Older people may generate more natural immunity from COVID-19 infection than younger adults, a new study suggests.
Researchers at the Université de Montréal, in Canada, found that antibody levels among people aged 50 and older were higher than in those aged 49 and younger.
The team also found that people who receive the Pfizer-BioNTech or AstraZeneca Covid vaccines are more protected from the virus than those relying on natural immunity alone.
The immunity from previous infection is still effective against different strains of the virus, though, including the highly contagious Delta variant.
Results of the study surprised researchers, and they cannot determine why older people seem to have stronger immune responses to infection.
Researchers found that people over the age of 50 were generating more natural immunity to COVID-19 after contracting the virus. Their immunity was effective against the native virus strain (black), the Beta variant (red), the Delta variant (blue) and the Gamma variant (gray)
'Everyone who had been infected produced antibodies, but older people produced more than adults under 50 years of age,' said Jean-François Masson, a chemistry professor at the university and co-lead researcher of the study, said in a statement.
'In addition, antibodies were still present in their bloodstream 16 weeks after their diagnosis.'
Researchers, who published their findings in Scientific Reports on Monday, gathered data from 32 Covid survivors whose illness did not require hospitalization.
Participants were split into groups based on their age, and then had samples collected to determine their antibody levels at four and 16 weeks after infection.
Each of the participants were infected with the virus at some point in 2020, and had contracted the native strain of the virus that originated in Wuhan, China.
They were found to have generated some natural immunity to the virus after infection, and researchers determined that the antibodies are effective
