Addendum: I accidentally used the term “effectiveness” rather than “efficacy” when discussing the vaccines below – this has been edited. That is what happens when you type things up at 11 PM…yay for being imperfect.

With Thanksgiving a week behind us and Christmas around the corner, there has been a lot of discussion on travel and potential spread of COVID (SARS-CoV-2, or whatever terminology you prefer).  Many people are doing their part, remaining at home and minimizing potential spread of the virus to their loved ones and the community surrounding them.  Trust me when I say the medical community is grateful to those taking this approach.  

I think we all understand how frustrating this time is.  We don’t get to see family and friends the way we used to.  Many kids are stuck at home with virtual learning, while others may be in a hybrid form of it.  This leads to a decrease in socialization and learning skills in some kids, while we are seeing an increase in obesity and depression in other kids.  

So what is the big solution everyone is hoping for? A vaccine.  The news in the last few weeks has released some promising information on this.  Within 1-2 weeks we were told of new vaccines being produced that seem to have promising results.  There has been mention of both vaccines having an effectiveness of 90-95%.  It sounds like access to these may be sometime in mid-December depending on the roll out strategy.  There seems to be some light at the end of the tunnel, right?

We have received a LOT of questions about these vaccines in the office, and I think there are still some talking points that need further discussion.  Let me make one thing clear: I will get the vaccine once it is available for me and I have the safety data reported from their trials.  Nothing reported below is meant to deter you from getting the vaccine once it is available.  The information is meant to answer any lingering questions you may have based on the current data as of December 1^st, 2020.  With that said, let’s get to it.

Why do I keep hearing about a “new” type of vaccine?

The two most recently discussed vaccines from Moderna and Pfizer are referred to as messenger RNA (mRNA) vaccines. If you have not reviewed your high school biology notes recently, mRNA is a strand of genetic information used to created proteins and other products in the body. This vaccine style is new, however mRNA technology has been around for quite a while in research for other potential drugs including those that fight cancer. Previous vaccines may use pieces of viruses or bacteria that are then injected into your body, allowing your body to recognize these as foreign and mount an immune response against it.

Messenger RNA vaccines act differently.  The mRNA is taken up by your local cells after injection; these cells use the information in the mRNA to create a protein (in this case, the spike protein of the SARS-CoV-2 virus).  The mRNA is then destroyed by the cell, and the protein that was produced gets expressed on the outer part of the cell.  This outer protein on the cell gets recognized as foreign by the body, which allows for the immune system to mount an attack and create B-cells and T-cells for future defense against infection.

Can I get COVID from these vaccines?

There are NO viral particles present in these vaccines.  You can NOT get COVID from these vaccine types.  Let’s squash that discussion now.  You may get side effects from the vaccine that seem similar to illness, but you are not actually contracting the illness nor can you pass it on to others from getting the vaccine.  

What Side Effects Should I Expect?

Do you ever wonder WHY we get the symptoms we get when we are ill?  Many of those symptoms are our body’s defense mechanisms against a foreign object.  Fevers (which I have discussed in a previous post), swelling, soreness, body aches, headaches – all of this is secondary to the inflammation created from our body’s immune system while attempting to learn how to fight an infection.  So is it possible you will get these symptoms after getting a COVID vaccine?  Yes, it is.  However, it is important to remember that this is YOUR body responding to the vaccine.  It is not the vaccine creating the symptoms.  Again, you cannot get sick from the mRNA product in the vaccine, nor can you spread illness from the mRNA.

How Effective Are These Vaccines?

Recent news has reported that the vaccines vary in efficacy from 90-95%.  This indicates that the vaccine potentially prevented 95% of potential illness in the participants who got the vaccine.  Sounds great, right?  Honestly, it does.  Imagine if we can protect up to 95% of people from getting sick?  

One question we get asked often is how do they get these efficacy numbers?  To keep the explanation simple, let’s imagine two groups of people.  One group received the vaccine.  The other received a placebo shot.  Neither group knows what shot they received. Now we release them into the public and follow up in a set amount of time and see who got sick.  The efficacy gets calculated when comparing the number of sick patients in the vaccine group to the sick patients in the placebo group.  Ok, it may be more complicated than that; I don’t want to get into the more specific details on how a double-blind randomized trial is run. One benefit to these, however, is they can also follow up on side effects during this time period as well.  

With the Vaccines Apparently Working So Well, Herd Immunity Should Be Easy, Right?

One would expect that a vaccine allowing for 90-95% efficacy of prevention of an illness would get us to a “herd immunity” setting for the population rather quickly. This is not always the case.  The effectiveness data tells us that these vaccines prevent INDIVIDUAL illness, but do nothing to tell us if they prevent SPREADING the virus to others.  

