Vaccination and infection both provide protective immunity to COVID-19, particularly against severe disease. But gaining immunity through infection is far riskier than vaccination. Posts citing a new Lancet study omit that important context and also misleadingly claim the study shows immunity after infection is superior to vaccination immunity. A co-author of the study told us there was “insufficient data to definitively state” immunity from infection is superior.

How effective are the vaccines?

COVID-19 vaccination and infection each provide some temporary protection against future infection and stronger, longer-lasting protection against severe illness.

A recent Lancet study combined data from multiple past papers to estimate the degree and length of protection after getting COVID-19. The researchers, from the University of Washington’s Institute for Health Metrics and Evaluation, found that infection reduced the risk of reinfection, but that this protection diminished more quickly once omicron arrived in late 2021. (Before the emergence of omicron and its subvariants, there was the original virus followed by variants including alpha, beta and delta.) Protection against severe disease was high for all variants studied.

Drawing on their own data from a study that is not yet published, they also made comparisons to the immunity offered by vaccines. “Although protection from re-infection from all variants wanes over time, our analysis of the available data suggests that the level of protection afforded by previous infection is at least as high, if not higher than that provided by two-dose vaccination using high-quality mRNA vaccines (Moderna and Pfizer-BioNTech),” they wrote.