50+ generate more natural antibodies than those below 50 years: Study
People who receive the Pfizer or AstraZeneca Covid-19 vaccine have antibody levels significantly higher than those infected with the SARS-CoV-2 virus, according to a study published in Scientific Reports journal on Monday. Interestingly, the team led by researchers at the University of Montreal in Canada also found that these antibodies were also effective against the Delta variant.
More than that, what surprised the researchers most was that antibodies produced by naturally infected individuals aged 50 and older provided a greater degree of protection than adults below 50 years of age.
In the study, 32 non-hospitalised Covid-19 positive Canadian adults were recruited 14 to 21 days after being diagnosed through PCR testing in 2020, before the Beta, Delta and Gamma variants emerged.
“Everyone who had been infected produced antibodies, but older people produced more than adults under 50 years of age,” said Jean-Francois Masson, a professor at the University of Montreal.
“In addition, antibodies were still present in their bloodstream 16 weeks after their diagnosis,” Masson said. Antibodies produced after an infection by the original viral strain also reacted to SARS-CoV-2 variants that emerged in subsequent waves, namely Beta, Delta and Gamma, with a reduction of 30 to 50 per cent in reactivity.
“But the result that surprised us the most was that antibodies produced by naturally infected individuals 50 and older provided a greater degree of protection than adults below 50,” said Joelle Pelletier, a professor at the University of Montreal.
“This was determined by measuring the antibodies’ capacity to inhibit the interaction of the Delta variant’s spike protein with the ACE-2 receptor in human cells, which is how we become infected,” he added.