Effect of COVID‑19 booster vaccination on the prevalence of post‑COVID conditions and on the severity of post‑COVID symptoms

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SBU Enquiry Service

Consists of structured literature searches to highlight studies that can address questions received by the SBU Enquiry Service from Swedish healthcare or social service providers. We assess the risk of bias in systematic reviews and when needed also quality and transferability of results in health economic studies. Relevant references are compiled by an SBU staff member, in consultation with an external expert when needed.

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Published: Report no: ut202602 Registration no: SBU 2025/1142

Question

Which systematic reviews examine the effects of COVID 19 booster vaccination on the prevalence of post COVID conditions and the severity of post COVID symptoms among adults who have received primary vaccination?

PICO

  • Population: Adults who have received primary vaccination against SARS CoV 2
  • Intervention: Booster vaccination against SARS CoV 2 (particularly Omicron adapted vaccines)
  • Comparison: No booster vaccination
  • Outcome: Prevalence and severity of post COVID conditions

Method

A systematic literature search was performed using the following databases: Medline (Ovia), Scopus.
Two authors independently assessed the abstracts of all identified studies.
Risk of bias in relevant systematic reviews was assessed using an assessment tool based on AMSTAR.

Identified literature

One relevant systematic reviews with low to moderate risk of bias were identified [1]. The results and conclusions are presented in Table 1. In four relevant systematic reviews, the risk of bias was considered to be high, therefore the results and conclusions are not reported [2-5].

Table 1 Systematic reviews with low/moderate risk of bias.
CI = confidence interval; n = number of studies; N = number of participants; OR = odds ratio
When two numbers are presented (e.g., N = 16 831/9912), the first represents the number of participants in the intervention.
Included studies Population, Intervention, Control Outcome and Results
Green et al, 2025 [1]
A systematic review and meta-analysis of the impact of vaccination on prevention of long COVID
Included studies:
Total studies in review: 31 

Relevant studies contributing to the two booster analyses:
5 observational
  • prospective (3)
  • retrospective (2)

Setting: USA (3), Germany (1), UK (1)		 Population:
Participants with laboratory‑confirmed SARS‑CoV‑2 infection during the omicron period, including all age groups. 

Intervention:
COVID-19 vaccination prior to infection, using EU-authorized vaccines at the time of the study. 

Control:
Participants who were unvaccinated or had received fewer doses than the intervention group.		 Risk of postcovid:Booster vaccination vs primary vaccination:
OR=0.77
(95% CI, 0.65 to 0.92)
p=0.004
n=3 studies (adults)
N (reported) = 16 831/9912
Interpretation: Booster vaccination was associated with a significantly lower risk of long COVID compared to primary vaccination alone. 

Booster vaccination vs unvaccinated:
OR=0.74
(95% CI, 0.63 to 0.86)
p=0.0001
n=4 studies (adults)
N (reported) = 158 988/105 685
Interpretation: Booster vaccination was associated with a significantly lower risk of long COVID compared to no vaccination.
Authors' conclusion:“Booster vaccination prior to omicron infection was associated with a significantly lower risk of developing long COVID compared to both unvaccinated individuals and those who had received only the primary vaccination series. The pooled analysis showed that booster doses reduced the risk by approximately 26% compared to unvaccinated individuals and by 23% compared to primary vaccination alone. These findings indicate that booster vaccination provides additional protection beyond the primary series. However, the certainty of evidence remains very low due to number of studies, observational study designs and heterogeneity, and further high-quality research is needed to confirm these results.”

References

  1. Green R, Marjenberg Z, Lip GYH, Banerjee A, Wisnivesky J, Delaney BC, et al. A systematic review and meta-analysis of the impact of vaccination on prevention of long COVID. Nat Commun. 2025;16(1):10326. Available from: https://doi.org/10.1038/s41467-025-65302-0
  2. Patel V, Korsun M, Cervia J. Protective effects of booster dose of SARS-COV-2 vaccination against post-acute COVID-19 syndrome: A systematic review. J Investig Med. 2025;73(8):606-13. Available from: https://doi.org/10.1177/10815589251346963
  3. Peine C, Stoliaroff-Pepin A, Reinacher U, Heldt K, Sarganas G, Piechotta V, et al. Effectiveness of COVID-19 vaccines against post-COVID-19 condition/long COVID: systematic review and meta-analysis. Clin Microbiol Infect. 2025;31(12):1961-71. Available from: https://doi.org/10.1016/j.cmi.2025.07.026
  4. Rudolph AE, Al Akoury N, Bogdanenko N, Markus K, Whittle I, Wright O, et al. Factors affecting the impact of COVID-19 vaccination on post COVID-19 conditions among adults: A systematic literature review. Hum Vaccin Immunother. 2025;21(1):2474772. Available from: https://doi.org/10.1080/21645515.2025.2474772
  5. Sterian M, Naganathan T, Corrin T, Waddell L. Evidence on the associations and safety of COVID-19 vaccination and post COVID-19 condition: an updated living systematic review. Epidemiol Infect. 2025;153:e62. Available from: https://doi.org/10.1017/S0950268825000378

Search strategies

Medline via OvidSP 17 October 2025

Title: Vaccination / Postcovid
/ = Term from the MeSH controlled vocabulary; .sh = Term from the MeSH controlled vocabulary; exp = Term from MeSH including terms found below this term in the MeSH hierarchy; .ti,ab = Title or abstract; .tw = Title or abstract; .kf = Keywords; .kw = Keywords, exact; .bt = Book title. NLM Bookshelf; .pt = Publication type; .ja = Journal abbreviation; .af = All fields; adjn = Adjacent. Proximity operator retrieving adjacent words, adj3 retrieves records with search terms within two terms from each other; * or $ = Truncation; “ “ = Citation Marks; searches for an exact phrase
Search terms Items found
Population: Postcovid
1. COVID-19/rh OR Coronavirus Infections/rh 562
2. ((covid* or coronavirus* or corona virus* or sars cov 2 or 2019 ncov) adj3 (after care or aftercare or chronic* or continuing or convalesc* or enduring or late or lingering or long* or non specific or nonspecific or permanent or persist* or post* or prolong* or rehab* or recover* or recurr* or relaps* or remaining or residing or residual or sequela* or sequelae* or telerehab*)).ti,kf. 21 225
3. ((covid* or coronavirus* or corona virus* or sars cov 2 or 2019 ncov) adj5 (after care or aftercare or chronic* or continuing or convalesc* or enduring or late or lingering or long* or longterm* or non specific or nonspecific or permanent or persist* or post* or prolong* or rehab* or recover* or recurr* or relaps* or remaining or residing or residua11386l or sequela* or sequelae* or telerehab*) adj5 (anxiet* or arrhythmia* or arrythmia* or asthma* or brain or breath* or cardiac* or cognit* or depress* or dizz* or dyspnea* or dysrhythmia* or fatigue or fever* or gustat* or heart* or insomnia or kidney* or lung* or nausea or neuro* or olfact* or pain or palpitation* or postural orthostatic tachycardia syndrome or pots or pneumoni* or pulmonary or respirat* or sleep* or smell* or spinning or symptom* or tast* or vertigo*)).ab. 11 386
4. Post-Acute COVID-19 Syndrome/ OR postcovid*.ti,ab,kf. 4569
5. COVID-19/ OR Coronavirus Infections/ OR (covid* or coronavirus* or corona virus* or sars cov 2 or 2019 ncov).ti,ab,kf. 504 916
6. (persist* adj5 symptom*).ti,ab,kf OR (long haul* or post acute or post viral or post virus or sequela* or sequelae*).ti,ab,kf. 127 401
7. (long covid* or post covid*).ab. 14 927
8. 1 OR 2 OR 3 OR 4 OR (5 AND 6) OR 7 31 785
Intervention: Vaccination
9. COVID-19 vaccines/ or Vaccination/ or Immunization/ or Vaccine efficacy/Vaccin*.ti,ab. or inoculat*.ti,ab. or immuni?ation.ti,ab. or (one dose* or two dose* or first dose* or second dose*).ti,ab. or (immunostimulation or 'immunologic stimulation').ti,ab. or unvaccin*.ti,ab. or pfizer.ti,ab. or astrazeneca.ti,ab. or mrna.ti,ab. or janssen.ti,ab. or 'johnson & johnson'.ti,ab. or Novavax.ti,ab. or Covaxin.ti,ab. or sinopharm.ti,ab. 1 324 737
Study types: systematic reviews and meta-analysis
10. (Systematic Review/ or Meta-Analysis/ or Cochrane Database Syst Rev.ja. or ((systematic adj4 review) or "meta analys*" or metaanalys*).ti,bt,ab. or (realist adj4 review).ti,bt,ab. or (integrative adj4 review).ti,bt,ab. or (mixed method* adj4 review).ti,bt,ab. or (umbrella adj4 review).ti,bt,ab.) not (editorial/ or letter/ or case reports/) 573 917
Combined sets:
11. 8 AND 9 AND 10 192
Final result
12.   192

Scopus via scopus.com 17 October 2025

Title: Vaccination/Postcovid
TITLE-ABS-KEY = Title, abstract or keywords (including indexed keywords and author keywords); ALL = All fields; W/n = Within. Proximity operator retrieving terms within n words from each other; PRE/n = Precedes by. Proximity operator, the first term in the search must precede the second by n words; LIMIT-TO (X) = Includes only results of specified type, e.g., publication type or time range; DOCTYPE = Publication type; “re” = review; “le” = letter; “ed” = editorial; “ch” = book chapter; “cp” = conference proceedings; * = Truncation; “ “ = Citation Marks; searches for an exact phrase
Search terms Items found
Population: Postcovid
1. ( TITLE-ABS ( "COVID-19" OR covid* OR coronavirus* OR "corona virus*" OR "sars cov 2" OR "2019 ncov" ) W/3 TITLE-ABS ("after care" OR aftercare OR chronic* OR continuing OR convalesc* OR enduring OR late OR lingering OR long* OR "nonspecific" OR non specific OR permanent OR persist* OR post* OR prolong* OR rehab* OR recover* OR recur* OR relaps* OR remaining OR residing OR residual OR sequela* OR sequelae* OR telerehab* ) OR TITLE-ABS ( postcovid* OR "long covid*" OR "post covid*" ) ) 54 036
Intervention: Vaccination
2. ( TITLE-ABS ( vaccin* OR inoculat* OR immuni?ation OR unvaccin* OR dose* OR pfizer OR astrazeneca OR mrna OR janssen OR "johnson & johnson" OR novavax OR covaxin OR sinopharm ) ) 3 563 521
Study types: systematic reviews and meta-analysis
3. TITLE-ABS-KEY ( ( (systematic OR realist OR integrative OR “mixed method*” or umbrella) W/3 review ) OR "meta analy*" OR metaanaly* ) AND (EXCLUDE (DOCTYPE, “le”) OR EXCLUDE (DOCTYPE, “ed”) OR EXCLUDE (DOCTYPE, “ch”) OR EXCLUDE (DOCTYPE, “cp”)) 863 617
Combined sets:
4. 1 AND 2 AND 3 387
Final result
5.   387
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