It is important to ask this question for all treatments in medicine. Unfortunately, long-term effects of many treatments are unknown, either because they are new and/or because we haven’t yet studied them. Thus far, we have data looking at short-term and intermediate effects related to COVID-19 vaccine administration and vaccine efficacy (see FAQ questions about vaccine efficacy and about allergic reactions). Over time, more data will be collected to understand long-term effects (both positive and negative) of the vaccine.
Health care systems and public health experts are recommending this vaccine because based on current evidence, they believe the risks of COVID-19 disease outweigh the risks of the COVID-19 vaccine. This recommendation is based on the best evidence available today, understanding that recommendations may change over time as we learn more about COVID-19 and/or its treatments.
Just as it is important to think about the long-term effects of the vaccine, it is also important to consider long-term effects of COVID-19 itself. While true long-term data is lacking, we are starting to learn about COVID-19 “long-haulers,” those who experience issues months beyond their initial recovery. Chronic symptoms may include fatigue, shortness of breath, cough, joint pain, and chest pain. There is concern that lung scarring from the virus may lead to more chronic problems. Imaging tests taken months after recovery have shown damage to the heart muscle, even in people who experienced only mild COVID-19 symptoms. This may increase the risk of heart failure or other heart complications in the future. Even in young people, COVID-19 can cause strokes, seizures and Guillain-Barre syndrome.
As with the vaccine, researchers will continue following individuals who have had COVID-19 to better understand the long-term effects of the disease.
Does the vaccine help with COVID-19 long-haulers?
The short answer: We don’t know, rigorous study of this is needed.
The long and more hopeful answer: Interestingly, there are recent anecdotal reports where COVID long haulers have experienced improvement in symptoms after receiving the vaccine. In the absence of large studies, researchers are collating information from patient stories, informal surveys and clinicians’ experiences. For example, about 40% of the 577 long COVID patients contacted by the group Survivor Corps say they felt better after getting vaccinated. A small UK study, not yet peer-reviewed, found about 23% of long COVID patients had an “increase in symptom resolution” post-vaccination, compared to about 15% of those who were unvaccinated. Yet, these reports are far from conclusive and there have also been clinicians in post-COVID clinics that have not seen this phenomenon. Formal studies are needed to determine if and how vaccination affects persistent COVID symptoms.