“Antibodies produced by vaccinated and boosted people may not stop omicron SARS-CoV-2 strain from entering cells as well as it stops original virus,” say Johns Hopkins researchers.
QUICK FACTS:
- Researchers at Johns Hopkins Medicine and the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH) recently found that antibodies that might work against the original strain of SARS-CoV-2 don’t do as well in preventing the new omicron coronavirus strain, and possibly older strains, from infecting healthy cells.
- The study‘s senior author, Joel Blankson, M.D., Ph.D., professor of medicine at the Johns Hopkins University School of Medicine, said that while antibodies produced from the vaccine are able to stop viruses from successfully binding to certain enzymes in the body, those same vaccine-induced antibodies are not able to stop new COVID variants from binding to those enzymes.
- “Previous research has shown vaccine-induced antibodies respond to the original strain of SARS-CoV-2 by inhibiting the virus’s ability to bind to angiotensin-converting enzyme 2 [commonly known as ACE2], the receptor on a cell’s surface through which SARS-CoV-2 gains entry,” said Dr. Blankson. “Our study suggests those same antibodies yield less ACE2 inhibition with the omicron strain, opening the door to a breakthrough COVID-19 infection.”
- It is not clear from the study precisely how much weaker COVID vaccines are against new virus strains, but only that vaccine effectiveness is “reduced.”
- However, the researchers were “not able to document” exactly which strain of coronavirus, old or new, the breakthrough infections they studied were caused by, arguing only that there was “a strong probability” the infections were caused by a new omicron strain.
- “Although the researchers were not able to document that the breakthrough infections were from the omicron strain, they say it’s a strong probability because the omicron variant accounted for more than 90% of the COVID-19 cases treated at The Johns Hopkins Hospital (where the study was conducted) during the time when the study participants became symptomatic,” the study’s news release explained.
- But by that measure, 10% of breakthrough infections were from earlier coronavirus strains.
JOHNS HOPKINS STUDY CONCLUSION:
“Our data suggest that breakthrough infections with the Omicron variant can occur despite robust immune responses to the vaccine strain spike protein,” the study concluded.
READ THE STUDY:
Johns-Hopkins-SARS-CoV-2-specific-immune-responses-in-boosted-vaccine-recipients-with-breakthrough-infections-during-the-Omicron-variant-surgeDownload
BACKGROUND:
- The Johns Hopkins study was first posted online on April 7, 2022, in the peer-reviewed Journal of Clinical Investigation Insights (JCI).
- In the study, Blankson and colleagues analyzed 18 healthy individuals who were fully vaccinated and yet still became infected with covid 14 to 92 days after receiving a booster COVID-19 vaccine.
- Fourteen participants had taken a booster of the Pfizer-BioNTech messenger RNA (mRNA) vaccine, while one was boosted with the Moderna mRNA vaccine, and the last three had an mRNA booster following their initial dose of the Johnson & Johnson viral vector vaccine.
