In October, WHO released a consensus definition of post COVID-19 condition that includes 12 domains. This development should lead to better standardization of reporting and contribute to more precise prevalence estimates and better understanding of associated risk factors.
The effects of Variants of Concern (VoC) and COVID vaccination on progression of Long COVID symptoms remains unclear.
Risk factors for developing Long COVID symptoms were similar but limited evidence suggests that pre-pandemic psychological distress and poor general health were associated with developing persistent symptoms. Evidence is too limited to determine whether vaccination reduces the risk of developing Long COVID among persons with breakthrough infections.
Given the protean manifestations of Long COVID symptoms, the underlying causes are likely multifactorial; however, strong evidence to substantiate the theories of causation remains limited.
Research related to longer-term consequences of SARS CoV-2 infections in pediatric populations is growing but remains limited.
March 15, 2021
There is a lack of consensus around the clinical definition of Long COVID which in turn causes challenges with understanding the incidence and prevalence as well as the potential impact for the health care system
Information about the natural history of Long COVID is incomplete but limited evidence suggests that the immune response trajectories differ for those with few or no symptoms compared to those with severe disease. Individuals with severe disease are more likely to exhibit immunological marker abnormalities but anyone can experience functional limitations.
The mechanisms underlying the development of persistent symptoms in Long COVID remain an enigma. Despite multiple theories, there is little empirical evidence for specific immunological and or biochemical abnormalities in samples of individuals with symptoms consistent with Long COVID.
Risk factors for Long COVID include female gender, older age, higher body mass index, pre-existing asthma and the number of symptoms.
Few studies explored the short-term impact of Long COVID on health care utilization patterns and found a higher impact for those with severe disease compared with mild disease.
Williams-Roberts, H; Groot, G; Mueller, M; Dalidowicz, M. Long COVID: What does it mean for the healthcare system and programs? 2021 Oct 29. Document no.: EOC021901v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 14 p. (CEST rapid review report).
August 18, 2021
- Proof of vaccine “freebies” to customers are slowing
- Many vaccine “lotteries” have now ended with prizes being given out, retrospective analysis of vaccine numbers and assumptions regarding causality will likely follow in the near future
- More state-sponsored incentives such as partnerships with ride-share companies, childcare centers, etc.
- Post-secondary institutions offering incentives mostly in the form of raffles with grand prizes of cash/scholarships for staff/students with proof of vaccination
- ESN evidence synthesis found 8 systematic reviews providing some evidence of positive impact of financial incentives with or without other interventions for non-COVID-19 vaccines, 3 reviews found no effect
- Several European countries (Greece, France, Italy) mandating vaccination for healthcare workers with refusers facing sanctions/fines/suspensions/job loss
- Ontario requiring hospitals, licensed care homes and other high-risk settings such as post-secondary institutions, women’s shelters, youth care facilities, etc. to establish vaccination policies – while vaccination will not likely be mandatory, those who are not vaccinated will be subject to frequent antigen testing.
- In Pakistan, the government will be blocking the SIM cards of vaccine refusers, and allowing business to resume in areas with a vaccination rate of greater than 20%
- In Indonesia, vaccine refusers will have any social aid suspended and face fines
- In the Philippines, the President is threatening to find ways to legalize arresting and forcing vaccination for refusers
- A retrospective analysis of vaccination data in Israel found a peak of 2nd dose vaccinations correlating with the exemption of quarantine for vaccinated individuals beginning January 17th, and high rates continued following the day with the highest new daily cases as well as the day of highest fatality rates
- Israeli survey of 500 individuals found that 21% of respondents were not intending to vaccinate. The implementation of the ‘Green Pass’ would possibly or definitely convince 31% of respondents, but 46% of respondents indicated that it would not.
May 27, 2021
Vaccine incentives are beginning to emerge in North America in various forms due to a lagging vaccine uptake combined with the threat of SARS-CoV-2 variants
Vaccine incentives range from free items and discounts offered by businesses to customers to financial incentives offered by companies to employees such as paid time off or cash bonuses
Some states/provinces have developed vaccine incentive programs offering large lotteries with cash prizes or scholarship awards, cash incentives or offers for free/discounted entertainment options
Some incentives are specifically geared to high priority populations, for example offering gift cards to anyone within a certain age demographic that receives a vaccine at certain sites, or offering the single-dose Johnson & Johnson vaccine at walk-up vaccination sites in subway stations with the addition of free transit passes
Badea, A; Reeder, B; Groot, G; Ellsworth, C. What are other jurisdictions offering for incentive-based COVID-19? 2021 Aug 24, Document no.: EOC210501v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 10 p. (CEST rapid review report).
