Capt. Janell Routh, MD, MHS, Co-Deputy, Vaccine Implementation Unit, Vaccine Task Force, Centers for Disease Control and Prevention presented current knowledge on vaccine safety and efficacy in a recent webinar hosted by The American Journal of Nursing. The following Table provides a quick reference that you can use with your patients when discussing the facts regarding the COVID-19 vaccines.

The CDC also has communication toolkits for health care providers to help boost vaccine confidence. Nursing experts at the webinar also discussed strategies to reduce vaccine hesitancy and access barriers in Black, Hispanic, Orthodox Jewish, and other underserved communities. Click here to read more.

Table. COVID-19 Vaccine Fast Facts

Pfizer-BioNTech and Moderna COVID-19 vaccines
• The vaccines were tested in tens of thousands of people of diverse backgrounds, including people of color
• Both vaccines are 95% effective at preventing COVID-19 infection after 2 doses
• These mRNA vaccines carry genetic material from the virus that cause the body to make a “spike protein” that is found on the surface of the SARS-CoV-2 virus; the immune system makes antibodies against the spike protein to protect against infection if SARS-CoV-2 enters the body
– This genetic material is destroyed by the body once copies of the spike protein are made
– The vaccines do not affect or interact with a patient’s DNA
mRNA vaccine development
• mRNA technology has been studied for more than 10 years
• Researchers used existing trial networks to test the vaccines
• mRNA vaccines are faster to produce than traditional vaccines
• Given the unique circumstances of the COVID-19 pandemic, manufacturing began while clinical trials were ongoing, allowing the vaccines to become available relatively quickly
mRNA vaccine safety data
• Side effects are typically self-limited and resolve in 1-2 days
• Side effects are caused by the body’s immune response to the vaccine
• Using v-safe data, pain is the most common reaction to the Pfizer-BioNTech and Moderna vaccines (approximately 68%-70%), followed by fatigue, headache, myalgia, chills, and fevera
• Using VAERS data, there were 372 adverse events per million doses administered
• Headache is the most common adverse event with both vaccines (21%)
– Of the 372 AEs reported, 22% and 8% were serious with the Moderna and Pfizer-BioNTech vaccines, respectively 
– For the Pfizer-BioNTech vaccine, side effects are typically more common after the second dose than after the first dose
– Safety data is evolving as the vaccines were approved under Emergency Use Authorization and clinical trials are ongoing
Johnson & Johnson’s Janssen COVID-19 vaccine
• 66% to 74% effective at preventing moderate to severe COVID-19 disease
• 1-dose vaccine
• Viral vector vaccine; a modified version of a different virus is used as a vector to deliver a gene that instructs the body to make a SARS-CoV-2 antigen (spike protein); the antigen triggers the body to produce antibodies to fight SARS-CoV-2
• The genetic material does not integrate into a person’s DNA and cannot cause a viral infection
Protocol After Vaccination
• The CDC is using the smartphone-based v-safe app to monitor for adverse events
– The CDC will send text message check-ins daily the first week after vaccination, weekly through 6 weeks, and then at 3, 6, and 12 months
• The CDC is also using the standard Vaccine Adverse Events Reporting System (VAERS) to monitor adverse events
• It is unclear how long vaccine protection lasts
– No vaccine is 100% effective
– Vaccinated persons should continue to wear masks and follow social distancing protocols
EAU, emergency authorization use
aReports received as of January 18, 2021.


Capt. Janell Routh, MD, MHS. Disseminating Facts, Dispelling Myths – Building COVID Vaccine Confidence in Communities. February 26, 2021.

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Centers for Disease Control and Prevention. Vaccines and immunizations: training and education resources. Accessed March 12, 2021.