How safe will you be if you get the Moderna “95%-effective” vaccine?
Pfizer and Moderna have announced impressive-sounding effectiveness figures for their revolutionary vaccines. These mRNA vaccines, instead of injecting a weakened virus, use a genetically engineered messenger RNA that turns your own cells into vaccine factories. You make viral spike proteins, then your immune system makes antibodies to this foreign protein. The idea is that the antibodies will attach to the virus so it can’t enter your cells. Or that your killer T-cells will recognize the spikey virus and destroy it.
Ingenious—but novel and minimally tested.
You may think that “95% effective” means that you are almost completely protected if you come in contact with the virus. Not exactly. It means that so far 90 of confirmed COVID-19 cases in 30,000 study participants were in the placebo group, including the 11 “severe” cases, and only five were in the vaccinated group. The other 29,900 or so haven’t gotten infected yet, vaccinated or not.
Moderna is applying for an Emergency Use Authorization (EUA) to roll out the vaccine. It could be that you will have to have proof of vaccination to travel, work, or go to school.
Things we don’t know:
- Will my vaccine protect you? There is no evidence that the vaccine prevents infection or transmission. If it just reduces or eliminates symptoms, the vaccinated person is more likely to be out interacting with people instead of being home in bed.
- Will there be late or rare side effects? We won’t know until months or years after millions of doses have been given.
- How will it affect fertility, or the health of offspring? It is too soon to say. Remember that genetically modified foreign genetic material is being incorporated into your cells. Should old people and men get it first?
- Might antibody-dependent enhancement of disease be a problem? This is always a concern in vaccine development and is unpredictable.
- How long will protection last? Is it more or less robust than natural immunity? It is again too early to say.
As the graphic below illustrates, COVID-19 (striped circle in the foreground) is relatively insignificant in the history of plagues. The only one in which vaccination played a significant role was smallpox.
What you can do now: