COVID-19 Resources
Updated on an ongoing basis. Last updated October 3, 2025.
Timely Topics
DNA Contamination
Q: Are Moderna’s mRNA COVID-19 vaccines contaminated with DNA?
A: No, Moderna’s mRNA COVID-19 vaccines are not contaminated with DNA.¹ Moderna’s mRNA COVID-19 vaccines simply use DNA as a template to produce large batches of product-specific mRNA. Moderna’s manufacturing processes consistently meet the guidelines set by organizations like the World Health Organization (WHO)² and the U.S. Food and Drug Administration (FDA)³ to control the level of DNA in its products. In adherence to these guidelines, after mRNA synthesis, the DNA template is degraded into small fragments, which are then removed from the mRNA during the purification process.⁴
To measure the amount of DNA remaining in the product after mRNA synthesis, Moderna uses a validated, industry standard, quantitative polymerase chain reaction (qPCR) method.⁵ Validation ensures that the techniques used to measure DNA are accurate, precise, and measure only DNA, and not other components, such as mRNA.⁶
Q: There have been publications that claim mRNA COVID-19 vaccines exceed limits for DNA. Does Moderna refute these claims?
A: A single group of authors shared results from studies using non-validated methodologies that inaccurately measured DNA in mRNA COVID-19 vaccines.⁷ The non-validated methodologies used in the referenced study lacked specificity to accurately quantify trace amounts of DNA due to the high concentration of mRNA and lipids present in the vaccine, resulting in a dramatic overestimation of residual DNA levels.⁸ When using a method capable of accurately differentiating between DNA and mRNA, the levels of DNA present in vials of Moderna’s COVID-19 vaccine were confirmed to be lower than the thresholds established in FDA and WHO guidelines.⁹
These claims have been refuted by researchers and regulators globally.
“A large share of the data and studies on suspected contamination of COVID19 mRNA vaccines circulating in the public are based on methodological deficiencies.” - Paul-Ehrlich-Institut, German Vaccines and Biomedicines Regulator¹⁰
“The Therapeutic Goods Administration (TGA) is aware of misinformation in recent media and online reports that claim the COVID-19 mRNA vaccines are contaminated with excessive levels of DNA. This is not the case. These reports are based on studies conducted by a small number of laboratories that have attempted to investigate the amount of DNA in COVID-19 vaccines… these recent studies fail to apply the required scientific rigor expected in pharmaceutical testing. As such, the results are not robust or reliable, and are creating confusion and concern regarding the safety of vaccines.” – Australia Therapeutic Goods Administration¹¹
“With over a billion doses of the mRNA vaccines administered, no safety concerns related to residual DNA have been identified. The agency has taken into account the totality of the mRNA COVID-19 vaccine product, including the lipid nanoparticles, as it reviewed the manufacturers’ specifications for residual DNA fragments present. Any contamination with residual DNA fragments is monitored routinely as a product specification.” – U.S. FDA¹²
Biodistribution Studies
Q: How long does mRNA stay in the body after injection? Does it accumulate with repeated administration?
A: mRNA is transient and does not accumulate. mRNA is quickly broken down and cleared by the cell's natural processes after it has delivered its instructions for producing a protein.¹³
Claims that the spike protein persists for months following vaccination are not aligned with the broader body of scientific evidence, and in some cases draw conclusions that are not supported by cited studies. A referenced study, Bhattacharjee S., et al [2025], relied on small, uncontrolled samples, and most importantly, could not distinguish whether spike protein was derived from the vaccine or from prior or ongoing COVID-19 infection.¹⁴ Of note, the authors themselves acknowledged the limitations of their findings stating: “this study is early-stage and requires replication and validation. We emphasize the critical task of discerning between meaningful results and random fluctuations in the data.”¹⁵
Q: Did Moderna study biodistribution with their COVID-19 vaccine?
A: Yes. In a well-controlled animal study conducted by Moderna and reviewed by the FDA and other regulatory agencies, spike protein levels, mRNA, and LNP components were found to be transient and there is no evidence of persistence beyond one-two weeks following each dose. Additionally, there is no accumulation of any of these with repeated administration. Following vaccination, spike protein, mRNA, and LNP components were mostly detected at the injection site and in nearby lymph nodes and the spleen, with lower amounts briefly detected in blood and other tissues.¹⁶ The distribution of mRNA-LNP vaccines is therefore consistent with how other types of intramuscularly administered vaccines distribute in the body through the lymphatic system.¹⁷
Moderna plans to present these data at an upcoming scientific conference and submit for peer-reviewed publication.