On September 22, 2021, FDA authorized an additional (booster) dose of Pfizer-BioNTech vaccine =6 months after completion of the primary series among persons aged =65 years, at high risk for severe COVID-19, or whose occupational or institutional exposure puts them at high risk for COVID-19.
Health Canada has updated the AstraZeneca (Vaxzevria) and Janssen COVID-19 vaccine product monographs to include information on Thrombosis with Thrombocytopenia Syndrome (TTS) or Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT).
The new SARS-CoV-2 Rapid Risk Assessment published on September 30, 2021 by the European Centre for Disease Prevention and Control (ECDC) stated that the EU has not yet achieved high enough COVID-19 vaccination coverage in their total populations (only 61.1% vaccinated) to relax restrictions as there is considerable variation in vaccine uptake across countries, resulting in large proportions of the EU/EEA population remaining susceptible to infection.
The ECDC also recommended that: “Vaccination against seasonal influenza, particularly for vulnerable populations and healthcare workers, will be essential to mitigate the impact on individuals and on healthcare systems in the coming months from the potential co-circulation of the two viruses.
Pfizer Inc (PFE.N) said on September 27, 2021, it has started a large study testing its investigational oral antiviral drug for the prevention of COVID-19 infection among those who have been exposed to the virus.
September 24, 2021
The Joint Committee on Vaccinations and immunization (JCVI) in the UK give a precautionary approach regarding vaccination of children aged 12 to 15 years who do not have underlying health conditions.
A prospective study has shown that the use of a booster dose (third dose, 5 months after full vaccination) with Pfizer (BNT162b2) substantially reduces the rate of confirmed COVID-19 infection and severe illness among individuals 60 and older.
Canada's National Advisory Committee on Immunization released recommendations on September 10th 2021 to provide a third vaccine dose to immunocompromised and populations with serious immunodeficiencies.
The JCVI is advising booster vaccines be offered to those more at risk from serious disease such as residents in care homes, adults aged 50 years or over, frontline HCW, individuals with underlying health conditions and adult household contacts of immunosuppressed individuals.
Long COVID-19 is likely to increase healthcare demands across the health system, including emergency departments, hospital admissions, primary care visits, specialists appointments, and home care and rehabilitation services.
The clinical care burden of long COVID-19 is the greatest in the first 3 months after testing and is likely to place the greatest demand on primary care services.
Patients with severe COVID-19 illness are more likely to place longer-term demands (4-6 months) on specialist care due to respiratory, circulatory, endocrine, metabolic, psychiatric and unspecified conditions.
McLean, M; Williams-Roberts, H; Reeder, B; Howell-Spooner, B; Ellsworth, C. What are long COVID's demands on the healthcare system, and its severity of the illness? 2021 Jul 12, Document no.: EPM210602 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 23 p. (CEST rapid review report).
The frequency of Long COVID symptoms varies widely across studies based on populations studied, duration of follow up and methods of assessment of symptoms.
It is estimated that 1 in 50 persons experience Long COVID symptoms after 12 weeks; however, higher estimates up to 80% have been reported in studies with a greater proportion of persons who were previously hospitalized. A recent study of a mixed cohort of 96 persons found that only 22.9% had no symptoms at 12 months post diagnosis.
A wide range of symptoms affecting multiple organ systems has been reported. For many persons symptoms improve over time while others experience persistent and/or new symptoms. Among studies with the longest duration of follow up, the most frequently reported symptoms included fatigue (up to 65%), dyspnea (up to 50%), headache (up to 45%), anosmia/ageusia (up to 25%), cognitive memory/concentration (up to 39.6%) and sleep disorders (up to 26%).
Few studies estimated the duration of symptoms with estimates ranging from 2.2% for 6 months and 27% for 7-9 months.
The mechanism(s) leading to Long COVID remain unclear but those experiencing post acute sequelae tend to be older, have a greater number of symptoms during the acute phase of illness or manifest specific symptoms and live with multiple comorbid conditions such as obesity.
The lack of consensus on a definition of Long COVID contributes to marked variations in robust prevalence estimates.
Williams-Roberts, H; Groot, G; Reeder, B; Howell-Spooner, B; Ellsworth, C. What is the incidence and duration of Long COVID cases? 2021 Jul 09, Document no.: EPM210601 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 19 p. (CEST rapid review report).
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; Reeder, B; Linassi, G; Basran, J; Dalidowicz, M; Mueller, M. Long COVID: What does it mean for the healthcare system and programs to deal with it? 2021 Mar 15; Document no.: EOC021901 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 37 p. (CEST rapid review report)
The majority of studies show elderly persons (>65 years) have significantly longer COVID-19 incubation periods compared to younger adults with a mean difference of +3.9 days (Lieu J et al. 2020; Kong TK et al. 2020; Jiang et al. 2020; Guo et al. 2020). One study showed no difference between those >60 years and younger patients (Lian et al. 2020).
Median incubation period across all studies (all ages) was 5 days (5.4 days mean). Jiang et al. (2020) report a mean incubation period of 7 days for younger adults and 10.9 days for those over age 65.
Upper limit of incubation period is 12-14 days with one study reporting 27 days (Nanda et al. 2020).
Median duration from symptom onset to death is 11.5 days in persons >70 years vs. 14 days in younger adults (Geriatric Emergency department collaborative March 2020).
Older age and more severe infections are associated with higher viral loads; however, viral shedding is not associated with infectivity. (European Centre for Disease Prevention and Control, 2020).
Doubling time of COVID-19 among residents from a single long-term care home was estimated to be 3.4 days compared to 5.5 days in the general population in the surrounding county (Arons et al. 2020).
Infected patients over the age of 65 years remain contagious for a significantly longer period (22 days vs. 19 days, p=0.015; Ziao et al. 2020).
Viral shedding may be longer for immune compromised patients (BC CDC 2020).
Symptom duration varies by nature of the symptom with a median time from diagnosis to discharge from hospital ranging from 13 days (range = 7-17; Ki et al. 2020) to 18.5 days (range = 11-27; Kim et al. 2020).
There is limited information on basic reproduction number in older adult populations. These values vary by region and over time. R0 values for whole populations (all ages) have been reported as low as 0.48 (Ki et al. 2020) to 2.5 (Lewnard et al. 2020)
Please see related reports by the Laboratory Working Group available in the SHA COVID-19 repository (not specific to elderly).
o LAB041601 RR Antibody development, viral shedding and infectiousness.
o LAB040701-01 RR Proportion of disease transmission due to asymptomatic, pre-symptomatic and symptomatic cases.
Tupper, S; Ward, H; Dalidowicz, M; Ellsworth, C. What is the incubation period, rate of spread, and duration of infectivity of COVID-19 in older adults? 2020 Jun 19; Document no.: LTC060202 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 28 p. (CEST rapid review report)