A small unreviewed study in Austria suggests those who have been vaccinated and exposed to the SARS-CoV-2 virus may develop a hybrid super immunity.
The Austrian study, which included around 100 participants, suggests that vaccination combined with recovery from infection, regardless of the order, may produce a hybrid immunity that can neutralise all forms of SARS-CoV-2.
Austrian researchers led by Annika Rössler from the Institute of Virology at the University of Innsbruck tested antibody titers against Omicron from both recovered people and people who were vaccinated with Astrazeneca, Biontech / Pfizer and Moderna and found that vaccine-induced antibodies neutralise the Omicron variant to a much lesser extent than other variants.
However, those who had a SARS-CoV-2 infection and were then vaccinated once or twice with the Biontech / Pfizer vaccine or vice versa, had antibodies that were able to neutralise Omicron. And those vaccinated with the Biontech / Pfizer vaccine or a mixture of Astrazeneca followed with Biontech were able to neutralise Omicron to some extent.
A study done in September 2021 at Rockefeller University in New York produced similar findings. Researchers there changed the spike protein of the coronavirus in the laboratory, resulting in a variant with 20 changes, similar to Omicron, that made it resistant to the neutralising antibodies of most of those who were vaccinated or recovered. Researchers found that those who were both vaccinated and had recovered from an infection were much better equipped to fight the altered virus.
In addition, there is also evidence from Biontech that vaccine-induced immunity can still outsmart the Omicron variant without antibodies because the virus cannot bypass the T-cell immune response.