We received a question about whether the immune systems of people with Down syndrome produce antibodies in response to COVID-19 vaccines. I have shared the response I sent below.
The immune system's response to any vaccine is key to preventing infections. However, some people with Down syndrome may not produce as high an antibody response to some immunizations as people without Down syndrome. The Trisomy 21 Research Society statement on COVID-19 vaccines includes links to some articles about a difference in antibody production after vaccination in people with Down syndrome.
Whether this is true for COVID-19 vaccines for people with Down syndrome has not yet been determined. We are aware that it is being studied. For example, a study is being done in the Netherlands on the efficacy of COVID-19 vaccines in people with Down syndrome.
Even if the antibody response is lower, some benefit is still expected. It is usually not that there is no benefit with a lower antibody response, just perhaps not as much protection. For example, in the population over age 65 (without Down syndrome), COVID-19 vaccines significantly reduce the risk for COVID-19-associated hospitalization. This is despite the fact that, like people with Down syndrome, some older individuals have impaired immunity that puts them at greater risk for infections and can reduce their response to vaccines. Although there is much to be studied regarding COVID-19 vaccine in populations with a potentially reduced response to vaccines, what we know so far is that there is benefit in preventing serious disease in at least some people (older individuals) who likely have reduced immune function.
At this point, we know that many people with Down syndrome are disproportionately affected by COVID-19, have greater risk of being hospitalized, and have a greater risk of dying from the infection. While more study is needed, even if the immune response is lower, it is likely that some benefit is obtained from the vaccine.