After infection with SARS-CoV-2, most people develop detectable serum antibodies but the antibody response may be variable. There is a protective immune response after infection or vaccination but this can be variable as well. The short-term risk of re-infection (within the first several months after initial infection) is low.
COVID-19 prevention can include infection control in the health care setting, personal preventive measures, wearing masks in the community, and social/physical distancing.
Post-exposure management includes staying alert for symptoms and exercising the prevention measures. For unvaccinated individuals, it is recommended that daily monitoring of symptoms and the preferred quarantine period is 14 days. For vaccinated individuals, the current guidelines for fully vaccinated individuals are exempt from the self-quarantine but should get tested 3 to 5 days after the exposure and wear a mask for 14 days or until the test is negative. For individuals with a recent history of infection (within three months) prior to the exposure are exempt from these self-quarantine and testing recommendations.
In the United States, the FDA (Food and Drug Administration) has issued an emergency use authorization (EUA) to uses a monoclonal antibody drug to prevent SARS-CoV-2 infection in select individuals over 12 years of age who have had close contact with an individual with an infection or who are at high risk of exposure to individuals with infection. But, the criteria for use must meet the emergency use authorization criteria. This criteria list is very detailed and those who are expected to have a inadequate immune response to the COVID-19 vaccination so it is recommended to discuss this with your healthcare provider. This monoclonal antibody drug is being studied in a clinical scientific trial.