Coronavirus (COVID-19) vaccine certification: evidence paper

This paper summarises the range of evidence available on vaccination certification schemes. Evidence is drawn from clinical and scientific literature, from public opinion and from international experience.

This document is part of a collection

5. Introducing vaccine certification

5.1 The basis of certification

The COVID-19 vaccination certification scheme in Scotland aims to[93] [94] [95] [96]

  • Reduce the risk of transmission (harm 1);
  • Reduce the risk of serious illness and death and in doing so alleviate current and future pressure on the healthcare system (harm 1 and 2);
  • Allow higher risk settings to continue to operate as an alternative to closure or more restrictive measures (harms 3 & 4); and
  • Increase vaccine uptake (harm 1 and 2)

Scotland's COVID-19 vaccine certification scheme will act as proof that an individual has had both doses of a COVID-19 vaccine. The certificate will allow access to restricted higher risk settings. Certificates will be available as a QR code through the Scotland COVID-19 Status App or requested through a paper record of vaccination[97].

Scotland will be the only European country that will adopt a vaccine only certification scheme with no option to provide a negative PCR or antigen test result or proof of recovery from a previous COVID-19 infection within a predetermined time period.

In Scotland, an individual must have been "vaccinated with a Medicines and Healthcare products Regulatory Agency (MHRA) recognised vaccine in line with the MHRA recommended number of doses for the vaccine used and two weeks has passed for the vaccine to take effect"[98].

However, it should be noted that the UK Government have stated in their report 'COVID-19 Response: Autumn and Winter Plan' that a contingency 'Plan B' may be implemented that would include a vaccine certification scheme without the option to test negative or to provide proof of recovery from a previous COVID-19 infection within a predetermined time period[99].

Certain provinces in Canada have recently launched vaccine only certification schemes[100] [101] [102]. The vaccine only certification schemes allow access to high risk locations, such as indoor events, hospital, nightclubs and gyms. They do not provide the option of a recent negative test or proof of previous infection. Provinces include Quebec, Manitoba, British Columbia and Ontario all of which launched their schemes in September 2021[103] [104] [105] [106]. As these schemes only recently launched started, it is too early to say if they have been successful in reducing transmission or case numbers.

A variety of different criteria are used for COVID-19 status certification across the countries with schemes in place, see Table 2 for COVID-19 certification validity in Scotland and comparator countries.

Table 2: COVID-19 certification validity in Scotland and comparator countries. Correct as of 23 September 2021
Country Certification Name Certification Validity
Vaccination PCR test Rapid Antigen Test Recovery
Scotland[107] COVID-19 vaccination certification scheme Full +14 days Not included Not included Not included
Austria[108] Gruner Pass (Green Pass) Full (+22 days for J&J) 72h (Vienna 48h) 24h (Vienna certified only) 180 days
Belgium[109] COVID Safe Ticket Full +14 days 72h 48h 180 days
France[110] Pass sanitaire Full (+7 days or +28 for J&J) 48h 48h 6 months
Germany[111] CovPass/ Corona Warn App Full +14 days 48h 24h 6 months
Iceland[112] N/A – Testing scheme Not included Not included 48hr (Certified only) Not included
Ireland[113] COVID-19 certification scheme Full (+ additional days depending on vaccine) Not included Not included 6 months
Israel[114] Green Pass Full (currently updating to include booster) 72h 24h 6 months
Italy[115] Certificazione verde (Green Pass) Full or partial 48h 48h 6 months
Netherlands[116] Corona Check Full +14 days (+28 days for J&J) 24h 24h 6 months
Norway[117] COVID-19 certificate Full or partial +3 weeks 24h 24h 6 months
Wales[118] (From 11 October) Full Not included in announcement 48h Not included in announcement

The strictness of vaccination status eligibility ranges from partial vaccination in Italy, to fully vaccinated with additional waiting time in Germany and Belgium[119] [120] [121]. Other countries certification schemes also accept negative PCR or rapid antigen tests as proof of negative COVID-19 status.

