The diagnostic accuracy of Rapid Antigen Tests (RAT) has been widely studied in various applications and in diverse populations.
Sensitivity, in the order of 75% in pooled estimates, is significantly influenced by the presence or absence of symptoms, viral load, and the timing of sampling relative to the onset of symptoms.
Specificity, in the order of 99% in pooled estimates, is consistently high across tests, populations, and sampling methods.
Post-test probability of being an infectious case following a positive test is highest in individuals with a high pre-test probability (population prevalence > 5%), such as those with COVID-19 symptoms, and those in settings with a high level of community transmission. Here, the positive predictive value is in the order of 95%. However, when used in settings with a lower pre-test probability (population prevalence < 0.5%), as in screening asymptomatic individuals, the positive predictive value is considerably reduced, as low as 25%.
Post-test probability of being an infectious case following a negative test is less than 1% (negative predictive value > 99%) in all settings except those with the highest levels of community transmission.
Badea, A; Reeder, B; Groot, G; Muhajarine, N; Minion, J; Miller, L; Howell-Spooner, B. In real world settings, what is the validity of Rapid Antigen Tests (RATs) in identifying SARS-CoV-2 and how well do they predict disease? 2022 Jan 12, Document no.: EOC211201 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2022. 15 p. (CEST rapid review report).
Requiring proof of vaccination for entry into another country is not a new idea. There are regulations that need to be followed to set up a “vaccine passport” in relation to international travel (International Health Regulations (IHR) (2005))
At present the World Health Organization does not recommend vaccine passports for international travel, but they are working on a standard Smart Vaccination Certificate technical specification and standards to allow for harmonised processes to include COVID-19 vaccines into an updated version of the IHR (2005)
Countries around the world are beginning to put vaccine passports into place for international travel, as well as in some countries within country travel and access to services or businesses including Israel, France, Italy, Denmark, and the EU
The Canadian Federal government is supportive of a vaccine passport for international travel but recognize the issuing of vaccine passports will need to be province led
As of May 13, 2021, the province of Quebec has begun issuing a downloadable QR code that individual can keep on their smart phone.
As of June 9, 2021, the Federal government of Canada discussed easing restrictions for fully vaccinated Canadian citizens returning to the country
Ethical considerations in the use of vaccine passports include equitable access to vaccination (domestically and internationally), access to technology (eg. Smartphone passports), marginalization, or stigmatization especially among historically racialized groups, and socially isolated populations
Legal considerations include
o Clarifying who has the legal authority to require proof of vaccination,
o Ensuring that if new legislation is created and implemented it is in line with all pre-existing legislation (Charter of Rights and Freedoms, Human Rights Codes, privacy legislation, employment legislation),
o Ensuring that, if created by the government, there is coordination of the Provincial and Federal governments for international travel with respect to jurisdictional overlap, security of information, fraud
Health care facilities should be able to legally enact vaccination policies for patient-facing employees so long as they allow for exemptions due to medical inability or bona fide religious, or conscientious beliefs
Six in ten Canadians (61%) expect vaccine passports to be widely used in Canada by the end of 2021, the same proportion (61%) of Canadians also agreed that only vaccinated people should be allowed to engage in events involving larger crowds such as public transit, air travel, or attending cultural and sports events
Lashta E, von Tigerstrom B, Reeder B, Groot G; Miller, L; Mueller, M. What are the ethical/legal aspects of vaccine requirements? 2021 Jun 21, Document no.: EOC210503 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 25 p. (CEST rapid review report).