Vaccines

Thank you

First of all and important: Thank you guys for such nice reactions to the new book. It was a nice day, Monday. I am tremendously appreciative of your support and nice messages.

Tooth Fairy Follow-Up!

You may recall the Tooth Fairy discussion from a previous newsletter, in which I posted a survey fielded by Lydia Musher in her newsletter (find it here!). She’s written up the results, which I will mostly let her speak to in her post, although I will note the top line result that about 70% of families report they at least started with a Tooth Fairy with their kids.

There is some interesting discussion about the tension between “preserving magic” and “lying”, which resonated with me. Lydia has some thoughts on how these may not be in conflict. In our particular case, I think I would have erred towards more “preserving magic” but Jesse felt strongly that we not lie if asked. Which is how one day I was forced to directly answer the question, “Is the tooth fairy real?” with “No.” Which was followed up with: “I didn’t think so, since other fairies are not.” Touché. Anyway, check out the post!

Vaccines: Questions Answered

Finally, we get to main topic of today. The COVID-19 vaccine. My inbox is full of questions: would you get it? Should I get? When can we get it? I’m pregnatn, what about me? Our kids? Help!

I’ve collated some answers below, drawing on the expertise of some of the COVID-Explained team, including Lindsay Shultz, Susan Johnson and Ashley Battenberg.

To set the stage, in case you have not been following closely. There are two vaccines which have applied for Emergency Use Authorization (EUA) approval in the US, one by Pfizer and one by Moderna. Both have shown very high efficacy (well over 90%) in large Phase III trials, with limited adverse events. There are other vaccines on the horizon, including one from a team in Oxford and a Johnson and Johnson vaccine. I’m going to focus here on the Moderna and Pfizer option since they’ll come in first.

Both of these vaccines are “mRNA” vaccines. This a new type of vaccine, and I think there is some understandable wariness about it. Having said that, the very large Phase III trials have shown extremely good safety data. There is a lot of reason to be optimistic and to trust these vaccines. But it’s hard to trust something you don’t understand well. I think our big challenge in the next months it going to be in helping people better understand teh vaccine technology.

Here’s a start.

Can you explain what mRNA is? How do these vaccines work? Also, I heard it changes my DNA. That seems scary.

In your cells, you have double stranded DNA that serves as the instructions for everything your body does. When you want to use a specific set of instructions, your cells briefly unwind the DNA double strands to copy one strand into a single-stranded copy called messenger RNA, or mRNA. It’s called this because it serves as a “messenger” by bringing this copy of instructions to the parts of your cell that serve as protein factories (ribosomes), where the instructions are translated and made into proteins.

mRNA vaccines work by inserting an mRNA molecule into your body, which your cells then read as instructions to produce certain viral proteins (specifically, the SARS-COV-2 spike protein). Your immune cells then recognize this viral protein because it is foreign—your human DNA doesn’t contain any instructions on how to make this protein, so it has never been made before.

When your immune cells recognize the protein, they make antibodies against it. The antibodies are, effectively, antibodies against the SARS-COV-2 virus. If the actual virus is introduced to your body, the antibodies recognize the spike protein and destroy it.

mRNA does not change your DNA. It survives in cells for a very short period of time—usually a few hours.

Here’s an analogy, courtesy of Ashley Battenberg. Think of your DNA as a recipe book. The mRNA is a quickly disintegrating recipe card, lasting only a few hours. This recipe card isn’t able to suddenly jump into a recipe book that you have stored in a closed cupboard in your kitchen. It’s written on a different type of paper, it’s in a different part of your kitchen, and recipe cards just simply can’t jump into and merge with a recipe book. Even if you put it inside the recipe book, you would never confuse a page in your recipe book for the recipe card. They’re both instructions but are clearly recognizable as different things. Just as DNA and mRNA are different things. The mRNA does not change your DNA. It just can’t.

Can I get the virus from the vaccine?

No.

