top of page

How Long Does COVID Immunity Last?

The information on the coronavirus outbreak is continually evolving. The content within this activity serves as a historical reference to the information that was available at the time of this publication. We continue to add to the collection of activities on this subject as new information becomes available. It is the policy of Medscape Education to avoid the mention of brand names or specific manufacturers in accredited educational activities. However, manufacturer names related to COVID-19 vaccines may be provided in this activity to promote clarity. The use of manufacturer names should not be viewed as an endorsement by Medscape of any specific product or manufacturer.

Clinical Context

Both cellular and humoral immunity are important in the defense against viral infections, and a study by Breton and colleagues[1] evaluated the cellular immune response to SARS-CoV-2 among 41 adult patients with a previous positive reverse-transcriptase polymerase chain reaction test for the virus. The sample was 63.4% male and represented a wide range of ages. Most participants had mild COVID-19. Participants were followed for 6 months to assess the durability of the cellular immune response to SARS-CoV-2.

The proportion of cluster of differentiation (CD)4+ T cells decreased at 1.3 months after infection whereas the concentration of CD8+ T cells increased at this time. By 6.1 months after infection, levels of both CD4+ and CD8+ T cells had returned to physiologic levels. Central memory CD4+ and CD8+ T cells also decreased by month 6.

On in vitro testing with SARS-CoV-2 peptides, convalescent plasma from participants demonstrated a robust response of memory markers and inflammatory molecules. This response declined by only 22% to 32% by month 6.1 after infection. As a comparison, the inflammatory responses to cytomegalovirus peptides remained unchanged over the 6-month study period.

The authors concluded that a robust cellular immune response is likely for at least 6 months after infection with SARS-CoV-2, but what about the humoral response? Another study by Turner and colleagues examines this issue and is summarized under "Study Highlights."

Read more here :

1 view0 comments

Recent Posts

See All


bottom of page