The mRNA molecule makes us a drug factory

Roughly two years ago, an obscure news story that most of us understandably missed provided a first glimpse of the science involved in carefully designing molecules called messenger RNA (mRNA), which uniquely prompt the body to make its own medicine. A biotech event in Cambridge, Mass., hosted by Moderna Therapeutics, a company that most of us had never heard of but has since become famous, took the wraps off mRNA. As Moderna president Stephen Hoge explained to his enthralled audience: “…all life that we know flows through messenger RNA. . . . In our language, mRNA is the software of life.”

Hoge went on to explain that cells use mRNA to translate the genes of DNA into proteins. These proteins are involved in every bodily function. Normally, biotech companies produce many of these proteins as drugs and indeed stockpile them in large vats for eventual distribution. But what if mRNA could be therapeutically introduced into people’s bodies in ways that put the drug factory inside each one of them?

While the idea, of course, is conceptually very appealing, implementation is not. The key problem and challenge for biotechnology is that when mRNA is injected into the body, it triggers sensors that nature designed to guard the body against viruses. These virus-detecting sensors cause cells to shut down protein production. Thus, doing their genetic job, the sensors foil therapy. But what if an mRNA molecule somehow makes it into a cell? The mRNA might not make enough protein to actually fulfill its therapeutic mission.

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The Vaccine Race: Science, Politics, and the Human Costs of Defeating Disease by Meredith Wadman

How a successful COVID-19 vaccine would work

By ARNOLD SCHUCHTER, St. James Faith Lab Tech Editor

Every day we read stories about the relentless efforts of scientists to get the upper hand on the coronavirus by developing an effective vaccine. The successful vaccine will arm the body's immune system. The key to these efforts is understanding how our immune system works and especially its two very important cells that collaborate together: B cells and T cells. The most important thing to know about various types of T cells is that (thank goodness) they directly kill infected cells and also help B cells to succeed. How? By releasing chemical signals (“cytokines”) that transform B cells into plasma cells that produce antibodies that in turn neutralize pathogens.

T cells get all the credit for vanquishing viral and bacterial invaders. Once vanquished, a pool of T and B cells continue, let’s say, in the body’s “memory.” The cells remain dormant until the next encounter with the same pathogen. When that happens, they can produce a much faster and stronger immune reaction. Since most of us have not been exposed to the “novel coronavirus,” we have no T and B cells in memory and, therefore, no special protection against COVID-19. As for the millions of people who have recovered from COVID-19, scientists are still trying to learn exactly how their immune systems will respond to the next encounter with infected people. In other words, how effective are T and B cells in memory for preventing recurrent episodes of COVID-19?

Is herd immunity the answer to preventing reinfection? Herd immunity is the point when a large portion of the population is immune, making it harder for the virus to circulate widely. Estimates on the percentage of the population that must be immune to SARS-CoV-2 to achieve “herd immunity” range from 40 to 80 percent. There isn’t a consensus of when the United States may reach this threshold. But the outbreaks, hospitalizations, and deaths from the virus in Florida, Texas, and Arizona should make it clear that the human costs of achieving herd immunity can be substantial. Obviously we need a vaccine to achieve population immunity in a fashion that doesn’t kill people or destroy their health.

Following vaccines in development can be an exhausting process. There are about 170 vaccines being tested in-lab and on animals. About seven are being tested for safety in just a small number of young people. About 12 vaccines already are in Phase II tests in people at a higher risk of illness. Another seven vaccines are in Phase III tests aiming for thousands of people. Pfizer has dosed 11,000 out of its targeted 30,000. Moderna is slightly ahead with about 13,000 participants out of 30,000. St. James Faith Lab will keep everyone up-to-date on vaccine development testing and progress.