Badea, A; Miller, L; Young, C. What is the evidence on volume of surgery with hip and knee replacements and quality of care? 2022 Jun 17. Document no.: EOC220601 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 8 p. (CEST rapid review report).
ECDC & WHO have released statements indicating that while a 4th dose may be beneficial to populations at highest risk of severe outcomes, marginal benefits for other populations may be outweighed by the opportunity and financial cost
Extensive analysis of data from Israel’s 4th dose campaign indicates that while protection against severe disease and death remains high following 3rd dose, the administration of a 4th dose significantly increases protection against infection and symptomatic disease, though this protection appears short-lived, with protective effects waning by 10 weeks
Israeli healthcare workers demonstrate an increase in immunity markers following 4th dose, but protection against infection remains low
In immunocompromised individuals (such as solid organ transplant patients and dialysis patients), receipt of a 4th dose of COVID-19 vaccine increases immunity marker titers, but non-responders continue to have a low likelihood of de novo seroconversion
March 31, 2022
Data from Israel of adults 60 years and older who received a 4th dose of mRNA vaccine found that the rate of confirmed infection decreased ~2 fold following the 4th dose, and the rate of severe illness decreased by ~4-fold in those who received a 4th dose versus those with 3 doses, both results were found to be statistically significant
NACI recommends a 4th dose at least 6 months following a 3rd dose for severely immunocompromised individuals who are not only at higher risk of severe outcomes, but also at higher risk of decreased protection over time following vaccination – this recommendation has been echoed by Public Health Ontario, the Northwest Territories Health and Social Services
The FDA has also authorized the use of the Pfizer mRNA vaccine as a 4th dose for adults over 50 years and those over 12 years with compromised immune systems
A small study of Israeli healthcare workers compared the incidence of COVID-19 in those who had received a 4th dose of vaccine to those who had received only three doses. It found that protection from Omicron infection was only slightly higher in the four-dose vaccine group compared to the three-dose control group (31% for Pfizer as a 4th dose, 11% for Moderna as a 4th dose), and that neither result was statistically significant. Breakthrough infections were mild, yet with high viral loads
Small-scale studies of solid-organ transplant and hemodialysis patients found that while a 4th dose increased antibody titers in most participants, those with severe immune deficiencies such as those taking anti-rejection medication were still unable to mount an immune response to vaccination – in addition, these studies have not assessed the presence or strength of functional immunity in these populations
Badea, A; Dalidowicz, M; Howell-Spooner, B; Groot, G; Reeder. B. What is the efficacy of a 4th booster dose for COVID-19? 2022 Jun 07. Document no.: EOC220304v002 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 12 p. (CEST rapid review report).
Current requirements for preoperative COVID-19 testing are highly variable across jurisdictions, with some requiring preoperative testing for all patients 24-72 hours prior to surgery and some not recommending testing of asymptomatic patients at all
Studies describing low rates of asymptomatic positivity are limited to early in the pandemic, prior to the widespread availability of vaccines and the emergence of variant strains. These studies show very low rates of asymptomatic positives when testing within 72 hours of surgery
Mixed evidence on safety of surgery in asymptomatic COVID-19 infected patients
Preliminary evidence indicates that it may be safe to discontinue asymptomatic preoperative testing, but there are too many unknowns that have not yet been addressed with regards to the impact of vaccination status and the altered pathophysiology associated with currently circulating variants
Badea, A; Groot, G; Reeder, B; Dalidowicz, M; Mueller, M. What is the evidence around testing for asymptomatic COVID on the day of surgery? 2022 Jun 06, Document no.: EOC220505 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 11 p. (CEST rapid review report).
There is substantial immunologic and increasing epidemiologic evidence that vaccination following infection further increases protection against subsequent illness among those who have been previously infected.
Laboratory studies indicate that hybrid immunity (i.e., immunity conferred by the combination of previous infection and vaccination) offers greater protection against COVID-19 infection.
A single dose of the AstraZeneca COVID-19 vaccine following SARS-CoV-2 infection induced a 2 to 3-fold increase in anti-Spike and -RBD IgG levels 30 days post-vaccination.
A study in Brazil found that hybrid immunity showed a modest increase in protection against symptomatic infection and waning over time.
Neutralising antibody titres against SARS-CoV-2 variants over 7 months following Pfizer vaccination in SARS-CoV-2-recovered and naïve healthcare workers resulted in substantially enhanced T-cell responses, anti-spike IgG responses and neutralising antibodies effective against SARS-CoV-2 variants in recovered participants.
Pfizer and Moderna vaccines were associated with greater IgG responses compared to Johnson & Johnson regardless of administration following infection.
Those with vaccine-after-infection or vaccine-breakthrough-infection had a more durable anti-spike-IgG response compared to infection-alone.
A study on healthcare workers from Oregon Health & Science University found enhanced immune responses after vaccination in COVID-19 recovered (hybrid immunity) compared with their naïve-vaccinated peers. However, the effects of post-vaccination breakthrough infections on humoral immune response remain to be determined.
