In 1961, a team of researchers in Paris discovered messenger RNA (mRNA). It would be almost 60 years before the molecule would be used in lifesaving vaccines against COVID-19 and other diseases. The road to mRNA vaccines has been decades in the making, battling no small amount of challenges, skepticism, and, more recently, misinformation. 

A brief history of mRNA vaccines

mRNA contains the instructions to produce every protein in every living organism on Earth. Since discovering mRNA, scientists have spent decades researching and rapidly improving technology to manipulate the genetic material into an effective vaccine. 

But the molecule is inherently unstable. Unlike DNA’s sturdy double-helix structure, RNA is a single strand that quickly falls apart outside of carefully controlled environments. 

Before mRNA could be used in vaccines, scientists had to find a way to keep it stable and intact as it was delivered to cells. In the late 1970s, researchers did exactly that by wrapping mRNA in a protective shell of fat molecules. 

The next decade saw incredible advancements in mRNA research as scientists produced mRNA in the lab and, finally, in the 1990s, tested the first mRNA vaccines in animals. 

In 2005, groundbreaking research produced synthetic mRNA, solidifying the reality of mRNA vaccines. This innovation enabled the production of custom mRNA sequences that could be quickly and easily altered to a precise target—such as the spike protein of a rapidly mutating virus. 

For 15 years leading up to the COVID-19 pandemic, researchers around the globe raced to produce the first successful mRNA vaccine. Clinical trials between 2009 and 2019 tested vaccines against rabies, HIV, the flu, and a dozen different cancers. 

The COVID-19 pandemic emerged just as science was finally ready to produce the vaccines to fight it. Far from a new, untested technology, COVID-19 vaccines were the culmination of over half a century of global mRNA research.

Timeline of milestones in mRNA vaccine history

Myths about mRNA vaccines 

Now, as the technology has set the stage for an entirely new way to fight disease, lingering myths about COVID-19 vaccines threaten to tarnish the perception of other mRNA vaccines on the horizon. These are the facts about some of the most common myths about mRNA vaccines.

Fact: mRNA vaccines are safe 

People who receive mRNA vaccines may experience mild side effects like soreness at the injection site or a headache. These typically pass within a day or two. 

Like with other types of vaccines, serious side effects from mRNA vaccines are possible but extremely rare. We know from decades of vaccine research that side effects emerge within two months of vaccination, a milestone billions of people worldwide have safely passed. 

At this point, the safety of mRNA vaccines has been rigorously investigated in tens of millions of people for over three years, with no evidence of widespread health issues or deaths. People are far more likely to become seriously ill or die from a vaccine-preventable illness than any vaccine.

Fact: mRNA vaccines are not gene therapy and don’t alter DNA

New and unfamiliar technologies typically raise fear and uncertainty. Unfortunately, vaccine opponents manipulate these normal concerns to fuel misinformation about the safety of mRNA vaccines. One of the most persistent myths is that mRNA vaccines are not really vaccines but DNA-altering gene therapy. 

Vaccine mRNA remains in the body only long enough to train the immune system to respond to its target. Because RNA is fragile and unable to enter the nucleus of a cell where DNA is stored, mRNA from the vaccine is safely cleared from the body a few days after vaccination. It’s biologically impossible for the vaccines to interact in any way with DNA.  

Gene therapy, by definition, involves altering the expression of a gene or genes. These therapies treat diseases by replacing or turning off a gene that isn’t behaving normally. mRNA vaccines aren’t gene therapy because they do not interact with or alter the recipient’s genetic material.

Fact: mRNA vaccination isn’t linked to cancer or other serious illnesses

There is no evidence of a link between cancer and any vaccine, including mRNA vaccines. Global cancer rates have been increasing since the 1970s. Yet, anti-vaccine advocates have attempted to blame a continuation of this decades-long trend on mRNA vaccines administered over the last three years.

False claims and myths attempting to link mRNA vaccines to cancer and other serious illnesses are based on anecdotes and unverified data from vaccine safety monitoring systems like Vaccine Adverse Event Reporting System (VAERS). These systems accept reports from anyone and cannot be used to confirm that an illness that happens to be diagnosed after vaccination was actually caused by vaccination.

Over 80 percent of the U.S. population has received at least one COVID-19 vaccine dose, and most received mRNA vaccines. Cancer affects around 5 percent of the U.S. population. There is bound to be some overlap between these two populations. 

Large-scale studies have repeatedly shown no increase in serious illnesses after mRNA vaccination. In fact, the vaccinated population has a lower rate of deaths for any cause than the unvaccinated population.

Fact: mRNA vaccines thoroughly researched and tested 

One of the most common misconceptions about mRNA vaccines is that the technology used to develop them is new and untested. This could not be further from the truth. 

Three factors allowed the COVID-19 mRNA vaccines to be developed in under a year: in-depth knowledge of other coronaviruses’ characteristics, decades of mRNA research, and an accelerated development process that could revolutionize how vaccines and other drugs are developed.

The virus that causes COVID-19, SARS-CoV-2, is part of a family of viruses called coronaviruses that fueled two epidemics in the last two decades alone. Because of this, scientists had a 50-year head start in understanding the genetic sequence and structure of the virus. With that knowledge, they used cutting-edge mRNA technology to quickly design and test potential vaccines.

Backed by historic international collaboration and funding, researchers made a risky bet: They launched overlapping clinical trials that would test the vaccine in multiple phases simultaneously. If their strategy worked, the vaccine would be available to the public in a fraction of the typical time. 

Fortunately, the bet paid off even better than the researchers could have hoped. These scientists hadn’t just developed a COVID-19 vaccine: They proved that with enough resources and less red tape, science can overcome some of humanity’s greatest public health challenges.

The future of mRNA vaccines

One reason mRNA COVID-19 vaccines were the target of concern and misinformation is the unprecedented speed at which they were developed. Just over a year elapsed between the first COVID-19 case in Wuhan, China, and the administration of the first COVID-19 vaccine.

Pfizer’s clinical trial launched in July 2020, a mere six months after SARS-CoV-2 was sequenced. Historically, vaccine development can take up to 10 or 15 years. In the case of diseases like AIDS, even decades of research have not yielded a viable vaccine. 

mRNA vaccines are changing that. Fast, inexpensive, and easy to develop, mRNA technology allows researchers to produce effective vaccines in a fraction of the time and cost, with only the genetic sequence of the vaccine’s target.

In the two and a half years since mRNA COVID-19 vaccine authorization, clinical trials began or advanced for vaccines against common viruses like influenza and respiratory syncytial virus (RSV), one of several viruses that cause colds. Influenza and RSV infect billions of people each year, killing hundreds of thousands worldwide. A universal mRNA-based flu vaccine could protect against many different flu strains at once, making it much more effective than the current flu vaccine. 

mRNA vaccines are in the pipeline for diseases that have eluded researchers for decades. For example, several clinical trials for mRNA HIV vaccines launched this year. Pre-clinical and clinical trials are also in progress for mRNA vaccines against two of the deadliest infectious diseases in history, tuberculosis and malaria, which claim millions of lives annually.

mRNA vaccines against aggressive, treatment-resistant, and late-stage cancers are also in the works. A personalized mRNA vaccine against one of the deadliest forms of pancreatic cancer successfully trained patients’ immune systems to fight off the disease and prevent relapse. The vaccine holds incredible promise against a cancer that rarely responds to treatment and kills nearly 90 percent of the people it affects. 

Another personalized mRNA vaccine halved the risk of relapse in patients with melanoma, one of the most common cancers. Other trials are testing mRNA vaccines against ovarian, prostate, lung, and colorectal cancers.