Many traditional vaccines use a killed or weakened form of a virus to prompt an antibody response. In these cases, people sometimes worry that they could get the virus from the vaccine. This is why we have so many safety protocols.

However: mRNA vaccines don’t work like this. They do not contain the virus. They do not encode the whole virus. The mRNA only contains the instructions to make one specific protein (the spike protein). SARS-CoV-2 is made up of many proteins that allow it to infect us, and it is simply not possible for the spike protein alone to infect and replicate in our cells (this is what happens when we are “infected” with a virus).

It is possible, even common, to have side effects after the vaccine. These are due to the reaction of your immune system, not an infection. There is no virus replicating in your cells (no infection), but your immune system is triggered to respond as if there is. For this reason, many of the symptoms that you experience after a vaccine might be similar to the symptoms that one would experience upon infection. These symptoms are a sign that your body is building up immunity.

What kind of side effects are we seeing?

Relative to other vaccines, we are seeing more significant side effects, although they are in the same space as typical vaccine side effects. To quote from Science Magazine:

The independent board that conducted the interim analysis of Moderna’s huge trial found that severe side effects included fatigue in 9.7% of participants, muscle pain in 8.9%, joint pain in 5.2%, and headache in 4.5%. For the Pfizer/BioNTech vaccine, the numbers were lower: Severe side effects included fatigue (3.8%) and headache (2%).

These effects seem to vary by age, with younger people having worse side effects. Anecdotal: we’ve heard some of these side effects described by a friend in their 30’s as “feeling like a wicked hangover”- not pleasant, but manageable. The age variation is good news: older individuals who get more value from the vaccine are also less likely to have serious side effects.

On the one hand, I think there will be a desire to minimize this to encourage vaccination. In my view, realism is important here. It seems like the side effects are worse than usual vaccines, but these are short term.

What about pregnant women and kids?

Both pregnant women and children were excluded from vaccine trials (kids here means less than 16). This means that they may need to wait for safety data. This could be developed in the next few months as we start vaccination in general.

The most salient immediate question is on pregnant health care workers. Health care workers are in the first vaccine group, possibly even by the end of this year. So there is a right-now question of whether pregnant people should be excluded from these vaccination. The answer seems to be “not necessarily.” The current ACIP recommendations suggest that pregnancy should be a “precaution” but not rule out getting the vaccine.

This is likely to come up also when we move to Phase 1B of vaccination, which includes many more groups that will have pregnant women. It’s an uncomfortable position: there is no particular reason to think the vaccine would be an issue for pregnant women, but we are always wanting to be more cautious. There will not be easy answers until we see safety data.

I know a lot of you have written to me asking for more answers. I wish there were more. My sense is that the somewhat ambiguous recommendation comes because there is, on the one hand, no reason to think that pregnant women would be at higher vaccine risk. And, on the other hand, we are always more cautious about pregnant women.

Kids will not get vaccinated until we have safety data on them. Although, honestly, the safety protocols are unlikely to be the limiting factor. Since kids are low risk, and will be protected by vaccination of their parents, they are likely to be among the last vaccine recipients regardless. By the time we get enough vaccine for them, I’m guessing we’ll be through safety trials.

A lot of people are saying it’s safer to wait, not to be in the first group getting the vaccine. Would you get the vaccine right now?

Yes. (This is from me, Emily, and also the actual experts). There is a lot of safety data. The trials were large. And, also, I don’t want to get COVID. I am not likely to be in the first (or second, or third) traunche of vaccine-getters but I will get it as soon as I am able.

How worried are you about vaccine resistance?

Medium. In the short term, the limiting factor in vaccination is going to be vaccine availability not demand. In the medium term, I do worry a bit about resistance. In the end, we may need more sticks than carrots to get over the last hump (i.e. school or work attendance is conditional on being vaccinated).

I am reassured, though, by the high efficacy. With a 95% effective vaccine, you do not need 100% vaccination to achieve herd immunity.