Low grade evidence shows IgG and IgM antibody response correlates with neutralizingantibody titerand viral clearance, which is suggestive of protective humoral immunity inCOVID-19 patients with mild to moderate symptoms.
There is no available evidence with which to estimate the durability of this protective response. However, if the immune response to SARS-CoV-2 resembles that toward SARS-CoV, this protective humoral immunity may persist for several years.
Higher IgG antibody titersand a robustresponse were noted in severe to criticallyill patients and were associated with lower viral clearance and a worse clinical prognosis.
Low grade evidence suggests that convalescent plasma treatment may improve the clinical status of critically ill COVID-19 patients(one case series with only five patients enrolled).
Duncan, V. At what time in the disease timeline of COVID-19 do antibodies develop? 2020 Apr 14; Document no.: LAB041402-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 42 p. (CEST evidence search report)
Vanstone, J; Reeder, B; Duncan, V. At what time in the disease timeline of COVID-19 do antibodies develop? 2020 Apr 15; Document no.: LAB041402 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 4 p. (CEST rapid review report)
Duncan, V. What sampling method is most appropriate for population testing? 2020 Apr 23; Document no.: LAB042201-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 14 p. (CEST evidence search report)
Howell-Spooner, B. What frequency of repeat population screening will be required? 2020 Apr 23; Document no.: LAB042202-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 40 p. (CEST evidence search report)
For COVID-19 there are no published data to identify optimal population sampling methods, however, a population-based sample in which testing is performed for both rt-PCR and serology might be recommended. There are also opportunities to examine innovative sampling strategies being used in pilot studies underway in other jurisdictions.
Vanstone, J; Reeder, B; Duncan, V. What sampling method is most appropriate for population testing? 2020 Apr 23; Document no.: LAB042201 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 5 p. (CEST rapid review report)
Low grade evidence suggests that SARS-CoV-2 may persist within a population and lead to recrudescent outbreaks in winter months which may include the re-infection of previously infected individuals.
· Population monitoring by means of repeated cross-sectional surveys and/or longitudinal cohort studies is strongly advised by WHO
Wang, H; Reeder, B; Howell-Spooner, B. What frequency of repeat population screening will be required? 2020 Apr 25; Document no.: LAB042202 RR. In: COVID19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020.
4 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)
Howell-Spooner, B. What proportion of disease transmission is due to asymptomatic, pre-symptomatic and symptomatic cases? 2020 May 8; Document no.: LAB040701v2-01 ESR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 25 p. (CEST evidence search report)
