That’s a particularly apt comparison. Here’s why:
Like a lot of compounds, Thalidomide is “chiral”, or “handed”. There are two versions of the molecule that are mirror images of each other. It’s thought that only one of these “mirror images” caused the problems with Thalidomide (there’s more to it, but that’s the gist.)
Drug companies and researchers are all over chirlatity today, largely as a result of the Thalidomide mess, but in 1957, when the drug was approved for use in Europe, they didn’t really pay any attention to “handedness”...it was known to exist, but not thought to be important. Now we know, and 10,000 people in Europe and the UK paid the price.
So, here’s the question: what don’t we know about mRNA used as a vaccine? This will be widely distributed, so we’ll know some of the answers to that pretty soon, and probably know a lot more after a couple of years.
For myself, I’m not at all unhappy that I won’t be in the first or second tranche of people eligible for the shot. I’ll evaluate the risks at that point after a few million folks have offered up their arms as test subjects.
We know pretty much everything there is to know about mRNA. It’s a polynucleotide that occurs in every cell in every living organism, including humans. It functions as a “messenger” (hence the “m”) that transfers genetic information from the DNA in the nucleus to the ribosomes, structures in the cell where protein synthesis occurs. The mRNA consists of a sequence of nucleotide bases that are complementary to the ones in the DNA. Molecules of tRNA pair with the mRNA at the ribosome. Each tRNA is 3 bases long and each binds to a specific amino acid. In this way, the proper sequence of amino acids is assembled into a protein.
The vaccine has an mRNA sequence that doesn’t match any human DNA sequence. It therefore encodes a protein that is not normally synthesized by humans, namely the spike protein of the virus. This stimulates the immune response and provides immunity from the virus. It is not possible for someone to be allergic to mRNA. The reactions have been to other ingredients in the vaccine and are similar to those that occur with other vaccines. They are not from mRNA.