Table 2

Characteristics of included studies when vaccines were given after infection or after a diagnosis of long covid

Study, year, countryStudy type and timeframePatient or data sourceIntervention populationInterventionComparatorOutcomes of interest and length of follow-up
Ayoubkhani 2022, UK30Interrupted time series, 3 February-5 September 2021Covid-19 infection survey participantsn=28 356 patients with long covid, who had received at least one vaccine after diagnosisAstraZeneca, Pfizer, or ModernaSelf-controlled (symptoms before vaccine)Long covid of any severity after first and second dose ≥3 months. 10 most common symptoms
Simon 2021,
USA, preprint31		Retrospectively assembled cohort, February 2020-May 2021Arcadia data research dataset with >150 million patient recordsn=17 796 patients with a diagnosis of covid-19, by PCR or ICD-10 code U07.1 at any time or B97.29 before May 2020, and who were vaccinated within 12 weeks after a diagnosis of covid-19One dose of Pfizer, Moderna, or Janssenn=220 460 patients who were not vaccinated before covid-19 and 12 weeks afterOdds of having long covid at 3 months
Tran 2021,
France, preprint32		Prospective cohort, December 2020-September 20218ComPaRe (cohort of patients with chronic diseases)n=455 adults with a confirmed or suspected SARS-CoV-2 infection and at least one symptom attributable to long covid reported at baseline and persisting for >3 weeksAstraZeneca, Pfizer, Moderna, or Janssenn=455 1:1 propensity matched controls from the same cohort who were not vaccinatedRemission of all long covid symptoms by
four months
Wisnivesky 2022, USA33Prospective cohort, 20 July 2020-August 2021Patients with covid-19 enrolled in prospective registry established at Mount Sinai Health Systemn=324 adult patients with a history of laboratory confirmed covid-19, with one or more symptoms of long covid, treated at Mount Sinai and who were fully vaccinatedPfizer, Moderna, or Janssenn=129 patients from the same cohort who were not vaccinatedFatigue at six months
Wynberg 2022,
Netherlands34		Prospective cohort, 11 May 2020-1 November 2021RECoVERED study participantsn=36 patients with long covid, aged 16-85 years, with laboratory confirmed covid-19, Amsterdam residents, with >3 months of follow-upAstraZeneca, Pfizer, Moderna, or Janssenn=32 participants who were not vaccinated matched 1:1 on age, sex, obesity status, and time since illness onset to participants who were vaccinatedRecovery from long covid symptoms at ≥3 months since onset of illness

  • PCR=polymerase chain reaction; ICD-10=international classification of diseases, 10th version.