To the Editor
Of their article on breakthrough infections amongst well being care employees who had been absolutely vaccinated in opposition to extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) an infection, Bergwerk and colleagues (revealed on-line on July 28)1 report that amongst 1497 such employees for whom polymerase-chain-reaction (PCR) information have been accessible, 39 breakthrough infections have been documented at their facility. There have been no instances of secondary transmission amongst 31 of the employees with breakthrough instances who had accessible information relating to family transmission.
Since March 2021, we have now recognized 4 breakthrough infections amongst 8678 absolutely vaccinated well being care employees at Asan Medical Middle. All 4 of the employees had obtained two doses of the ChAdOx1 nCoV-19 vaccine (Oxford–AstraZeneca) inside a 12-week interval. The median interval between the receipt of the second dose of vaccine and analysis was 37 days (vary, 29 to 42), and the median cycle threshold (Ct) on the STANDARD M nCoV Actual-Time Detection Package (SD Biosensor) was 13.1 (vary, 12.3 to 16.0).
On the premise of epidemiologic investigation and speak to tracing, we decided that three of the employees had been contaminated by publicity to unvaccinated family members, and the remaining employee (HCW B) had been contaminated by one other vaccinated well being care employee (HCW A), who in flip had contracted a breakthrough an infection from her unvaccinated partner. (HCWs A and B had eaten a meal collectively and talked with out carrying a masks for 20 minutes 1 day earlier than the an infection was identified in HCW A; 5 days later, signs developed in HCW B.) PCR evaluation with the usage of the Kaira COVID-19 Variant Detection Package (Optolane) revealed the presence of both the eta variant or the zeta variant (with out sensitivity for additional differentiation) in each well being care employees. Though in our hospital breakthrough instances have been uncommon, viral masses amongst these instances have been reasonable. Thus, our findings present that the transmission of SARS-CoV-2 between vaccinated individuals is feasible.
Jiwon Jung, M.D.
Heungsup Sung, M.D.
Sung-Han Kim, M.D.
Asan Medical Middle, Seoul, South Korea
[email protected]
No potential battle of curiosity related to this letter was reported.
This letter was revealed on September 29, 2021, at NEJM.org.
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1. Bergwerk M, Gonen T, Lustig Y, et al. Covid-19 breakthrough infections in vaccinated well being care employees. N Engl J Med. DOI: 10.1056/NEJMoa2109072.
Response
For 120 of the employees with breakthrough infections, the indication for testing was recognized. The bulk (85 employees) have been examined due to signs; 35 have been asymptomatic on the time of testing, and none required hospitalization. Among the many 61 employees who had an recognized suspected supply of an infection, 37 of such contacts (61%) had been absolutely vaccinated, together with 15 fellow well being care employees, 21 family or neighborhood contacts, and 1 hospitalized affected person. Among the many 80 employees with breakthrough an infection for whom information have been accessible, the median worth for the bottom N-gene Ct worth was 22 (vary, 14 to 38), which was thought-about to point a excessive diploma of infectivity.1,2 Of the 84 samples that have been analyzed by rapid-antigen assays, solely 44 examined constructive.
In our findings involving well being care employees who had obtained two doses of the BNT162b2 vaccine greater than 6 months earlier, many breakthrough infections with the delta variant (each symptomatic and asymptomatic) have been related to a excessive viral load and the attainable transmission of secondary an infection. These findings name for additional rigorous preventive measures, similar to booster vaccinations, in-hospital social distancing, in depth use of private protecting tools, considered out-of-hospital conduct, and frequent molecular testing after the prevalence of signs or recognized publicity to contaminated contacts.
Sharon Amit, M.D., Ph.D.
Tal Gonen, B.A.
Gili Regev-Yochay, M.D.
Sheba Medical Middle, Ramat Gan, Israel
[email protected]
Since publication of their article, the authors report no additional potential battle of curiosity.
This letter was revealed on September 29, 2021, at NEJM.org.
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1. Jefferson T, Spencer EA, Brassey J, Heneghan C. Viral cultures for COVID-19 infectious potential evaluation — a scientific evaluation. Clin Infect Dis 2020 December 3 (Epub forward of print).
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2. Singanayagam A, Patel M, Charlett A, et al. Period of infectiousness and correlation with RT-PCR cycle threshold values in instances of COVID-19, England, January to Might 2020. Euro Surveill 2020;25:2001483–2001483.
