Coronavirus antibodies might not last long, according to a new study from the Barcelona Institute for Global Health.

A total of 36% of unvaccinated COVID-19 patients had no detectable antibodies left one year after infection.

Researchers looked at over 1,000 people and found it was especially the case for adults over the age of 60 and smokers.

The study shows the longest-lasting protection comes from vaccination plus a prior infection.