodies will no longer be able to neutralize a mutated Delta strain.

To sum that all up in simpler language, it basically says that Delta is more infectious because it is partially using the ADE method of infection. Future versions may be less prone to be neutralized by Wuhan antibodies, making them fully enhanced. If this happens, we may have more severe disease in those who get infected with this new enhanced Delta.

They conclude by saying a booster against the Wuhan strain will not be effective in improving protection from Delta, and that a new vaccine against Delta will be required.

The material in the paper may help to explain why we have been seeing lowering levels of vaccine effectiveness in some countries.

Just to be very clear, they are not saying that this new enhanced Delta exists now, just that it may exist in the future.

I will pay close attention to this issue. If you have already been vaccinated or had COVID, a new Delta vaccine will be your best defense against possible ADE arising from a possible enhanced Delta.

If an enhanced Delta arises, and you have had Wuhan COVID or a Wuhan vaccine, and you haven’t had Delta, then you may be at greater risk for severe disease.

If you have had COVID since July 2021, you are likely already immune to the Delta variant, and this will not be an issue for you.

I am fully aware this complicated. Also, the CDC has rarely if ever discussed this possibility, so unfortunately, most of the people you talk to about this will not believe it. I am sharing this with you so you can make wise decisions for you and your family.

Some companies are already working on Delta versions of the vaccine. If you have had the current vaccines, or had COVID, you should get the Delta vaccines as soon as they are available.

Of course, discuss your medical history with your doctor before making medical decisions.

Another note on misinformation: My post from last Thursday generated a lot of discussion regarding censorship and misinformation. I argued strongly that the dangers of misinformation do not outweigh the benefits of free speech. Many of you are pro-vaccine and others are suspicious of the vaccine. I would simply urge this:

1) If you use the words “misinformation” and “disinformation” in a post or in a discussion, please come ready with evidence to support whatever claim your making! Don’t just throw out this word, support it!

I recently saw a video with a pro-vaccine medical person saying “we just need to keep pounding this information into people”. That is the wrong approach. With someone who is not yet convinced to get a vaccine, “pounding” away on them is just going to raise their defenses and exasperate you. Instead, gently show them your reasons for believing what you do! Explain to them what the data means. You may not convince them, but you may move them toward being more open to your view.

2) If someone makes a claim that sounds unfounded or that you don’t trust, don’t just tell them they’re wrong or make a counter claim, ask them to provide evidence, or where they got their information. You don’t have to do their homework for them! If they can’t produce any evidence, you are under no obligation to counter it. I’ve saved myself A LOT of work with this approach. It’s OK that they just heard it somewhere IF their source is reliable and has evidence themselves. You can still ask them to provide you with a link or something to that person’s statement. However, “I just heard it somewhere” is not evidence.

Part of the reason I’m not so worried about “misinformation” for myself is because of my regular use of suggestion #2.

Don’t fear, but be smart!
Erik

3 thoughts on “Possible low efficacy of current vaccines against Delta, possible Delta enhancement in the future.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s