Generally speaking, data indicate that adult cancer patients and those who have recently received or are receiving anti-cancer therapy are at a higher risk of severe outcomes and death resulting from COVID-19 compared to those without cancer. However, more data are beginning to elucidate the nuances of these risks depending on patient specific factors.
Limited data indicate that pediatric cancer patients are not at a high level of risk of severe outcomes from COVID-19.
Limited evidence indicates some differences in the course and severity of SARS-CoV-2 infection depending on the type of immunosuppressive therapy a patient receives.
Generally speaking, data indicate that adult cancer patients and those who have recently received or are receiving anti-cancer therapy are at a higher risk of severe outcomes and death resulting from COVID-19 compared to those without cancer.
Pediatric cancer populations may not be at the same level of risk as adult populations.
There is not enough evidence at this time to determine if there are differences in the course of SARS-CoV-2 infection in patients receiving chemotherapy vs. those who are not aside from outcomes and severity.
Vanstone, J; Groot, G; Miller, L; Mueller, M. What are the differences in the clinical course of COVID-19 between patients undergoing chemotherapy and otherwise healthy individuals? 2021 Jan 22; Document no.: EOC062201v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 5 p. (CEST rapid review report)
· First confirmed case of reinfection documented in a 33 year-old man in Hong Kong, who was first infected with the virus in March, and again while on holiday in Spain four and a half months later – though asymptomatic for both infections
· Genetic sequencing has identified a small number of reinfection cases with different strains
· No concrete evidence on the presence and/or duration of immunity to SARS-CoV-2 in humans
· Demonstration of PCR positivity does not necessarily indicate continued or renewed infection; it may indicate the presence of a dead virus.
· In-vitro analyses have documented the presence of SARS-CoV-2 antibodies in convalescent samples up to eight months post infection
· Only one small study in rhesus monkeys recovered from SARS-CoV-2 were not re-infected when re-challenged with SARS-CoV-2 upon recovery
· Many cases series of previously recovered SARS-CoV-2 patients re-testing positive following clinical and pathological recovery, but virus has been unable to be cultured from those patients, most remain asymptomatic and there have been no documented secondary cases arising from patients following positive re-tests
Badea, A; Lee, S; Groot, G; Takaya, S; Dalidowicz, M; Howell-Spooner, B. What is the duration of immunity for COVID-19 in previously infected patients? 2021 Jan 20; Document no.: INF090101v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 26 p. (CEST rapid review report)
Badea, A; Groot G; Dalidowicz, M; Young, C; Miller, L. What are the recommendations around settling times following aerosol generating procedures on suspected or confirmed COVID-19 patients? 2020 Dec 1; Document no.: EOC081401v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 24 p. (CEST rapid review report)
Badea, A; Lee, S; Shumilak, G; Dalidowicz, M. What is the risk of reinfection from COVID-19? 2020 Nov 2; Document no.: EOC032401v3 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 13 p. (CEST rapid review report)
Several references provide estimates of the proportion of HCW infected with SARS-CoV2 that range from 0.9% -20%. A recent review from Alberta Health Services that examined the COVID-19 rt-PCR test results among HCW indicates that in that province 2.4% of physicians and 0.9% of non-MD HCW who were tested were positive for SARS-CoV-2 compared to 3.5% of the general population.
In the studies reviewed, the majority of cases are confirmed by RT-PCR, while only one reference also used serology testing.
Vanstone, J; Reeder, B; Duncan, V; Howell-Spooner, B. What proportion of healthcare workers are rt-PCR positive and IgM or IgG positive? 2020 Jun 2; Document no.: LAB040802v3 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 10 p. (CEST rapid review report)
Vanstone, J; Reeder, B; Duncan, V. What is the relationship between antibody development and viral shedding and infectiousness? 2020 May 19; Document no.: LAB041601v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 5 p. (CEST rapid review report)
COVID-19 is primarily transmitted by symptomatic patientsand presymptomatic individuals.·Moderate grade evidence estimates that approximately 20% of COVID-19 transmission may bedue to that from presymptomatic individuals.However, estimates range from 6.4% -47%.·Asymptomatic individuals and environmental contaminationappear to contributelessto disease transmission,with estimated proportionsof 6% and 10%, respectivelyfrom modelling studies
Wang, H; Reeder, B; Howell-Spooner, B; What proportion of disease transmission is due to asymptomatic, pre-symptomatic and symptomatic cases? 2020 May 8; Document no.: LAB040701v2 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 12 p. (CEST rapid review report)