With the shipment of the Johnson and Johnson/Janssen vaccine now available throughout the U.S., in addition to the earlier release of the Pfizer and Moderna vaccines, we would like to share data that corrects a misperception about vaccine efficacy that may lead to vaccine hesitancy or postponement by patients.
As with the mRNA-based vaccines (Pfizer and Moderna), the viral vector-based J&J/Janssen vaccine is highly effective, with an 85% efficacy rate of preventing severe symptoms. As the clinical trials periods of the J&J vaccine was run to a later end date (when new variants were beginning circulation) than the mRNA vaccines, the results are not directly comparable. We encourage all USC employees and eligible students who meet current criteria to pursue avenues throughout the County and the public sites to get vaccinated at the earliest availability.
Brief facts are below:
Vaccination will be offered with the newly available single-dose vaccination (Johnson & Johnson or J&J/Janssen). This vaccine does not require return to clinic for a second dose. A few notes about the J&J/Janssen vaccine:
- After 4 weeks, in clinical trials the J&J vaccine was shown to be 66% effective at preventing coronavirus infections altogether and 85% effective at preventing severe COVID-19 cases.
- Of the trial participants who did test positive for COVID-19 after receiving the J&J/Janssen vaccine, zero had to be hospitalized.
- Early evidence suggests that the J&J/Janssen vaccine provides protection against asymptomatic infection as well.
- Common side effects of all COVID-19 vaccines include pain, redness, and swelling at the vaccine site and tiredness, headache, muscle pain, chills, fever and nausea. These are more common after the second dose of vaccine (for vaccines that require a second dose) and therefore side effects may be less common with the J&J/Janssen vaccine as only one dose is required.
- In trials, the J&J/Janssen vaccine efficacy varied geographically and was highest in the United States at 74.4%.
- Which vaccine is right for me? All of them — they are all clinically proven to prevent severe illness, hospitalization, and fatalities.