Duration of certification based on negative COVID-19 status is more limited compared to vaccination status, with negative PCR test validity ranging from 24 hours in the Netherlandsand Norway, 48 hours in France, Germany and Italy, and up to 72 hours in Austria, Belgium and Israel[122] [123] [124] [125] [126] [127] [128] [129].

Other countries also accept proof of COVID-19 recovery as a means to demonstrate COVID-19 secure status. For example, France's certificate (pass sanitaire) includes individuals who had previously tested positive through rapid antigen testing or PCR testing, provided the test is more than 15 days old but less than 6 months old[130].

EMG/SPI-M/SPI-B have noted that certification based on vaccination status or prior infection would indirectly reduce the likelihood of an infected person being present as they would demonstrate some level of immunity. Certification to prove vaccination or prior infection can reduce the risk of severe illness but is not yet certain whether it will reduce transmission of infected people. EMG/SPI-M/SPI-B note that certification based on negative test results could reduce the likelihood of an infected person being present but would depend on the quality of the test and when the test was taken in relation to the event. They note that the practical and ethical issues need to be considered[131].

There are no real life studies directly comparing certification schemes based on testing only, vaccination (or previous infection) only, or both. LFD testing is effective at identifying people with the virus when they are at their most infectious and have high viral loads[132]. A large study in England found that the sensitivity at high viral loads was the same (88%) whether administered by experienced or inexperienced users[133]. A consensus view of vaccines effectiveness against infection or symptomatic disease in fully vaccinated people is between 60-90%, depending on the vaccine[134]. Evidence is not available on which type of certification scheme (testing or vaccination) would be most effective at reducing the likelihood of infected people being present at an event.

5.2 Activities requiring certification

COVID-19 certification is in widespread use in European countries such as Austria, France, Germany, Israel and Italy where restricted settings include indoor hospitality, leisure facilities and gyms.

See Table 3 for restricted activities requiring COVID-19 certification in Scotland and comparator countries.

Table 3: Restricted activities requiring COVID-19 certification in Scotland and comparator countries. Correct as of 23 September 2021
Country Certification Name Restricted activities
Indoor hospitality Leisure facilities Contact professions Indoor events Outdoor Events Nightclubs Gyms Hospitals Domestic travel
Scotland[135] COVID-19 vaccination certification scheme Y Y Y (late night venues)
Austria[136] Gruner Pass (Green Pass) Y Y Y Y Y Y Y
Belgium[137] COVID Safe Ticket (From 1 October 2021)[138] Y Y Shut
France[139] Pass sanitaire Y Y Y Y Y Y Y Y Y
Germany[140] CovPass/ Corona Warn App Y Y Y Y Y Y Y Y
Iceland[141] N/A – Testing scheme Y Y
Ireland[142] COVID-19 certification scheme Y Y Y Y Shut Y
Israel[143] Green Pass Y Y Y Y Y Y
Italy[144] Certificazione verde (Green Pass) Y Y Y Y Shut Y Y Y
Netherlands[145] Corona Check Y Y Y Y Shut
Norway[146] COVID-19 certificate Y Y
Wales[147] (From 11 October) Y Y Y

EU countries with certification include events (indoor and/or outdoor) of varying sizes within their certification schemes, ranging for up to 1000 indoor in the Czech Republic to 75,000 in Belgium[148] [149] [150] [151] [152] [153] [154] [155] [156] [157] [158] [159] [160] [161] [162] [163] [164] [165] [166]. In Ireland, since 20 September 2021, when multiple cohorts have mixed immunity status at indoor events, uncertified individuals are allowed to enter in 'pods' of 6, with social distancing protective measures in place[167]. In Iceland, both indoor and outdoor events are allowed up to 500 with no certification and up to 1500 with certification[168].