Groot, G; Reeder, B; Muhajarine, N; Lee, S; Badea, A; Jagwani, M; Fox, L; Miller, L. What is known about hybrid immunity to COVID-19? 2022 Jun 06, Document no.: INF220501 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 11 p. (CEST rapid review report).
Significant evidence base demonstrates an increased risk of perioperative mortality in COVID positive surgical patients
Based on previous knowledge of preoperative pulmonary infections, as well as early clinical data, most professional associations recommend a deferral of at least 7 weeks from symptom onset or positive test to elective surgery
New evidence in light of the existing surgical backlogs indicates that those with asymptomatic or mild infections can proceed to minor, low-risk elective surgeries 4 weeks after symptom onset or positive test
Guidelines and frameworks indicate that timelines are only recommendations and individuals need to be assessed objectively for preoperative fitness, that the risks and benefits of both surgery and delay be discussed, and that shared decision making used between multidisciplinary care teams and patients
Badea, A; Groot, G; Reeder, B; Fox, L; Young, C. What is the evidence on timing and outcomes of elective surgery after a COVID infection? 2022 May 27, Document no.: EOC220504 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 11 p. (CEST rapid review report).
Recommendations for COVID-19 vaccination timing following monoclonal antibody or convalescent plasma therapy range from a precautionary 90 day deferral, to assessing on a case-by-case basis to no need for deferral
Only published evidence is a sub-study of the larger Bamlanivimab trial where prophylactic administration of Bamlanivimab prior to mRNA COVID-19 vaccination did not affect the immune response regardless of age, risk category or vaccine product used
No evidence currently exists for vaccination timing following the use of antiviral products such as Paxlovid or Remdesivir
Badea, A; Groot, G; Reeder, B; Dalidowicz, M; Mueller, M. Is there an optimal interval between the administration of COVID-19 early intervention therapeutic products and COVID-19 vaccination? 2022 May 10, Document no.: EOC220501 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 10 p. (CEST rapid review report).
Rowein S, Singh S, Habbick M, Mehdiyeva K, Miller L, Gagneur, A, Groot G, Neudorf C, Camillo CA, Tokhmafshan, F, Muhajarine N. Motivational Interviewing for Vaccine Hesitancy. May 2022. Document no.: [12.1]. CoVaRR-Net Public Health, Health Systems, Social Policy Team, c2022.
Novavax was authorized for use in Canada February 16, 2022 and has also been authorized for use in 35 other countries as a 2-dose primary series given as an intramuscular injection, 21 days apart
Phase 3 trials of Novavax in US/Mexico and UK showed an overall vaccine effectiveness of 89.7-90.4% against all severity COVID infection and 100% against moderate/severe infection and death
In the US/Mexico, vaccine effectiveness against the dominant Alpha variant was found to be 92.6%, while in the UK, it’s effectiveness dropped to 86.3%
The most frequently reported local and systemic adverse events in both trials were tenderness and pain at the injection site and headache, myalgia and fatigue, respectively. Adverse events were mild-to-moderate and transient in nature, and more frequently reported following the second dose
A Phase 2 trial assessing safety and efficacy of Novavax in South Africa in adults 18-64 years during Beta dominance found a vaccine efficacy of only 49.4%, however, in subgroup analysis of only HIV negative individuals, efficacy rose to 60.1% overall, and 51% against the Beta variant. (). While efficacy against disease severity was not measured, the majority of infections reported in both the vaccine and placebo group were mild to moderate
Badea, A; Groot, G; Reeder, B; Miller, L. What is the safety/efficacy of the Novavax COVID-19 vaccine? 2022 Mar 10. Document no.: EOC220302 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 7 p. (CEST rapid review report).
The CDC has released a recommendation that all adolescents 12-17 be offered booster vaccines using only the Pfizer COVID-19 vaccine, at least 5 months following the primary series
The CDC guidelines follow the review of unpublished Israeli data of 12-15 year olds vaccinated 5-6 months prior showing an equivalent infection rate to unvaccinated, and that those who receive boosters are at about 1/3 of the risk
Health Canada has not yet approved booster doses for general use in 12-17 year olds, however NACI has recommended that boosters, at least 6 months following the primary series, should be considered for the following groups within that age group
o Those with an underlying medical condition at high risk of severe illness due to COVID-19 (including those who are immunocompromised and received a 3-dose primary series)
o Those who are residents in congregate settings (e.g. shelters, group homes, quarters for migrant workers, correctional facilities)
o Those who belong to racialized and/or marginalized communities disproportionately affected by COVID-19
Updated Review cancelled due to insufficient evidence
Badea, A; Reeder, B; Groot, G; Dalidowicz, M; Fox, L. Is there evidence that children under 18 should receive the booster to increase their immunity? 2022 Feb 04, Document no.: EOC220102 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 8 p. (CEST rapid review report).