Unsung Heroes

Once overshadowed by antibodies, T cells begin to take center stage in the fight against COVID-19

Illustration of a T cell
Image: Design Cells/iStock/Getty Images Plus

This article is part of Harvard Medical School’s continuing coverage of COVID-19.

Since the start of the COVID-19 pandemic, antibodies have dominated the attention of both physician-scientists and the public. They have been the object of intense research across scientific labs. They formed the basis of SARS-CoV-2 vaccines and antibody-based therapies, acquiring household-name status in the process.

This fame is well-deserved.

Get more HMS news here

Churned out by the immune system when it encounters a pathogen, or made in response to vaccines that mimic one, these tiny proteins glom onto SARS-CoV-2 to gum up its cell-entry machinery, preventing the virus from invading cells and turning them into virus-making factories that cause widespread infection. Vaccines designed to elicit antibodies against SARS-CoV-2 are a feat of modern science and remain the most critical tool in taming the contagion.

If antibodies are the rampart around the castle, then T cells are the elite guards inside it that disable intruders should they manage to sneak in.