Fact check: A 2012 study did not use mRNA vaccines or result in animals dying from disease

A video which uses a research paper to argue that mRNA vaccines will make people fatally weakened to other diseases makes untrue claims about the study, according to the paper’s lead author.

Reuters Fact Check. REUTERS

The video, which has been viewed over 140,000 times on Facebook, carries the headline: “Why people may start dying a few months after the Gates vaccination”.

It opens with a screenshot of the abstract of a 2012 paper entitled ‘Immunization with SARS Coronavirus Vaccines Leads to Pulmonary Immunopathology on Challenge with the SARS Virus’. That paper is visible online here and here. The study researched vaccinated mice that were later exposed to a live SARS virus.

The speaker in the video says: “What happened in this study is that the animal models, after being challenged, got very sick and that some of them died. So that the last line of the abstract says: ‘Caution in proceeding to application of a SARS-CoV vaccine in humans is indicated.’” (Timestamp 1.06)

The recommendation for caution is indeed the final line of the study’s conclusion, as published on the above link, but the lead author of the study, Prof Chien-Te (Kent) Tseng (here), told Reuters by email that the animals in the study did not die.

He said that immunised mice “generated strong and highly protective antibody responses which fully protect immunized mice against lethal infection”.

He said that when the animals were exposed to the live virus, they developed eosinophilia (a high count of a type of white blood cells) but, despite this, they “found that mice survived the lethal challenge without showing any readily noticeable weight loss and other signs of illness.”

The speaker in the video goes on to suggest throughout the video that the findings of the study are applicable to RNA vaccines (here Timestamps 0.18, 1.49, 2.43).

However, Tseng, said the vaccines they had studied in the 2012 paper and the mRNA technology used in the COVID-19 vaccines are “very different vaccine platforms.”

Tseng also said that, while people should always be cautious about the safety of new vaccines, they should not be alarmed by his paper.

He wrote: “I feel our earlier report has raised that safety issue which has been taken seriously within the vaccine developers worldwide by different Institutions, including the World Health Organisation and the National Institute of Allergy and Infectious Diseases.”


False. Animals vaccinated in the 2012 study referred to in this video did not die when exposed to a live virus and the research did not involve mRNA vaccines, according to the lead author of the study referenced.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .