Safety of COVID-19 vaccination in people with long COVID

To investigate the safety of COVID-19 vaccination in people who have long COVID, researchers in Bristol, England, conducted an observational study of 36 people who had been hospitalized for acute COVID-19. Overall, vaccination was safe and did not make symptoms of long COVID worse or degrade quality of life.

Study details

Researchers recruited participants who had symptoms of long COVID about eight months after they were hospitalized for acute COVID-19. Participants were vaccinated between January and February 2021.

The average profile of participants at the start of the study was as follows:

  • age – 54 years
  • 58% men, 42% women
  • major ethno-racial groups: 86% white; 14% people of colour
  • body mass index (BMI) – 32 kg/m2

The vaccine was distributed as follows:

  • 18 people received the Pfizer-BioNTech vaccine
  • 18 people received the Oxford-AstraZeneca vaccine


Participants had what researchers called “a high burden of persistent symptoms [of long COVID],” usually four symptoms per person. The most common symptoms were as follows:

  • fatigue – 75%
  • breathlessness – 61%
  • sleeping problems – 53%
  • brain fog – 40%

At the start of the study, analysis of quality of life and mental well-being assessments found that participants had lower ratings than what would have been obtained from healthy people.


One month after vaccination, participants were surveyed and researchers found that mental well-being and health-related quality of life were stable.

Overall, 72% of participants reported vaccination-related side effects. These were temporary (usually lasting a couple of days) and were as follows:

  • fever – 44%
  • muscle aches – 22%
  • headache – 19%

No major safety issues were reported.

Overall, the impact of vaccination on symptoms of long COVID was modest. One month after vaccination, participants reported the following:

  • 23% of symptoms had improved
  • 71% of symptoms stayed the same
  • 6% grew worse

For the future

People with long COVID need interventions to help them recover. There have been anecdotal reports that COVID-19 vaccines have improved the health of some people with long COVID. However, the design of the present study precludes drawing firm conclusions about the effectiveness of using these vaccines as a potential intervention for long COVID. For instance, this was not a randomized controlled clinical trial.

Still, the report from Bristol is a good step forward and demonstrates the safety of COVID-19 vaccines in a small group of people with long COVID.

—Sean R. Hosein


  1. Arnold DT, Milne A, Samms E, et al. Symptoms after COVID-19 vaccination in patients with persistent symptoms after acute infection: a case series. Annals of Internal Medicine. 2021; in press.
  2. Stamatatos L, Czartoski J, Wan YH, et al. mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection. Science. 2021 Jun 25;372(6549): 1413-1418. 
  3. Reynolds CJ, Pade C, Gibbons JM, et al. Prior SARS-CoV-2 infection rescues B and T cell responses to variants after first vaccine dose. Science. 2021 Jun 25; 372(6549):1418-1423.