The last week of the fall semester provided me with an opportunity to design whatever I wanted for my Biology and Biotechnology classes. Long story short, we were not going to have a true final exam period and we were wrapping up units the week before. In both cases, I decided to teach about viruses, the immune system, and COVID.
As part of the unit, I showed a NOVA video entitled “Calling the Shots” that talks about vaccines – their history and why some people are “vaccine hesitant.” I highly recommend tis video. It was produced before the pandemic so the focus is on why measles and whooping cough are making a return. Again, pre-pandemic, but so many parallels to some people’s concerns regarding vaccines against SARS-CoV-2.
Calling the Shots includes discussion of why people are hesitant to be vaccinated and it is in this section where, sometimes, there are granules of truths in myths.
Myth #1 – COVID vaccines can cause COVID. We know they cannot. In particular, the Moderna and Pfizer vaccines only encode the spike protein, not the entire virus, and any rise in body temperature is just the body’s natural immune response. So where does this idea come from?
The video reminds us that some vaccines in the past have caused disease. One particular example is the oral polio vaccine. This version contained a weakened version of the polio virus, but in very rare cases (1 in 2.4 million doses) it could mutate into a version that could cause polio. In the 1950’s and 60’s, this was an acceptable risk as tens of thousands of children were afflicted with this disease.
As rates of polio dropped significantly, there was actually a higher chance of developing polio from the oral vaccine than from coming in contact with someone with polio so that version of the vaccine is no longer used. Again, this is not possible with any of the COVID vaccines.
Myth #2 – COVID vaccines lead to infertility. Again, we know this is not the case. While pregnant women were not intentionally part of the initial studies of vaccine effectiveness, some did become pregnant during the study and many more women have been able to become pregnant and have babies after being vaccinated. There does not appear to be an increase in miscarriages due to COVID vaccines so where did this idea come from?
As it turns out, there is a protein on the surface of blastocysts called Syncytin-1. This protein allows the blastocyst to attach to the uterine lining. If you align the amino acid sequence of Syncytin-1 with the SARS-CoV-2 spike protein, there are 4 amino acids which are identical (2 valines, a different amino acid, followed by Glutamine and Asparagine). Out of over 1000 amino acids in the spike protein, that’s all.
The concern would be that antibodies against the spike protein would also bind to the Syncytin-1 protein and result in a miscarriage. However, there just isn’t enough similarity between these two proteins for antibodies against the spike protein to get confused. One analogy I read described it as mistaking a cat for an elephant because they are both gray.
[By the way, you really should look up the origin of the Syncytin-1 gene. It originated from a retrovirus and is just one example of how significant amounts of our DNA is not really ours, but viral. The appearance of this gene in the genome coincides with the transition of some organisms (mammals included) from egg laying to those that have a placenta. Really cool.]
Myth #3 – COVID vaccines genetically engineer your DNA. One more time, not true. The vaccine does have RNA which is a type of genetic material. The ribosomes in your cells do use the RNA to make the spike protein. However, like all RNA, the RNA for the spike protein does not last forever (approximately a few days). This is in line with other RNA produced by your own body, some of which lasts only a few minutes and others a bit longer. Regardless, the RNA has no way of inserting itself into your chromosomes. We know this because your chromosomes are made of DNA and we do not see alternating DNA and RNA sequences in them. One last time, where does this idea come from?
This might be a little harder to explain because, honestly, I have no idea. However, it might go something like this – SARS-CoV-2 is an RNA virus just like other viruses such as rhinovirus which causes the common cold and HIV which causes AIDS. The difference here is that HIV is a special type of virus called a retrovirus. It encodes a special enzyme called “reverse transcriptase” which it uses to convert its virus RNA into DNA that can then insert itself into a person’s chromosomes where it can stay for quite a period of time. Again, this is for retroviruses like HIV. Coronaviruses like SARS-CoV-2 is not capable of doing reverse transcription and have no way to become part of your DNA. Certainly, the RNA in the vaccine has no way of doing this either.
Perhaps especially those of you in Wisconsin will be interested in the history of reverse transcription. Howard Temin, who did his research at UW-Madison, first proposed the idea of a reverse transcription. There was a lot of doubt about this idea (to put it lightly) as it was strongly believed that all organisms followed the Central Dogma of Molecular Biology – DNA to RNA to protein. His persistence paid off with the amazing discovery of the reverse transcriptase enzyme and he was awarded the Nobel Prize in 1975. UW has honored him by naming the Lakeshore Path, which runs from Memorial Union to Picnic Point, after him.
In each of the above myths (and there are more with other vaccines, watch the video), sometimes there are granules of truths. It is so important as science teachers for us to address these misconceptions and to do so in a way which goes beyond simply saying “not true.” Because we teach science, we should be adding “. . . and here is our evidence.” I think it leads to a deeper understanding that contributes to correcting some of those misconceptions and myths.
Until next month…