With all the rumors floating around about whether mRNA vaccines can alter human DNA, I wanted to address one question several of you have asked in different ways. It’s a very detailed and nerdy question and answer, but in case you love nerding out like I do (and need some good scientific reassurance), I wanted to share the question and it’s answer from a true expert. I’ve been posting some of the updates from my friend Rick Loftus, MD, the virologist, epidemiologist, immunologist and front line Covid ICU doctor.
One of our readers asked, “Can you ask Rick about the role of reverse transcriptase with both of the Covid vaccines? Some experts are saying that there is no risk because we don’t have it in our bodies unless we have retroviruses. But they fail to mention telomeres. Other opposing experts raise the point of retrotransposons too. I am not an expert in cellular science or genetics, but I do know enough that, in theory, it could be a problem. However, I can’t find solid answers to these questions, just conflicting info whether it presents a risk or not. There are a lot of unanswered and ignored questions from virologists making these vaccines.”
Rick was generous enough to take a break from the front lines to answer:
“This is a reasonable question to ask. And this issue has not been ignored by vaccinologists developing these RNA vaccines. I constantly need to remind people that RNA vaccines have been studied in live human beings for years. There’s about a half a dozen of them designed for other viruses (like CMV) that have been in human subjects who are beyond five years of their doses. So the perception that we have no long-term safety data on RNA vaccines is not really true. We have multiple year data on RNA vaccines against other viruses, just not for Covid, since Covid was only discovered and sequenced exactly a year ago.
In spite of all the rumors about how these vaccines could change your DNA, there has been no evidence of RNA sequences from the vaccine somehow being reversed transcripted into DNA. There was one case report where the Covid virus itself (not the vaccine) was suspected of accomplishing this, but it was more of a hypothetical assertion by one of the scientists reporting the case, and they did not actually prove this hypothesis.
Remember that viruses that engage in reverse transcription do so with custom made individualized enzymes designed for that sequence that are designed so to speak for the cells that they invade. I use the term “designed” lightly because of course viruses evolve to adapt to their environment and to their host.
While there have been conspiracy theories asserting that the Covid virus was designed in a lab, we have observations of the structure of this virus that strongly support that it evolved in animals, likely bats, just like SARS-CoV 1. Let’s remember that this Covid virus has been evolving to be best suited to bats. Part of why it makes illness in humans is that it’s not suited for us, because most viruses do not want to kill their host. It compromises their ability to spread, which is what viruses are trying to do. Again, I’m making them sound like they are human beings with motives, but of course viruses are just a force of nature.
So while there are enzymes that belong to endogenous retroviruses in human DNA, it is a real stretch to assert that one of them would be fully active in a cell in a human and be capable of reverse transcribing the vaccine sequence into the human DNA. I feel like it would be similar to worrying that your five-year-old will somehow leave the house, get in your car, start it, and drive down the street. Perhaps not utterly impossible, but there are so many factors that count against it. And this gets into what I have said before about risk perception.
In the United States, this virus has already infected 20 million human beings at least, probably a lot more, and has killed hundreds of thousands of people. The risk from the virus is gob-smacking and horrifying and is 100% likely to happen, since we’ve all watched it happen. In the meantime, worrying about hypothetical scenarios about how a vaccine might be harmful (anticipating outcomes that may have zero probability or close to zero probability of ever happening) gives the perception of such potential or imaginary risks more weight than I think they deserve.
Every day that I get up and drive to work, I could be struck by lightning, which is never impossible, but just overwhelmingly unlikely. And so I drive to work. And I have yet to be struck by lightning. Again, it is not impossible for me to be struck by lightning while driving to work, but it is an astronomically small likelihood. And so I drive. The risk from the vaccines is overall much smaller by hundreds of orders of magnitude compared to the observed known confirmed obvious harm to individuals and society by the actual virus. Vaccines are the only way that we are going to get back to anything resembling our lives before Covid.
Also, I would add, because we have allowed this virus to replicate widely in tens of millions of people- mostly in countries that are run by anti-science populists- we have allowed the evolution of the hyper-contagious strains like B.1.1.7 from the United Kingdom and B.1.351 from South Africa. Why is this important? Because it moves the goalpost about what we are trying to do with vaccines. Originally people like me thought we needed immunity in 60 to 70% of our population to stop the spread of the virus. That was a target we could have hit probably by September 2021, assuming reasonable competence in distributing the vaccine – something that would have been impossible under the incompetence of the Trump administration but will be possible with competent people back in power under Biden.
