Could vaccines beat back Omicron? South African study offers first clues

Highly mutated variant much better at evading existing mRNA vaccine than previous coronavirus strains, but boosters could help, study indicates

Findings of Durban-based researchers come after Swedish study found ‘highly variable’ reduction in antibody levels relative to original strain

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A mobile Covid-19 vaccine clinic gets the message across in Manhattan, New York. Photo: Reuters

Published: 4:58pm, 8 Dec 2021Updated: 8:53pm, 8 Dec 2021

South African researchers have provided the first tentative answers to the question of how well vaccines currently in use may protect against Omicron, the new and highly mutated coronavirus variant.

Their findings, made public on Tuesday ahead of peer review, indicated the variant was significantly better at evading virus-fighting antibodies produced by the Pfizer/BioNTech vaccine than previous strains. However, evasion was not complete and boosters could help increase protection, the findings suggested.

The results are the first set of what is expected to be a deluge of data on the subject in the coming days. Scientists have cautioned about the need for more research, real-world data and corroboration, with an early study from Sweden already showing less stark reductions in protection in previously infected people.

The Durban-based South African research team led by virologist Alex Sigal found people who had received two doses of the Pfizer/BioNTech mRNA shot experienced a fortyfold reduction in levels of neutralising antibodies against Omicron, compared to those against an earlier strain used to build the vaccine.

However, people who had been infected with Covid-19 before vaccination retained considerable immunity – a finding some scientists say suggests boosters could have a similar effect and shows the variant cannot completely escape antibodies.

The research “strongly suggests that the Sars-CoV-2 Omicron variant escapes antibody immunity induced by the Pfizer-BioNTech (Comirnaty) vaccine, but that considerable immunity is retained in people who were both vaccinated and previously infected”, said a statement from the Africa Health Research Institute, where Sigal and his co-authors are based.

Could vaccines beat back Omicron? South African study offers first clues

Highly mutated variant much better at evading existing mRNA vaccine than previous coronavirus strains, but boosters could help, study indicates Findings of Durban-based researchers come after Swedish study found ‘highly variable’ reduction in antibody levels relative to original strain

Highly mutated variant much better at evading existing mRNA vaccine than previous coronavirus strains, but boosters could help, study indicates

Findings of Durban-based researchers come after Swedish study found ‘highly variable’ reduction in antibody levels relative to original strain