For the aims of the proposed project, a scoping review is preferable to a systematic review as the former is useful when examining emerging evidence when there is a lack of clarity as to what more specific questions may be valuably addressed in a systematic review (26), and in which we have documented expertise (27–30).
Inclusion and exclusion criteria
We will not restrict articles by type of COVID-19 vaccine or by country of study. Gray literature searches will be restricted to those published languages spoken by the research team (Table 1).
Concept
In keeping with the Arksey and O’Malley framework for methodological reviews (31), searches and screening will be independently but concurrently performed by trained staff (initials blinded for review). Articles will be included based on consensus. In the event of conflicts, the study lead (initials blinded for review) will guide a decision.
Information sources
Four scientific databases (CINAHL, PsycINFO, Medline, Embase) will be searched, but no restrictions to patient age or language of publication. Due to the nature of the topic, the literature will be exclusively from 2020 onward.
Gray literature sites will include, but are not limited to websites of the Canadian Society of Allergy and Clinical Immunology, American Academy of Allergy, Asthma and Immunology, European Academy of Allergy and Clinical Immunology, and World Health Organization.
Initial search strategy
The original search will be guided by (initials blinded for review), approved by the study lead (blinded for review), then peer-reviewed by a librarian colleague, per Peer Review of Electronic Search Strategies guidelines (32). The search strategy is presented in Table 2.
Screening
After the initial search, all citations will be uploaded into Rayyan (33). Trained student research assistants will de-duplicate the search. Thereafter, they will independently perform title and abstract screening, noting which studies are to be excluded or included from the full text screening. This process will be blinded, such that each screener does not have access to whether the other screener has decided to include or exclude an article based on the title/abstract.
After the title and abstract screening is complete, full texts will be uploaded to Rayyan (33). Full text screening will follow the same process as for the title and abstract screening described above. Decisions whether to exclude (and the reason for exclusion) or include the full text in the review will be based on the inclusion criteria. Once screeners have independently screened the full texts, the results will be unblinded. Screeners will meet to discuss any conflicts, and in they event they cannot agree whether an article should be included, they will defer to the study lead or her designate.
For articles that are published in languages other than English, the decision to exclude or include an article will be at the discretion of the team member(s) who speak/read that language. Screeners will direct the article(s) to team members who read the particular language.
For all included articles, data will be extracted into tables. The tables, at a minimum, will include the study’s title, authors, year of publication, country of the participants, aims, sample size, study methodology, outcome measures, and key findings. At the point of extraction, the students will be asked to extract all information that may be relevant to the review. A flow chart of the search process will also be included in the initial scoping review, per the structure provided by the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (34).
Bi-monthly update
A bi-monthly search alert based on the search strategy will be generated by health sciences librarian (initials blinded for review). The students assigned to this project will be tasked with screening these articles and assessing if they should be excluded or included. Conflicts between the students regarding the inclusion of particular articles will be solved through discussion. If the students cannot agree, the study lead or her designate will be asked to make the final decision.
Patient engagement
Patients have been involved at all stages of this study, a process that we commit to continuing.
Ethics
As this is a scoping review of existing literature, no ethical approval is required. However, the overarching study has been approved by the University of Manitoba Health Research Ethics Board.
Knowledge translation
Following preparation of the manuscript, we will post it on a pre-print server, and submit for publication. Per conditions of funding of COVID grants, this – and all resulting publications from this project – must be open access. These updates will follow the same process as described above. Bi-monthly updates will be posted on a pre-print server. Depending on the volume of literature, these updates will be synthesized and submitted for peer-review at 6 and/or 12 months.
Plain language summaries, in the form of infographics, will be posted on the study lead’s website (35) and shared widely on social media.