Two doses of Moderna’s coronavirus vaccine-protected mice from infection for 13 weeks – and a single shot blocked the virus for 7 weeks
- Modern vaccines trick the body into producing some of the viral proteins, which the immune system recognizes and builds a response to mice
- Researchers gave mice two intramuscular doses, one microgram each, at three-week intervals
- The rodents were exposed to the virus five weeks and 13 weeks after the second injection, but never became ill.
- After mice were given only one dose and then exposed to the virus seven weeks later, they still did not become ill
Modern experimental coronavirus vaccine-protected mice from infection for several weeks, the results published on Wednesday show.
Researchers found that the rodents received two doses of the immunization, they were protected for at least 13 weeks.
Findings also show that, if given insufficient doses, “jab” did not “strengthen” COVID-19, the disease caused by the virus, in mice.
It comes as Health and Human Services Secretary Alex Azar called the recent inoculation development of coronavirus over the past two weeks “the most historic progress in vaccine development” in an interview with Fox News.
Modern vaccines (above) trick the body into producing some of the viral proteins, which the immune system recognizes and builds a response to mice
Mice were given two intramuscular doses three weeks apart and then exposed to the virus five and 13 weeks later, but the mice did not become ill (above) due to neutralizing antibodies.
The vaccine, developed by Massachusetts-based Modern, was developed in collaboration with the National Institutes of Health.
mRNA-1273 works by tricking the body into producing some of the viral proteins, which the immune system then recognizes and builds a defensive response against.
For the study, published in the journal Nature, the team gave mice two intramuscular doses, one microgram each, at three-week intervals.
The rodents were then introduced into the virus either five weeks or 13 weeks after the second injection.
Mice did not become ill if they were exposed one month after inoculation or three months thereafter.
In addition, mice given a dose of the vaccine and then exposed to the virus seven weeks later had no pathogens in the lungs.
Inoculation also increased a response in mice of CD8-T cells, which are important for killing cells infected with cancer or viruses.
The researchers then inoculated the mice with insufficient doses and then introduced them to the coronavirus to see if they would develop vaccine-associated respiratory distress disease (VAERD).
VAERD occurs when a vaccine induces an insufficient immune response to prevent infection, such as what happened to individuals receiving RSV jab in the 1960s.
The mice had no signs of pneumonia or excess mucus production, which the team says means that the inadequate vaccine did not “strengthen” the disease.
The authors add that data from this study, in combination with findings from other studies in humans, suggest further investigation of mRNA-1273.
“This is a demonstration of how the power of new technology-driven concepts such as synthetic vaccinology facilitates a vaccine development program that can be initiated with pathogen sequences alone,” they wrote.
According to the World Health Organization, more than 100 COVID-19 vaccines are under development around the world and at least 23 are in human trials.
In the United States, there are more than 4.7 million confirmed cases of the virus and more than 156,000 deaths.