A new study by Australian researchers has found how our immune system responds to COVID-19, revealing that those infected by early strains in 2020 produced sustained antibodies, but those antibodies are not effective against new variants of the virus.
The study, published in PLOS Medicine, has suggested that vaccination is more effective than the body’s natural immune response to the infection. The findings have also shown the need to invest in new vaccines in order to keep pace with emerging variants.
The researchers analyzed the serum of more than 230 individuals diagnosed with COVID-19 over 7 months. They found that the immunity level over time is dependent on the severity of the disease and the viral variant.
They also found that antibodies developed during the first wave had reduced effectiveness against six variants, ranging from those observed in the second wave in Australia through to three variants of concern that have driven the global pandemic in the UK, Brazil, and South Africa, according to Science Daily.
Co-senior author Prof. FabienneBrilot of the University of Sydney and Kids Research, Sydney Children’s Hospitals Network, and her team led the research using highly sensitive tools they developed to study the antibodies in detail.
She said, “We can learn a great deal from these people who were infected in the first wave in Australia as they were infected with the same variant that our current vaccines are based on.”
“While the approved vaccines are showing good responses, our study highlights the importance of continued vaccine development, especially taking into account the differences in variants,” added Prof. Brilot.
Another co-senior author Prof. Stuart Turville of the Kirby Institute said they wanted to investigate the level, breadth, and longevity of the immunity generated from COVID-19 infection. They also wanted to know whether mutation of the virus compromises immunity.
“What this work has shown us is that current observations about vaccines show they offer a much broader protection against COVID-19 and its variants than the body’s natural immune response following infection, which is usually only protective against the variant of the virus that the person was infected with.”
“We, therefore, should not rely on the body’s natural immune response to control this pandemic, but rather the broadly protective vaccines that are available,” he added.
The study found that COVID-19 antibody responses are sustained for up to seven months after infection and the immune response remained stable in some individuals, while it decreased in others.
The team also found that the Levels of virus-neutralizing antibodies were associated with the severity of COVID-19.
The study co-first author Fiona Tea said, “What makes this study stand out is the level and depth of analysis to neutralizing antibody levels in people recovering from COVID infection over time, including comparison of infection recovering from different viral variants.”
The article was published in Science Daily.
