Coronavirus immunity lasts up to eight months providing hope for long-term protection by vaccines

Immunity against coronavirus can last up to eight months after infection, new Australian research by Monash University has revealed, providing hope for long-term protection by vaccines.

The study, by Monash University's Department of Immunology and Pathology and Alfred Research Alliance, uncovered a memory B cell which "remembers" the virus and triggers the production of protective antibodies if re-exposed.

LIVE UPDATES: Border between NSW and Victoria reopens

Published in MedRxiv, the study tested 25 COVID-19 patients and took blood samples post infection from day four until day 242.

Researchers found that antibodies started to drop off after 20 days post infection, however, virus-specific memory B cells were present up to eight months after infection.

"These results are important because they show, definitively, that patients infected with the COVID-19 virus do in fact retain immunity against the virus and the disease," Associate Professor at Monash University, Menno van Zelm, who led the study, said.

The research comes just days after vaccine candidate Pfizer announced its vaccine appears 95 per cent effective at preventing mild to severe COVID-19 disease, while its competitor Moderna said its vaccine appears to be 94.5 per cent effective.

The study is the strongest evidence that a COVID-19 vaccine would work for long periods, researchers said, with previous studies finding antibodies diminish in the first few months – meaning people may lose immunity to the virus quickly.

"This has been a black cloud hanging over the potential protection that could be provided by any COVID-19 vaccine and gives real hope that, once a vaccine or vaccines are developed, they will provide long-term protection," Mr van Zelm said.