03/23/2021 (jkzx.com) — Researchers from University of California – San Diego conducted a survey and found covid 19 vaccines made by Moderna and Pfizer may not be as effective as claimed at preventing SARS-CoV-2 infection.
The study published in The New England Journal of Medicine, published online March 23, 2021 shows that up to 1.19% vaccine recipients were diagnosed with SARS-CoV-2 after they received two doses during two weeks after infection of two doses.
The researchers followed up with 36,659 health care workers who were previously vaccinated against SARS-CoV-2 with 28,184 receiving a second shot. The purpose is to see how many still get infected with the covid 19 virus. These workers got shots between between December 16, 2020 and February 9, 2021.
In the group, 379 workers tested positive for SARS-CoV-2 within 14 days after the first injection of a cobid 19 vaccine. After receiving two doses, 37 health care workers tested positive when a maximum immune protection is expected.
The overall SARS-CoV-2 infection rate during the follow-up is 1.19 percent among those receiving covid 19 vaccine from one clinic and 0.97 percent in another both of which are higher than the risk estimated in the vaccine clinical trials.
Lucy E. Horton, MD, MPH, coauthor of the report, associate professor of the University of California – San Diego said the infection risk can have something to do with a regional surge in infections during that period, and young ages of this group which is linked to a greater overall risk of exposure to covid 19.
Although the professor does not mean to suggest the vulnerability of the group to the infection, the statement she made could hint that this group are still at risk of getting covid 19 when exposed to SARS-CoV-2. And they better not get themselves exposed to the virus.
The researchers said the risk for the vaccinated health workers to get infected with covid 19 is rare 14 days after they get the second dose. But they admitted that the risk is not 100%.
There is a possibility that the SARS-CoV-2 infection risk will go up if these subjects were followed up for a longer period.
Previous studies indicated the potency of immunity against SARS-CoV-2 infection can fade away in a matter of months meaning that the actual infection rate of covid 19 can increase among those vaccinated.
該報告的合著者，加利福尼亞大學聖地亞哥分校的副教授露西·霍頓（Lucy E. Horton）是該報告的合著者。與暴露於covid 19的更大總體風險有關。