Pfizer vs. Moderna - Vaccine Comparison
Similarities
The main similarities that I'm sure you all are familiar with by now is that both Pfizer and Moderna require 2 shots, have similar efficacy rates of 95% and 94% respectively, and provide immunity using the same mechanism - they are both mRNA vaccines. If you'd like to know more information about what exactly an mRNA vaccine is click HERE. Another important similarity is that recent studies have demonstrated that both of these vaccines have similar efficacy rates in providing protection against three of the major COVID variants: the NYC, the South African variant, and the UK variant. New studies are continuously being performed every day, so stay tuned for future updates
Differences
The two major differences that are always brought up with these two vaccines are storage and the length of time between second dose administration:
Pfizer must be stored at significantly colder temperatures than Moderna - usually ranging from -112°F to -76°F whereas the Moderna vaccine is stored in regular refrigerators at around 36°F
The second dose of Pfizer vaccine is administered around 21 days after the first whereas the second dose of Moderna is administered around 28 days. The CDC did release a statement a while back saying that anyone who received the first dose of either vaccine are eligible to get the second dose within a 6 week timeframe
Now let's talk about some lesser known differences between these two vaccines because that's what this post is really all about
Efficacy rates
As we talked about before the two vaccines efficacy rates are 95% for Pfizer and 94% for Moderna. Now according to their respective clinical trials, the 95% efficacy for Pfizer kicks in around 7 days after the second dose whereas the 94% efficacy rate for Moderna kicks in about 14 days after the second dose. In other words, for Pfizer, your vaccine is fully effective 7 days after your second shot and for Moderna it takes 14 days to reach full immunity after your second shot.
Both vaccines have 100% efficacy in preventing death from COVID 19. Pfizer is 100% in preventing hospitalizations and Moderna is about 90%.
According to various studies there is speculations on how well Pfizer and Moderna prevent asymptomatic cases of COVID19, meaning you have COVID but it's not causing any noticeable symptoms in your body. Pfizer is speculated to have about 90% efficacy whereas Moderna has about 66%. However, this data is less concrete than the efficacy rates found in each vaccines clinical trials
Administration
Pfizer's vaccine is only has about 30 micrograms that goes into your body whereas Moderna has 100 micrograms, over 3x the amount of vaccine that Pfizer has. The Pfizer vaccine has to be diluted with saline, so it may appear that the same amount is going into your body, but its actually significantly less than the Moderna vaccine.
Target Population
Both vaccines are undergoing trials to determine the safety and efficacy rates their vaccines would have on younger individuals. For now, Pfizer is approved for individuals age 16+ whereas Moderna is approved age 18+.
