MARY REICHARD, HOST: And joining us now to talk more about the vaccines themselves is WORLD Medical Correspondent Dr. Charles Horton. Good morning!
CHARLES HORTON, GUEST: Good morning!
REICHARD: Dr. Horton as we know, these three COVID-19 vaccines all use new technology. Moderna and Pfizer’s use mRNA protein technology while Johnson and Johnson’s uses viral vector technology. Can you explain the difference?
HORTON: Sure! Fundamentally, all vaccines for COVID-19 have the same goal, which is to teach the immune system how to recognize the virus so it can attack it. And by “recognize the virus,” what we really mean is recognizing one or two distinctive things about it – just like you or I might describe someone at church: see the tall fellow with the blond hair and the striped shirt? To continue that analogy for a moment, I could say that to you, or I could show you a picture of him. Either way you’d come to understand who I meant.
In the case of coronavirus, a protein called spike protein is what we’re teaching the immune system to look for. The Johnson & Johnson vaccine uses an adenovirus vector. That’s a virus that normally causes the common cold, but they made some changes. Instead of being able to replicate and make you sick, they replace that with the ability to make cells display spike protein. Again, that’s the key that coronavirus uses to invade cells. The mRNA vaccines are more direct. They just directly give cells a recipe for that protein. But, either way, the immune system learns that spike protein means this isn’t welcome. Attack it.
REICHARD: Now, the pharmaceutical companies developed these vaccines really fast. And that makes a lot of people nervous. The latest Pew Research poll shows 30 percent of Americans don’t plan to get vaccinated. Are there legitimate reasons to be concerned about these vaccines’ potential effects on the body?
HORTON: The risk of side effects is never completely zero, with any medical procedure or intervention. The big question then becomes how bad those side effects are, and how likely they are.
We know from the phase three trials that were done prior to the emergency use authorizations that at least in the short term, the risk of serious side effects is very low.
The life-threatening allergic reaction called anaphylaxis that you might have heard about is rare. This is the same reaction that people with severe allergies to things like foods, bee stings, that sort of thing carry an Epi-Pen to treat.
We can’t completely rule out long-term effects from the vaccine, for the same reason we can’t rule out long-term effects from the virus: only decades of hindsight can do that. But we can say that some of the worries that people have discussed are things that aren’t going to happen.
REICHARD: And what are some of those worries?
HORTON: First off, you will not get coronavirus from any vaccine sold in America right now, because the vaccines sold here do not contain coronavirus. They show your immune system a picture of the virus and say, “if you ever see this, destroy it,”
Second, it won’t permanently change your genetic code. It won’t even temporarily change your genetic code. DNA gets transcribed to mRNA – that stands for messenger RNA, because it carries a message—and then transcribed to proteins. Once the mRNA has been transcribed enough times, it’s used up. The cell breaks it down.
Third, the vaccine won’t make you infertile. The vaccine causes you to make antibodies against spike protein, just like you would develop from getting COVID-19 and recovering from it. They don’t attack the placenta. It just lets you fast-forward through the part where you get sick with COVID-19 to develop those anti-spike protein antibodies.
REICHARD: The CDC just announced yesterday that fully vaccinated people can gather with other vaccinated people without masks. But what about being out in public after getting fully vaccinated? Do people still need to wear masks or worry about social distancing?
HORTON: Ah, $64,000 question! This was a common-sense decision on the CDC’s part and I was glad to see it. Remember, people who have coronavirus are contagious because the virus is able to hijack cells in their bodies, make copies of itself, and send them out into the world. That’s how all viruses work. So, if your immune system is already primed to fight it off, presumably the virus gets much less of a chance to do all of that. We know that vaccinated people can still get a mild case of disease, which means it might be possible to pass it on, but it should be much less likely.
That means there are two questions here. The first is can start to return to normal life after getting the vaccine, and the answer is yes because the chance of getting severely ill goes way down, and also because the chance of transmitting the virus goes way down. The second asks should we wait until more of the public has had the vaccine before we completely put away the masks and stand close together. From a standpoint of being considerate to other people, being our brother’s keeper, yes, I would give that a little more time.
REICHARD: And finally, Dr. Horton, it’s been one year since the pandemic spread across the country. Do we now understand more about the long term physical effects of the virus on the body?
HORTON: The most common features of “long COVID” relate to the brain and the heart – there’s a “brain fog” with fatigue, trouble focusing, and memory loss, and there’s a decrease in heart function. But it’s a lot easier to quantify heart function, so let’s focus on that for now.
The good news is most people who get COVID-19 don’t seem to develop any heart trouble, and the not-so-bad news is that for those who do, most recover. Pro sports leagues looked carefully for heart damage in almost 800 athletes who’d tested positive, found abnormal screening results in thirty of those, and actual inflammatory heart disease in five of them.
There is a flip side to this, which is we’re talking about pro athletes here. They’re in great shape to start out, and injuries that would keep me out of church-league softball for a season might keep these guys on the sidelines for a few weeks.
But all in all, thankfully, it sounds like long COVID is a much less common phenomenon—and not as significant a phenomenon—compared to what initially thought it might be.
REICHARD: Dr. Charles Horton is WORLD’s medical correspondent. He lives and works and raises his family in Pennsylvania. As always, thank you!
HORTON: My pleasure!