COVID-19 vaccine shows promise in mouse studies
Vaccine currently being evaluated in Phase 3 clinical testing

Date:
August 5, 2020
Source:
NIH/National Institute of Allergy and Infectious Diseases
Summary:
A new study has found that the investigational vaccine known as
mRNA-1273 protected mice from infection with SARS-CoV-2, the virus
that causes COVID-19.



FULL STORY ==========================================================================
The investigational vaccine known as mRNA-1273 protected mice from
infection with SARS-CoV-2, the virus that causes COVID-19, according to research published today in Nature.


========================================================================== Scientists at the National Institute of Allergy and Infectious
Diseases (NIAID), part of the National Institutes of Health, and the biotechnology company Moderna, based in Cambridge, Massachusetts, along
with collaborators from the University of North Carolina at Chapel Hill, Vanderbilt University Medical Center in Nashville, and the University
of Texas at Austin conducted the preclinical research. NIAID Vaccine
Research Center (VRC) scientists worked with investigators from the
University of Texas at Austin to identify the atomic structure of the
spike protein on the surface of the novel coronavirus.

This structure was used by VRC and Moderna in the development of the
vaccine candidate.

The findings show that the investigational vaccine induced neutralizing antibodies in mice when given as two intramuscular injections of a
1-microgram (mcg) dose three weeks apart. Additional experiments found
that mice given two injections of the 1-mcg dose and later challenged
with SARS-CoV-2 virus either 5 or 13 weeks after the second injection
were protected from viral replication in the lungs and nose. Importantly,
mice challenged 7 weeks after only a single dose of 1 mcg or 10 mcg of mRNA-1273 were also protected against viral replication in the lung.

The investigational vaccine also induced robust CD8 T-cell responses
in mice.

It did not induce the type of cellular immune response that has been
linked to vaccine-associated enhanced respiratory disease (VAERD). This
rare, allergic- type inflammation was seen in individuals vaccinated with
a whole-inactivated respiratory syncytial virus (RSV) vaccine in the
1960s. VAERD can occur when a vaccine induces an immune response that
is not strong enough to protect against infection. The investigators
vaccinated mice with sub-protective doses of mRNA- 1273 and then
challenged the mice with SARS-CoV-2. The mice showed no evidence of
enhanced lung pathology or excessive mucus production, indicating the
vaccine did not cause enhanced disease, the authors write.

The authors note that the data from these studies, combined with
data from studies in nonhuman primates and Phase 1 clinical testing,
support the evaluation of mRNA-1273 in clinical efficacy trials. They
also explain how their prior research on a candidate MERS-CoV vaccine
paved the way for a rapid response to the COVID-19 outbreak. "This is a demonstration of how the power of new technology-driven concepts like
synthetic vaccinology facilitates a vaccine development program that
can be initiated with pathogen sequences alone," the authors write.


========================================================================== Story Source: Materials provided by NIH/National_Institute_of_Allergy_and_Infectious Diseases. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Kizzmekia S. Corbett, Darin K. Edwards, Sarah R. Leist, Olubukola M.

Abiona, Seyhan Boyoglu-Barnum, Rebecca A. Gillespie, Sunny Himansu,
Alexandra Scha"fer, Cynthia T. Ziwawo, Anthony T. DiPiazza,
Kenneth H.

Dinnon, Sayda M. Elbashir, Christine A. Shaw, Angela Woods, Ethan J.

Fritch, David R. Martinez, Kevin W. Bock, Mahnaz Minai, Bianca
M. Nagata, Geoffrey B. Hutchinson, Kai Wu, Carole Henry, Kapil
Bahi, Dario Garcia- Dominguez, LingZhi Ma, Isabella Renzi,
Wing-Pui Kong, Stephen D. Schmidt, Lingshu Wang, Yi Zhang, Emily
Phung, Lauren A. Chang, Rebecca J. Loomis, Nedim Emil Altaras,
Elisabeth Narayanan, Mihir Metkar, Vlad Presnyak, Cuiping Liu,
Mark K. Louder, Wei Shi, Kwanyee Leung, Eun Sung Yang, Ande West,
Kendra L. Gully, Laura J. Stevens, Nianshuang Wang, Daniel Wrapp,
Nicole A. Doria-Rose, Guillaume Stewart-Jones, Hamilton Bennett,
Gabriela S. Alvarado, Martha C. Nason, Tracy J. Ruckwardt, Jason
S. McLellan, Mark R. Denison, James D. Chappell, Ian N. Moore,
Kaitlyn M. Morabito, John R.

Mascola, Ralph S. Baric, Andrea Carfi, Barney S. Graham. SARS-CoV-2
mRNA vaccine design enabled by prototype pathogen
preparedness. Nature, 2020; DOI: 10.1038/s41586-020-2622-0 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200805102036.htm

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