Australian researchers have found that vaccine-induced T cells can provide more than a year of immunity to COVID-19.
A study from the Doherty Institute, published Wednesday in the journal Nature Immunology, showed that the body’s T cells provide long-lasting memory against the virus after vaccination or infection with COVID-19.
T cells play a crucial role in supporting the development of the body’s B cell response, which helps produce the antibodies that recognize COVID-19 and stop the infection.
Using a new technology called tetramers, researchers tracked T cell responses in people who had recovered from COVID-19 for 15 months and found that sustained levels of these cells were able to recognize the SARS-CoV-2 spike protein.
“Even though parts of the immune response are waning, we can now see that virus-recognizing T cells are quite stable over time,” said paper author Jennifer Juno.
“After more than a year, they were still about 10 times higher than someone who had never been exposed to the spike protein through infection or vaccination.
“The vaccination increased the levels of these T cells to be up to 30 times higher than they were before.”
The researchers also found that a third dose of the COVID-19 vaccine did an “incredible job” of reactivating T cells and bringing their levels back up again, she said.
The Doherty Institute is currently studying how T cells react when vaccinated people catch COVID-19, to understand if they are reactivated in the same way.
It comes as international travelers could soon see their pre-departure testing requirements scrapped after the Prime Minister signaled further easing of COVID-19 restrictions.
Travelers must currently show a negative test result to board a flight to Australia, even if they are fully vaccinated.
Prime Minister Scott Morrison has said the abolition of pre-departure testing is an important step for Australia.
Health Minister Greg Hunt will make an announcement soon.
“While we are never satisfied with the challenges COVID can present and new variants, we are watching all of these closely as we continue to look through this windshield,” Mr Morrison told reporters in Cairns. Tuesday.
“Hopefully we can continue to see COVID in the rear view mirror.”
But a spokesperson for Mr Hunt said he was continuing to receive health advice before making further changes to Australia’s biosecurity measures.
The current biosecurity declaration is due to expire on April 17, aligning with the return of international cruise ships to Australian waters for the first time since March 2020.
LATEST 24/7 COVID-19 DATA FROM ACROSS AUSTRALIA:
NSW: 24,115 cases, five deaths, 1,162 in hospital
Vic: 10,471 cases, 11 deaths, 243 hospitalized
Heap: 1,825 cases, no deaths, 32 in hospital
Qld: 10,476 cases, seven deaths, 252 in hospital
ACT: 1314 cases, no deaths, 42 hospitalized
WA: 8429 cases, one death, 194 hospitalized
SA: 4,594 cases, two deaths, 161 hospitalized
NT: 328 cases, no deaths, 18 in hospital
Australian Associated Press