The Novelty of mRNA Vaccines and Potential Harms: A Scoping Review

Comment: We have corrected duplicate text in locations as well as added references for immune-mediated phenomena.

Comment: Medical and science professionals need to be aware that this preprint is not truly a balanced review of the safety of the Covid-19 mRNA vaccines (or mRNA vaccines in general). What the authors have done is scour the literature for any citation that they can use to cast doubts on mRNA vaccines as a safe and effective platform. It’s cherry-picking combined with speculation. The authors tend to go far beyond what is said in the original publications, to try to make the case that the various components of mRNA vaccines are dangerous. They also ignore the evolution of the technology. Early mRNA vaccine designs tested in animals are not necessarily the same as the more evolved compositions that are now used in humans. The authors try to make the case that the SARS-CoV-2 spike protein is inherently dangerous - a toxin. Here, again, they scour the literature for anything they can use to cast doubts, when there is in fact no proof that spike proteins, in isolation, are inherently dangerous to humans. As a case in point, tens of thousands of humans (including one of the comment writers) have been vaccinated with the Novavax adjuvanted spike protein that is injected directly into muscles (i.e., without expression from an mRNA vector). Other spike protein vaccines have also been tested extensively and successfully in humans. The amount of injected spike protein, delivered as a bolus, greatly exceeds what is expressed over time on the surface of mRNA-transfected cells. And yet no significant safety signals have emerged from the use of these spike protein vaccines.

A balanced review of mRNA vaccines would include all of the dozens of publications on the overall safety of the Covid-19 vaccines both before and above their authorization/approval in multiple countries. This publications invariably show that these Covid-19 mRNA vaccines have an excellent safety profile. Yes, there are legitimate associations between these mRNA vaccines and myocarditis, particularly in young men. These safety signals exist, and are universally acknowledged by medical science. But the side effects are very rare, and are mostly rapidly resolved. In addition, Covid-19 is associated with a much higher prevalence of myocarditis (as well as other health dangers), so the net effect of the mRNA vaccines is to reduce the incidence of such complications. An additional point a balanced review would include is efficacy - the many millions of lives and trillions of dollars the mRNA vaccines have solved worldwide. Accordingly, we encourage readers to take these points into account when reading this article.

We also suggest that readers should do their own due diligence on the qualifications of the authors in relevant areas of medical science, and their membership of groups such as, but not limited to, the World Council for Health. That organization promotes the use of Ivermectin and other questionable and unproven interventions against Covid-19. Some of its members associate with conspiracy theorists such as those who believe Covid-19 is spread by 5G networks and promote an anti-vaccination agenda.

This comment is co-authored by Gregg Gonsalves of Yale University.

Neither co-author has a conflict of interest to declare. We receive no funding or other income from any vaccine company.