COVID-19 Risk in Vaccinated Healthcare Workers

Vaccinated healthcare workers have a risk of being infected with SARS-CoV-2 of about 1%, a rate that is much higher than that reported in clinical studies.

Riesgo de COVID-19 en trabajadores de salud vacunados

Multiple reasons can explain this difference. However, emphasis should be placed on the paramount importance of protective measures, such as wearing a facemask, social distancing, daily symptom checking, and regular testing.

Papers published in the New England Journal of Medicine (NEJM) on the two messenger RNA vaccines—Pfizer’s and Moderna’s—showed an efficacy of 95% and 94.1%, respectively, in preventing symptomatic COVID-19 cases at 7 (Pfizer) and 14 (Moderna) days after the second dose.

Healthcare workers at two California Universities (San Diego and Los Angeles) began vaccination in December 2020 along with a very-low-threshold strategy that required testing after the slightest of symptoms and a systematic search for asymptomatic cases with a weekly PCR testing.

Between December 2020 and February 2021, about 21,184 workers received both doses of one of these messenger RNA vaccines.

Only 8 individuals had a positive PCR test result between 8 and 14 days after the second dose, and only 7 beyond 15 days.


Read also: Primary COVID-19 Infection Protects Against Potential Reinfection?


In this cohort, the absolute risk of testing positive for SARS-CoV-2 was 1.19% in San Diego, and 0.97% in Los Angeles.

These risk rates are above those reported in both published papers on the efficacy of these vaccines. Multiple explanations may arise, but the two most obvious are extensive testing to diagnose asymptomatic patients and higher exposure to the virus compared with the general study population.

These data support vaccine efficacy, but also make clear the importance of maintaining all protective measures.

nejm-infección-post-vacuna-free

Original Title: SARS-CoV-2 Infection after Vaccination in Health Care Workers in California.

Reference: Jocelyn Keehner et al. N Engl J Med. 2021 May 6;384(18):1774-1775. doi: 10.1056/NEJMc2101927.


Subscribe to our weekly newsletter

Get the latest scientific articles on interventional cardiology

More articles by this author

Is the Booster Dose Against COVID-19 Effective for All Ages?

The answer is incontrovertible: it is undeniably effective. For all ages, the confirmed COVID19 and severe case rates were significantly lower for patients who...

Pfizer Booster Dose Efficacy against Omicron

The BNT162b2 vaccine (Pfizer/BioNTech) has previously shown a 95% efficacy against COVID-19. This efficacy has been changing with the surge of new variants and,...

Once Again, the Omicron Variant Tests the Limits of Healthcare Systems, But with Hope

The latest significant COVID-19 variant, the Omicron, is again pushing healthcare systems around the world onto the verge of collapse, having reached over 300...

The Most Read Articles of 2021: COVID-19

A new year is coming to an end and at SOLACI we are going over the most read studies on our website, on COVID-19. Follow...

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Related Articles

SOLACI Sessionsspot_img

Recent Articles

TCT 2024 | FAVOR III EUROPA

The study FAVOR III EUROPA, a randomized trial, included 2,000 patients with chronic coronary syndrome, or stabilized acute coronary syndrome, and intermediate lesions. 1,008...

TCT 2024 | TRISCEND II

This randomized study included 400 patients; 267 were treated with EVOQUE valve and 133 with optimal medical treatment (OMT). After one-year follow-up, there were no...

TCT 2024 – ACCESS-TAVI: Comparing Percutaneous Access Closure Strategies After TAVI

Vascular access complications following transcatheter aortic valve implantation (TAVI) remain common. However, few studies compare vascular access closure methods.  Based on the CHOICE-CLOSURE and MASH...