Both the recently announced Pfizer and Moderna COVID-19 vaccines have been developed using messenger RNA technology.

ATHIT PERAWONGMETHA / REUTERS

Vaccines have always been a topic of some controversy.

While there have been some forms of attempted vaccination for centuries, the first scientific use of this technique goes back to 1796 when Edward Jenner, a doctor and scientist, vaccinated a 13-year-old boy with Vaccinia virus, which is responsible for cowpox, a mild infectious illness with low mortality.

In an experiment that appalls us today, Jenner then deliberately infected this young lad with smallpox, one of the most deadly diseases of the time to see if the vaccination protected him. This experiment was not as rash as it would seem as Jenner had noted that milkmaids, who were frequently infected with cowpox, appeared to be immune to smallpox.  Fortunately, for the young man, Jenner’s intuition was correct and the vaccination did indeed give him immunity to smallpox.

Such an experiment would never be allowed today by any ethics board supervising such an experiment. However, the vaccination for smallpox was one of the most successful treatments ever devised and smallpox was eradicated in 1979 after a worldwide campaign to vaccinate everyone. Older people still carry the small scar on their arm from the vaccination.

Vaccination is one of the only defences we have against viruses, which are simple collections of proteins and DNA. There is a lively argument in the biology community if viruses are even alive.

Vaccines for other illnesses had been developed and were in wide use, including defending against cholera, anthrax and the plague.

A virus attaches itself to a cell in your body and drills through the cell wall. It then injects a payload of viral DNA into the cell. It must do this because viruses are so simple that they lack the basic machinery to reproduce themselves. Instead, they hijack the machinery of the host cell and manufacture millions of copies of the viral DNA and proteins. The cell then dies, bursts and releases an army of viral particles that continue the same process until the host kills the infection, or the host dies.

The key to stopping this kind of attack is rapid response. However, it takes time for the body to figure out it is under attack and then manufacture the chemical and biological machinery to fight the infection. Fighting infection is a game of all-out war and often times the body is damaged almost as much as the attacking organism.

Fevers, cough and massive cellular damage can be done in this conflict and sometimes the organism dies in the struggle. The current COVID-19 pandemic has generated research on a scale that has never been seen before. New techniques are being tried that have the potential to cut the development time for vaccines from years to months.

This involves a process using messenger RNA (mRNA) and is one of the hottest areas of biologic development. This works by exploiting cellular machinery to make vaccines. DNA is the blueprint, in a very sloppy sense, of everything that we need to survive. However, DNA does not manufacture the proteins that do the actual work. The DNA acts as a template for the creation of mRNA, which, like a disposable tool, is used by the cells to manufacture proteins. When the process is done, the mRNA is discarded.

Basically, mRNA is acting like a messenger for organelles in the cell, called ribosomes, which read the instructions on the mRNA and make the required proteins. By using this kind of cellular machinery, it is possible to quickly develop proteins that can be used by drug companies to make vaccines. This is much faster than the traditional method of incubating the virus in eggs and waiting for months to get enough to vaccinate the population.

Both the recently announced Pfizer and Moderna COVID-19 vaccines have been developed using mRNA and soon could be ready for distribution. This has been possible only through our mastery of complex biological processes. It is a triumph of science and technology, along with governmental oversight and funding. All testing so far shows the new mRNA vaccines to be safe, effective and easy to manufacture. We may find that life may start returning to normal by next fall. This is a record-breaking pace for vaccine development.

Tim Philp has enjoyed science since he was old enough to read. Having worked in technical fields all his life, he shares his love of science with readers weekly. He can be reached by e-mail at: [email protected].



Source link