The Impact of Vaccines on Long Covid

Research suggests that COVID-19 vaccination may serve a therapeutic effect, possibly reducing the risk of developing long COVID when administered to those currently infected.

Among the many mysteries of the COVID-19 pandemic, one of the most confounding to the medical community is that of “long COVID,” which refers to patients whose symptoms persist months after their COVID infection.

While most patients who contract COVID-19 improve within weeks of infection and don’t become severely ill, estimates show that about a quarter of patients experience long COVID, with symptoms ranging from fatigue and shortness of breath to onset of new chronic conditions, such as hair loss, for many months after becoming infected. Some people with long COVID may lose careers or undergo financial ruin due to the severity of their symptoms.

Long-COVID has the potential to alter lives and can derail the health and plans of those affected by it. For that reason, long-COVID can be considered a disability under the Americans with Disabilities Act (ADA) if it substantially limits one or more major life activities. That’s why it is crucial to both public health and welfare that the minimization of long COVID be considered a critical public health objective alongside reduction of the spread of COVID-19.

A study of vaccination and long COVID that we recently conducted offers some help in that regard. A quarter-million patients infected with COVID-19 were included in our analysis. We found found that vaccination prior to — or soon after — infection protects those who are infected with COVID-19 against the effects of long COVID.

Although vaccination soon after infection would run contrary to current CDC guidance, these findings suggest that earlier vaccination could lead to a decline in the number of patients suffering the effects of long COVID.

Before delving into the details of our study, it’s worth taking a deeper look at long COVID and exactly what the CDC advises for those seeking vaccination while experiencing COVID-19 symptoms.

A complicated, persistent problem


Among the most insidious aspects of long COVID is that it can strike even the asymptomatic.

According to the CDC , long COVID symptoms can surface in anyone who has contracted the disease, even if the person had only mild or no initial symptoms. Sufferers of long COVID report experiencing persistent symptoms ranging from fatigue and shortness of breath to brain fog, heart palpitations, pins-and-needles feelings, sleep problems, and changes in smell or taste.

The specificity of those symptoms belies the potentially far-reaching effects of long COVID, which has the potential to affect all of the body’s organ systems and may require prompt and sustained attention in more severe cases. Children can also experience long COVID, and the disease appears tod disproportionately affect women compared with men, according to the American Medical Association.

So far, it’s unclear why some patients who contract COVID continue to experience long COVID symptoms. Researchers are investigating this important question; studies to-date have been inconclusive.

A new look at vaccinations for symptomatic patients


CDC guidelines updated as recently as December 2021 instruct people experiencing COVID 19 symptoms to avoid being vaccinated until symptoms disappear. Specifically, the CDC recommends providers “defer vaccination of people with known current SARS-CoV-2 infection until the person has recovered from acute illness (if the person has symptoms) and until criteria have been met for them to discontinue isolation.”

However, our analysis of COVID patients (in collaboration with the COVID-19 Patient Recovery Alliance), found that unvaccinated patients who received their first COVID-19 vaccination within four weeks of infection were up to six times less likely to report multiple long COVID symptoms compared to those who remained unvaccinated.

We also discovered that those who received their first dose four-to-eight weeks after diagnosis were still three times less likely than those who remained unvaccinated to report multiple long COVID symptoms.

Our study suggests that COVID-19 vaccines may serve a therapeutic effect, potentially reducing the incidence of long COVID when administered to those currently infected, and that that protective effect is greater the earlier the vaccine is administered. If further studies on safety and efficacy of acute-phase COVID-19 vaccination bear out these results, significant public health benefits could be realized as fewer of the unvaccinated who become infected with COVID-19 experience long COVID.

While clinicians and researchers continue critical research into long COVID and COVID-19 more generally, it’s important to keep in mind patients continue to suffer each day from this debilitating and complex condition.

For those who are unvaccinated, this study adds yet another reason — protection against long COVID — to get vaccinated as soon as possible.

For those who find themselves infected, it offers hope that earlier vaccination, even while symptomatic, can help reduce the likelihood of developing long COVID.

Rich Parker, M.D., is chief medical officer at Arcadia, a data analytics platform for healthcare and life sciences. Parker was one of the principal researchers of the study titled, “Reduced Incidence of Long-COVID Symptoms Related to Administration of COVID-19 Vaccines Both Before COVID-19 Diagnosis and Up to 12 Weeks After, ” which is available on preprint sevice, medRxiv. He also contributed to a new white paper on “What Drives Long-COVID?”