Confused?  Let’s review the vaccine this way – when you get vaccinated and develop antibodies and other immune cells, these stay in the blood stream to prevent widespread illness and complications from the virus.  If you are exposed to the virus these cells prevent you from getting really, really sick.  However, the virus can hang out in your nasal passages and then get spread the next time you sneeze.  

The polio vaccine is an example of this.  Originally, the polio vaccine was taken as a liquid.  You would drink it, and then your gut would develop antibodies against the organism. Antibodies in the blood would also be created, preventing risk for negative outcomes if polio was somehow contracted in the future.  Since polio is transferred mainly through the fecal-oral route, these antibodies in the gut would help prevent you from spreading polio in the future.  

However, this vaccine had bad side effects, and an inactivated (dead) form of the vaccine, which was injected rather than drunk, was created (the oral polio vaccine utilized a live version of the virus in comparison).  This led to immunity within the blood stream to prevent significant illness in the host (mainly paralysis), however this did not lead to the creation of gut antibodies.  This meant that if the vaccinated person gets exposed to polio later on, they could still pass it on in their stool to other potential hosts while showing no symptoms. However, once that person is exposed to the live virus in the gut, that person’s immunity would finally be complete, allowing for gut antibodies to be formed without having any negative effects from the pathogen, protecting from infection AND spread if exposed a second time.

So why is this concept important when discussing the COVID vaccines?  When we say a vaccine created a 95% efficacy, that number only represents the individual in terms of illness.  It does NOT represent the inability to spread the virus.  It is possible that a person who is vaccinated will determine (on their own) they are safe to return to “normal daily activity,” when in fact they could still spread the virus to other unvaccinated individuals.  Now, if they get exposed to the virus, they could then develop an innate immunity from illness and the potential to spread it, but in the process they could also be a super spreader to others.  

Will We Need To Get the Vaccine Series Only Once or Every Year?

Great question.  We honestly don’t know.  We have not had the vaccine or the illness around long enough to know if it leads to lifelong immunity or waning immunity.  Other coronaviruses tend to have a waning immunity (hence why you can get things like the common cold every year).  Early studies on the duration of immunity toward SARS-CoV-2 are encouraging, yet still small in data.

I learned of a recent study currently in preprint (meaning it has NOT gone through peer review yet) done by Dan, Jennifer, et al through the “This Week in Virology” podcast. It reviewed immunity duration in 185 individuals whom had a COVID infection.  It seems to indicate that the spike protein memory B-cells are still in high volumes 6 months out from infection.  The various T-cells used in immunity declined over time, having a half-life of about 3-5 months – a half-life means that in that 3-5 month span half of the original T-cells that were created during infection are now gone.

What does this mean for the vaccine?  It is still hard to say.  I am hopeful that if this study is reviewed and accepted (I expect it will be), it will help indicate that B-cell production and activity will remain elevated long term.  The spike protein that these immune cells target during acute infection is the same spike protein utilized in the mRNA vaccines.  Even if T-cell persistence is minimal, one would hope that the memory B-cells and antibodies would be enough to stave off significant infection while the body ramps up T-cell production during acute infection in the future.  In other words, maybe the vaccine would be an “every 5 years” type of vaccine rather than every year.  However, we still don’t know.  

Will My Child Be Required to Get the Vaccine As Soon As It Is Released?

Many parents have this question.  When will my kid be able to get the vaccine?  Or they may ask, “Will my kid HAVE to get the vaccine as soon as it is available to the public?”  

As of now, it appears the strategy will be a step wise approach.  Early vaccine distribution will be targeting at risk populations and front line workers.  As they progress through these steps, more and more people will have access to the vaccine.  However, current studies on these vaccines did NOT include younger children.  When vaccine data is not available for a certain age group, usually that group is not included in the initial distribution of the vaccine.  I am sure there are studies going on now or in the near future targeting a younger age range; however, kids will probably be the last group to get the vaccine.  

Summary

In the end, I feel the vaccine (whichever one we end up using) will have a huge benefit for our population as a whole in battling the current pandemic.  There are still a lot of questions out there about it, and I am hopeful those answers will be readily available soon.  

Things to keep in mind:

We STILL need people to social distance, wear a mask, and be responsible (even when the first wave of vaccines are utilized).

Once you get the vaccine, it does not mean we can all return to “normal” right away (I said it again for emphasis).

We still do not know if the vaccine prevents spread of the virus, even if you show no symptoms. Thus, you can’t rely on others to get the vaccine to completely protect you. Eventually we hope herd immunity will prevent the spread of the virus enough to totally rid us of it, but just like other viruses we get vaccinated against (ie Chicken Pox and Measles), it may never fully go away.

Vaccines can have side effects, typically being soreness, fever, fatigue, headache, or achiness.  This is NOT you getting sick.  This is your immune system responding to the vaccine and doing its job.  

You can NOT spread COVID from an mRNA vaccine.

Stay Safe.  Stay Healthy.  Take Care of Each Other.

Imperfect Dad, MD