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Comparison of Three Coronavirus Vaccines

Mar 10, 2021 4:34 pm

On Feb. 27, the Food and Drug Administration announced it has issued an emergency use authorization for Johnson & Johnson’s one-dose Covid vaccine, making it the third COVID-19 vaccine to be commercially available.  We've compiled a comparison table and some key information relevant to your delivering patient guidance henceforth. 

Key Caveats

  • Important to note that COVID vaccine efficacy varies by country (generally higher in the USA) and with the age group under study (sometimes lower in elderly individuals)
  • None of these are live or replicating vaccines.
Comparison of Pfizer, Moderna and J&J COVID-19 Vaccines
Manufacturer Pfizer Moderna  J&J AstraZenica
EUA approval 12/11/20 12/18/20  2/27/21  Not submitted
Type mRNA mRNA Adenovirus vector Adenovirus (modified)
Number enrolled 43,548 30,420 43,783 NA
# Shots/interval

3 weeks


4 weeks

(2 doses under study)


4-12 weeks

Seroprotection 95%


86% >65yrs

66% Globally

72%   USA

Protection against Severe Dz 92% 88.9% 85%  
Protection from COVID Death 85% (6 deaths) 100% 100%
Protection from COVID Hospitalization 87% 89% 100% 100%
Storage Temp - 94°F -4°F 36°F and 46°F 36°F and 46°F

  • None of these have been studied in children. Pfizer’s vaccine is approved for those over 16 years, while the other 3 have been studied in adults > 18 yrs.
  • None of these have been studied in autoimmune, or immunosuppressed or pregnant individuals
  • "Reactogenicity" (referring to transient mild to moderate adverse effects) may occur in the first 7 days and include: injection site pain, fatigue, headaches, myalgia, arthralgia, flu-like symptoms.
  • With Pfizer and Moderna vaccines, side effects were more common after the second dose.
  • Side effects were more common in younger adults, and less so in older adults
  • Anaphylaxis is exceedingly rare, but occurs usually within 15 min of injection; hence the reason subjects are advised to be observed for a short period after injection.  Reported anaphylaxis rates: Moderna: 2.5 cases per one million doses; Pfizer: 4.7 cases per million doses. Some have suggested that anaphylaxis and more severe reaction are more likely in those with a history of severe allergies or prior anaphylaxis
  • CDC recommends that "if you have had a severe allergic reaction (anaphylaxis) or an immediate allergic reaction—even if it was not severe—to any ingredient in an mRNA COVID-19 vaccine (such as polyethylene glycol), you should not get an mRNA COVID-19 vaccine".
  • Vaccine stability: once the Pfizer vaccine vial has been thawed, it must be used within five days; Moderna’s is stable at fridge temperature for 30 days and at room temperature for 12 hours. J&J’s vaccine can be stored at room temperature for 12 hours d that information
  • There is no data on the durability of protection (how long am I protected?)


The author has no conflicts of interest to disclose related to this subject

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