If the contagiousness of a virus increases, the number of people in the population that must be immune to prevent it from spreading is higher. This is why Tony Fauci said a few weeks ago that we may need to achieve immunity in 90% of our population, instead of 60 to 70%. It may take us a year to get to that point, and we are not helped by the fact that large numbers of our population absolutely refuse to get the vaccine or even spread false conspiracy theories that the vaccine will harm them in ways that it won’t. Trying to get 90% of the population immune is a very ambitious goal. Even with aggressive vaccine outreach, we may not reach 90% immunity of the population until December of this year, and that’s if everyone cooperates, which with Americans, is usually something you cannot count on.
Part of why this virus killed so many people in this country is because many Americans refused to do very reasonable, modest things to keep their neighbors safe. If we accomplish immunity by letting the virus run amok and infect tens of millions of people, we will definitely crash the health system and there will be many hundreds of thousands of preventable deaths, not to mention millions of people permanently disabled by Long Covid, which seems to be an aspect of this virus that I never hear politicians or members of the public talk about, but which is something that most of us in medicine are much more worried about than the death rates per se.
That, of course, and having all the Covid cases happen all at once, would be a recipe for crashing the health system and traumatizing health workers (and those they care for) forever. I do not think laypersons understand that by letting this virus run amok the way we have in America, they have guaranteed that we will have preventable deaths from diseases that are not Covid, because the hospitals are simply overwhelmed.
Although things seem to be trending slightly better right now, my local hospital was recently 2/3 Covid cases. What happens to the people who have heart attacks, strokes, or appendicitis? Their care will be compromised and some of them will die even though no one should die in 21st century America from these conditions. And I have to say, as you know, as a medical scientist, I get full of despair when I see how many of the citizens will not do the things we have been begging them to do to prevent such scenarios. All of this is happening because Americans seem to be very focused on their individual well-being and are not doing the things to keep society collectively safe. We healthcare workers are paying that price, and there’s going to be a mass exodus of doctors and nurses from the practice of healthcare once this immediate crisis is over. Many of them are barely hanging on right now as it is.
That is why I spend time trying to educate the public about how to keep themselves safe from getting and spreading this virus to others, and trying to encourage people to use the extraordinarily safe vaccines. Relative to other vaccines that we routinely use in adults and children in this country, the safety of Covid vaccines is very good, better than the shingles vaccine. Again, it is common for the Americans to drastically exaggerate the risks of vaccines while having zero life experience with what these viruses do in the wild when they are not controlled. Measles is a good example.
In Southeast Asia, measles causes brain damage and death in a lot of children. Americans have never seen that, because we live in a country where most people get vaccinated. They therefore judge the risk of something they can see and experience- measles vaccination- and have zero knowledge of the much more horrifying downsides of actually getting the measles virus. Nobody in two generations has seen mumps in the United States, But in southeast Asia where they don’t have childhood vaccinations, it can kill little kids. An entire village of children that have lymph nodes the size of softballs to the point where they can barely breathe or swallow their own saliva. Many of the boys will wind up permanently sterile from the effects of mumps.
Again, since the Americans are hot house orchids and have never lived in a country without vaccines, they drastically overemphasize the downsides and side effects of vaccines and have zero experience with the much more massive and horrifying downsides of natural viruses run amok.
All of that said, I think the question about whether vaccine RNA can somehow be reversed transcripted into human DNA is an understandable question to ask. But I hope I have explained why this concern probably does not represent a true risk of the vaccines, and it is not something that has been ignored by the vaccine developers. Science is always changing, and we learn as we go, but as of today, we have seen no evidence for this. And we have seen overwhelming evidence of how incredibly dangerous this new virus is in producing deaths and disability, not to mention massive societal disruption.
The way I see it, widespread use of the vaccines against Covid are the only way we will ever see our society return to life like it was before Covid. Otherwise, it will take a decade for the natural virus to kill as many people as possible, before things start to calm down biologically. That is a much more “Mad Max” scenario than I wish to think about.”
*A special thank you to Rick for taking the time to answer this one question that many of you have asked about. Please don’t expect him to answer other questions, however. And since I am not an expert in virology, immunology, or Covid, please don’t expect me to answer your questions about something we’re all learning about! For that matter, please don’t ask and expect reliable answers about Covid from anyone who is not an expert in virology, immunology, and Covid. If you’re getting your advice from internet doctors or high-end luxury cash-pay doctors who haven’t touched the front lines, a virology lab, or a public health department, please ignore any rumors you might hear!
