Based on recent studies and expert guidance:
- Reinfections with COVID-19 can occur as soon as about 28 days after a previous infection, though it is more common to see reinfections after at least two months or longer. Immunity from a prior infection typically protects against reinfection for several months but wanes over time, especially with new variants emerging.
- Some studies have defined reinfections only if they occur at least two months after the first infection. However, newer variants like Omicron and its subvariants have increased the risk and shortened the timeframe for reinfections, sometimes within one to two months.
- The Centers for Disease Control and Prevention (CDC) notes reinfection can happen as early as several weeks after a prior infection, but this is rare. Protection against severe illness usually lasts longer than protection against reinfection itself.
- Factors influencing how soon reinfection can occur include waning immunity, the appearance of new variants with immune escape capabilities, vaccination status, and individual health conditions.
In summary, while it is uncommon, it is possible to catch COVID-19 again as soon as about 28 days after a previous infection, with reinfection risk increasing over time as immunity fades and the virus evolves. Most reinfections tend to be milder, but staying up to date with vaccines is important to reduce severe outcomes.
