Back

Asymptomatic SARS-CoV-2 infections tend to occur less frequently in developed nations

Chowdhury, S.; Tiwari, A.; James, A.; Chatterjee, B.; Dixit, N. M.

2023-12-14 public and global health
10.1101/2023.12.14.23299954 medRxiv
Show abstract

Unlike severe infections, asymptomatic infections occur independently of healthcare access and reflect the natural immunity to SARS-CoV-2. What determines their prevalence,{psi} , and its variation across nations is unknown. We conducted a systematic review of serosurveys performed on samples representative of national populations before vaccination and the emergence of variants. The studies that met our selection criteria together sampled 4,58,489 individuals and yielded estimates of{psi} in 33 nations. Using random-effects modeling, we found the pooled global{psi} to be 45.3% (95% CI: 33.6%-57.5%).{psi} varied widely across nations (range: 6%-96%; I2=99.7%), highlighting the enormous underlying variation in the natural immunity to SARS-CoV-2. Performing meta-regression with national-level metrics, we found that the human development index (HDI) was negatively correlated with{psi} (p=10-13; R2=65.5%). More developed nations thus experienced less frequent asymptomatic infections on average. These findings have implications for unraveling the origins of asymptomatic infections and for future pandemic preparedness.

Matching journals

The top 6 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.