- Study participants were divided into four age groups.
- The study looked at the development of natural antibodies in each age group.
- It also showed that vaccination doubled Covid-19 antibodies.
A new study found older people who recovered from Covid-19 had higher antibody levels than younger people.
The study in Scientific Reports investigated whether natural infection or vaccination led to more protective antibodies generated by the various Covid-19 variants.
The study enrolled 32 non-hospitalised Covid-19 positive individuals 14 to 21 days after being diagnosed through PCR testing. The group was divided into four age groups: 18 to 49; 50 to 59; 60 to 69; and 70+. Each age group consisted of eight people.
The researchers collected blood samples from the participants four and 16 weeks post-diagnosis to measure antibodies.
Older people have more antibodies
The study found that age correlated with the concentration of post-infection antibodies.
People aged 70+ years generally had higher than average antibody responses than those younger than 49 years, who saw below average antibody responses, and those aged 50–69 years, who had an intermediate response.
"Everyone who had been infected produced antibodies, but older people produced more than adults under 50 years of age.
"In addition, antibodies were still present in their bloodstream 16 weeks after their diagnosis," said co-author Prof Jean-François Masson in a press statement.
The study also found people who had mild Covid-19 and were vaccinated had double the antibody levels compared to unvaccinated, infected people.
"But what's even more interesting is that we have samples from an individual younger than 49 whose infection didn't produce antibodies inhibiting spike-ACE-2 interaction, unlike vaccination.
"This suggests that vaccination increases protection against the Delta variant among people previously infected by the native strain," Masson said.