Researchers have discovered exceptionally potent antibodies that can neutralize virtually all known variants of the COVID-19 virus—including Omicron, a new study shows.
The antibodies, can also neutralize other dangerous animal coronaviruses that could potentially cause future outbreaks.
As reported in Science Advances, the researchers isolated antibodies from the blood of a recovered SARS patient who was thereafter vaccinated against COVID-19. This unique combination of prior coronavirus infection and vaccination generated an extremely broad and powerful antibody response capable of stopping nearly all related coronaviruses tested.
“We sought to address the lack of therapeutic monoclonal antibodies for treatment and prophylaxis of high-risk COVID-19 patients, as all previously approved monoclonal antibodies have lost efficacy against newly emerged SARS-CoV-2 variants,” says senior author Wang Linfa, a world-renowned bat virus expert with the Duke-NUS’ Emerging Infectious Diseases (EID) Programme.
“This work provides encouraging evidence that pan-coronavirus vaccines are possible if they can ‘educate’ the human immune system in the right way.”
The study describes how the researchers obtained six antibodies that could neutralize multiple coronaviruses, including SARS-CoV-2, its variants Alpha, Beta, Gamma, Delta, and Omicron, the original SARS virus, and multiple other animal coronaviruses transmitted from bats and pangolins.
“Three antibodies stood out as exceptionally broad and potent, capable of neutralizing all tested SARS-related viruses at very low concentrations,” says first author Chia Wan Ni, a former postdoctoral fellow in Wang’s lab who now works with Singapore start-up CoV Biotechnology.
The most powerful antibody, named E7, neutralized both SARS-CoV and SARS-CoV-2 sarbecoviruses, animal sarbecoviruses, and newly emerged SARS-CoV-2 variants, such as Omicron XBB.1.16.
It was shown to neutralize via a unique mechanism of binding that bridges two parts of the coronavirus’ spike protein that it uses to invade cells. This appears to lock the spike in an inactive conformation and block the shape-shifting process the virus requires to infect cells and cause illness.
“The neutralizing potency and breadth of the E7 antibody exceeded any other SARS-related coronavirus antibodies we’ve come across,” Chia says. “It maintained activity against even the newest Omicron subvariants, while most other antibodies lose effectiveness.”
The findings help unmask the weak spots of coronaviruses and provide templates for designing vaccines and drugs that work against COVID-19 variants and future coronavirus threats.
“This work demonstrates that induction of broad sarbecovirus-neutralizing antibodies is possible—it just needs the right immunogenic sequence and method of delivery,” Wang says. “This provides hope that the design of a universal coronavirus vaccine is achievable.”
With its high potential to neutralize sarbecoviruses that emerge in the future, the E7 antibody may become a strong asset in helping to prevent the next pandemic caused by sarbecoviruses. The researchers plan to further assess the antibody’s potential as a prophylactic and therapeutic agent against existing and future coronaviruses.
Additional coauthors are from the University of Melbourne in Australia, the Fred Hutchinson Cancer Research Center in the US, and the National University of Singapore.
Source: Duke-NUS
