Need to Know: Long COVID & Vaccination

Following COVID-19, some people will experience long COVID, or persistent symptoms lasting for weeks or even months after initial infection. Long COVID, also known as post-acute sequelae of SARS-CoV-2 (PASC), can affect different parts of the body, such as the brain, heart and lungs—and it can affect people differently.

Common long COVID symptoms include, but are not limited to:

  • Tiredness, fatigue
  • Fever
  • Respiratory or heart symptoms, such as difficulty breathing, a cough and chest pain
  • Neurological symptoms, such as difficulty thinking or concentrating (brain fog), headache, sleep problems and lightheadedness
  • Loss of taste and/or smell
  • Digestive issues
  • Long COVID conditions

Long COVID can happen to anyone who has had COVID-19, even after mild or asymptomatic illness. An estimated 54% of COVID-19 survivors experience at least one symptom of long COVID six months after infection.

Severe disease and hospitalization due to COVID-19 may increase the risk of long COVID:

  • A new study estimated that 68% of hospitalized patients from COVID-19 still had symptoms six months later, and 55% had symptoms two years later.
  • Another study showed that only one in four survivors felt fully recovered a year after being released from the hospital.
  • Click here for more data on long COVID.

So far research suggests that being vaccinated against COVID-19 can reduce the risk and duration of long COVID, especially if you are vaccinated before getting COVID-19.

One study showed that the risk of developing long COVID decreased by 41-50% among fully vaccinated people. Additionally, individuals who got a COVID vaccine after having COVID reported a shorter duration of long COVID symptoms compared to those who remained unvaccinated. Individuals with even one dose of an mRNA COVID vaccine were less likely to develop long COVID.

Scientists are working hard to learn more about long COVID. For one, the definition of long COVID is still being worked out, and so are the symptoms. Not all researchers define long COVID the same way, measure it by the same symptoms, or track patients for the same length of time. This may contribute to varying estimates of long COVID prevalence. More studies with diverse patient populations are also needed to understand long COVID risk factors and how long COVID affects people differently.

Additionally, much of the published data is from early in the pandemic. It is too early to tell what long COVID looks like since the Omicron variant took hold, and researchers are still evaluating the effect of boosters on long COVID.

  • Long COVID is a common condition, with over half of COVID-19 survivors experiencing at least one long COVID symptom six months after infection.
  • Vaccines do offer some protection against SARS-CoV-2 infection. By avoiding infection, we can prevent long COVID.
  • Anyone who has had COVID-19 is at risk for long COVID, but hospitalization due to COVID-19 may increase this risk.
  • Vaccines are effective at preventing severe outcomes from COVID-19, including hospitalization and death. By preventing severe disease, vaccines should help reduce the risk and duration of long COVID.

The research on long COVID is ongoing. Want to learn more? Check out the following resources: