Researchers concerned about SARS-CoV-2 vaccine development

A growing number of researchers are voicing their concerns about the rapid pace of SARS-CoV-2 vaccine development.

Crucial safety steps are being skipped on a product that surely will be marketed to every person on the planet. The rush to market appears to be driven by potential profits not a desire to save lives. Several effective therapeutics exist and more are emerging that can prevent cases and effectively treat patients. See Our NEWS PAGE  for posts about these therapeutics. A rushed vaccine product that has not undergone extensive safety testing could do more harm than good. Helen Stillwell, a research associate in David Hafler’s immunobiology lab at Yale University,  wrote on the Virology blog article:

“Yet, it is still unclear whether Moderna’s vaccine candidate will provoke a sufficient immune response to be effective against SARS-CoV-2. The premise of gene-based platform technologies rests on the ability to target segments of the viral genome that are involved in provoking host immune response. Although we can make well-informed choices on what sequences provoke immunogenicity, we won’t know if the optimal sequence has been selected until human trials are completed (Loftus 2020). So too, there is no precedence for a vaccine of this kind since there are not yet any approved human vaccines that use this gene-based technology (Loftus 2020).

Virologist Dr. Jose Esparza commented the following on Moderna’s vaccine candidate: “The rapid manufacturing of the RNA vaccine is great. But preclinical experiments are important to assess safety before carefully moving ahead with small phase I trials in human volunteers. Special attention should be placed to a potential ‘Antibody Dependent Enhancement of Infectivity’ triggered by the induction of binding but no neutralizing antibodies.”

From a paper in Current Opinion in Virology:

“The concern that is extrapolated from the FIPV vaccine experience to human SARS-CoV vaccines is whether vaccine recipients will develop more severe disease if they are exposed to or infected with SARS-CoV after neutralizing antibody titers decline. The second concern is whether recipients of a SARSCoV vaccine would be at risk of developing pulmonary immunopathology following infection with an unrelated human coronavirus e.g. 229E, OC43, HKU1 or NL63 that usually causes mild, self limited disease. Although findings from preclinical evaluation have revealed these concerns, studies in animal models may not be able to provide data to confirm or allay these concerns.”

Animal models for SARS and MERS coronaviruses

More Articles on concerns by the scientific community:

Boodman, E. 2020. Researchers rush to test coronavirus vaccine in people without knowing how well it works in animals STAT

Laguipo, Angela Betsaida B. “Could Rushing a Coronavirus Vaccine Cause More Harm?” News, 12 Mar. 2020,

Lanese, N. 2020.Researchers fast-track coronavirus vaccine by skipping key animal testing first. LiveScience

Lyons-Weiler, et al. “How the COVID-19 Pandemic Will End.”, 16 Mar. 2020,

Tetro, JA 2020. Is COVID-19 receiving ADE from other coronaviruses? Microbes and Infection 22:72-73.

More science to explore:

Ahmed SS, Volkmuth W, Duca J. Antibodies to influenza nucleoprotein cross-react with human hypocretin receptor 2. Sci Transl Med. 2015 Jul 1;7(294):294ra105. doi: 10.1126/scitranslmed.aab2354.

Agrawal AS, Tao X, Algaissi A. Immunization with inactivated Middle East Respiratory Syndrome coronavirus vaccine leads to lung immunopathology on challenge with live virus. Hum Vaccin Immunother. 2016 Sep;12(9):2351-6. doi: 10.1080/21645515.2016.1177688. Epub 2016 Jun 7.

Deming D, Sheahan T, Heise M. 2006. Vaccine efficacy in senescent mice challenged with recombinant SARS-CoV bearing epidemic and zoonotic spike variants. PLoS Med. 2006 Dec;3(12):e525.

Gretebeck, Lisa M, and Kanta Subbarao. “Animal models for SARS and MERS coronaviruses.” Current opinion in virology vol. 13 (2015): 123-9. doi:10.1016/j.coviro.2015.06.009


“Safety and Immunogenicity Study of 2019-NCoV Vaccine (MRNA-1273) to Prevent SARS-CoV-2 Infection – Full Text View.” Full Text View –,

Tetro, JA 2020. Is COVID-19 receiving ADE from other coronaviruses? Microbes and Infection 22:72-73.

Weingartl H, Czub M, Czub S, Immunization with modified vaccinia virus Ankara-based recombinant vaccine against severe acute respiratory syndrome is associated with enhanced hepatitis in ferrets. J Virol. 2004 Nov;78(22):12672-6.

Yong, Chean Yeah, et al. “Recent Advances in the Vaccine Development Against Middle East Respiratory Syndrome-Coronavirus.” Frontiers in Microbiology, Frontiers Media S.A., 2 Aug. 2019,