COVID-19 Vaccines: Real-World Effectiveness / CDC Director's Warning / Practical Considerations

By Amy Orciari Herman

Edited by David G. Fairchild, MD, MPH, and Jaye Elizabeth Hefner, MD

In the United States, the real-world effectiveness of the COVID-19 mRNA vaccines is 90%, CDC researchers reported in MMWR on Monday.

Some 4000 healthcare workers, first responders, and other essential or frontline workers from eight U.S. locations self-collected nasal swabs for SARS-CoV-2 PCR testing each week, regardless of symptoms, between mid-December and mid-March. Those with prior evidence of SARS-CoV-2 infection were excluded.

Some 63% of participants received two doses of mRNA vaccine, and 12% received one dose, during the study period. The incidence rate of confirmed SARS-CoV-2 infection was 1.38 per 1000 person-days in unvaccinated people, 0.19 per 1000 in partially vaccinated people (≥14 days after the first dose and before the second), and 0.04 per 1000 in fully vaccinated people (≥14 days after second dose). This translated to an effectiveness of 80% for partial vaccination and 90% for full vaccination.

Also on Monday, CDC director Dr. Rochelle Walensky urged Americans to get vaccinated once they are eligible. In a White House briefing, she said she has a "recurring feeling" of "impending doom" as COVID-19 case counts and hospitalizations show an uptick. In particular, case counts have increased by 16% compared with a week ago, and hospitalizations have increased by 4%, CNBC news reports.

Separately, the Annals of Internal Medicine and the American College of Physicians have posted a forum on practical considerations with the COVID-19 vaccines. Among the panelists are NEJM Journal Watch's Dr. Carlos del Rio and Dr. Paul Sax. Take a look at the link below.