In France and Italy domestic certification is also used for domestic travel, while in France and Germany it is used to enter hospital settings and in France public facing employees must be fully vaccinated or provide proof of a negative antigen test within a defined period of time.

5.3 The impact of certification on vaccine uptake

There have been a range of reasons for the introduction of COVID-19 certification in other countries[169]. France, Belgium and Germany introduced certification in response to increasing case numbers. Belgium aimed to use the certificates to avoid the reinstatement of social restrictions[170]. France and Israel introduced certification to drive vaccine uptake, hoping that by restricting access to desirable events more people would take up the vaccine[171] [172] [173].

The impact of vaccine certification in Israel is unclear, as announcements were followed by protests and confusion; however, case rates declined allowing Israel's economy to begin reopening[174]. In Denmark the main stated goal was to encourage regular testing among unvaccinated people and certification was linked to the overall health situation rather than vaccine uptake. In the week beginning 16 April 2021, following the launch of certification on the 14April, a record 1 million people were tested, roughly 1 in 4 adults, many getting tested several times a week[175]. The high rates of testing peaked on 12 May 2021 with 33.70 per 1000 but drastically dropped since then, averaging 6.27 per 1000 on 19 September 2021[176]. From 10 September, Denmark discontinued the use of their mandatory domestic COVID-19 vaccine certificate scheme, Coronapas with around 77% of all adults over 12 fully vaccinated they consider the epidemic to be currently under control[177] (weekly case rates in Denmark up to 16 September were 48.77 per 100k compared to 530.6 per 100k in Scotland)[178].

In Spain certification has not been introduced, Spain's central government cited its relatively high vaccine uptake for not requiring a certification scheme and instead prioritises vaccination as the key strategy to tackle COVID-19[179]. However, regional governments have started to consider the use of COVID-19 certifications. In Galicia, following a favourable Supreme Court ruling, the implementation of a scheme for hospitality and late night venues will now proceed[180]. In Catalonia, the government is exploring the possibility of introducing the scheme as a way of reopening indoor hospitality and late night venues[181]. The Valencian Government will initiate a dialogue with the hospitality and event sectors with a view of introducing a scheme from 9 October[182].

The percentage of the total population that was vaccinated when certification schemes were announced also varies significantly between countries, ranging from 3% of the total population in Denmark to 68% in Belgium[183]

In Scotland 75% of the total population (90% of adult population) had received at least one dose of a vaccine on 1 September when the announcement of vaccine certification scheme was made[184] [185]. Significant uptake of a first dose of vaccine was noted immediately after the Scottish Government announced their intention to introduce a vaccine certification scheme in the 16-17 age groups respectively, as seen in Table 4. In the five days after the announcement, an increase was seen in first dose uptake, peaking at an 81.3% increase on day 4 compared to the day of the announcement. Total vaccination uptake hasn't seen the same level of increase. With the total vaccination uptake in the 7 days after the announcement being at 75% of the 7 days prior. However, Scotland is starting at a higher vaccine level than comparator countries[186] [187].

Table 4: Vaccination rates in Scotland
Dose 1
Age group 1 September 17 September Change (percentage points)
16-17 50.9% 66.4% 15.5
18-29 74.5% 75.9% 1.4
30-39 82.4% 83.1% 0.7
40-49 91.0% 91.4% 0.4
Under 40s 76.4% 78.4% 2.0
Dose 2
Age group 1 September 17 September Change (percentage points)
16-17 8.6% 9.4% 0.8
18-29 52.6% 61.1% 8.5
30-39 71.3% 73.7% 2.4
40-49 84.9% 85.9% 1.0
Under 40s 57.9% 63.2% 5.3

COVID-19 certification schemes, including vaccine certification have been implemented in different countries, with a mixed response on vaccine uptake (Figure 11).

Figure 11: Daily vaccinations administered per 100 people, 10 days prior and 30 days after the initial announcement of COVID-19 certification.
Chart shows that following the announcement of certification, a large increase in vaccine uptake is seen in Israel, peaking at about 2.1 per 100 people. No clear trends seen for other countries. Date of certification announcement is given: Belgium, 20 July; Israel, 15 January; Netherlands, 9 April; Italy, 22 July; Germany, 27 July; France, 12 July; Scotland, 1 September. Percentage of population vaccinated at time of announcement also given: Belgium, 68%; Israel, 24%; Netherlands, 16%; Italy, 61%; Germany, 61%; France, 53%; Scotland, 75%.

Sources for dates of announcement for France[188], Italy[189], Scotland[190], rest from ICJU (unpublished). % of population vaccinated at time of announcement given[191]

From: Coronavirus (COVID-19) Vaccinations - Statistics and Research - Our World in Data. COVID-19 Daily Dashboard | Tableau Public Updated 21 September 2021.

Israel announced that they would be introducing a COVID-19 certification pass on 15 January. On that day, the number of people vaccinated against COVID-19 was 2.11 million (24% of the 18+ population), this increased to 2.72 million (32%) 10 days after the announcement on 25 January. Daily vaccine doses administered per 100 people over this period were 0.79 on 15 January and 2.11 on 25 January. Therefore a 100% increase was observed in daily doses administered over the 10 day period after the announcement was made, however this is a correlation, rather than proof of effectiveness of the scheme. The proportion of people vaccinated against COVID-19 with at least one dose of vaccine over 10 days period after the announcement day rose from a low level of 24% to 31%[192].

Appointments in Italy increased by 200% in some regions in the following months after the announcement[193].

In Ontario where a vaccine only certificate was introduced, "The proof of vaccination policy has resulted in a marked increase in vaccination rates. Between September 1 and September 8, 2021, the seven-day average for first doses administered increased by more than 29 per cent, from over 11,400 doses to over 14,700 doses. During that time, more than 90,000 first doses and 102,000 second doses were administered in Ontario to individuals aged 18 to 59"[194].

Comparator countries first announced certification at different stages of their vaccination rollout and epidemic. Belgium, Germany and Netherlands have seen little to no change in vaccination uptake rates after announcements. A range of other factors such as vaccine supply and cohort eligibility are also likely to affect situation differently in each comparator country.

France introduced certification to drive vaccine uptake by restricting access to desirable events[195]. In the first few weeks after the introduction of vaccine/immunity certificates in France an increase in vaccination rates was reported, with 4 million being vaccinated in the 2 weeks after the announcement[196]. Vaccination rates per 100 people increased from 0.85 on July 12 2021 to 1.03 on 21 July 2021[197]. Since this initial peak, daily vaccination rates have dropped to 0.34 per 100 people on 15 September 2021[198]. There have also been numerous demonstrations against vaccine certification since the announcement was made[199] [200].

Notably France introduced an update to their certification scheme on 30 August whereby all staff with face to face interactions with the general public are required to be fully vaccinated or have tested negative for the virus in the last 72 hours. This is thought to affect around 1.8 million workers[201].

Italy have also announced the introduction of certification to public and private work from the 15 October 2021. This includes all staff of public administrations, holders of elective offices and institutional offices, those who work in the private sector and administrative staff and magistrates with judicial offices[202].

5.4 The impact of certification on transmission risk

As described in Section 3, vaccinated people are less likely to become infected and so less likely to infect others, therefore vaccination prevents transmission at large events by reducing the likelihood of infected people being present.

There is limited evidence to date that vaccine certificates alone result in a reduction in transmission at events given the difficulties in linking specific cases to specific venues. However by encouraging more people who attend higher risk venues to become vaccinated the transmission risk will be reduced. This is particularly important in the absence of other mitigations in such venues, for example physical distancing or the wearing of face masks, which would be alternative ways of reducing transmission.

There is some evidence that COVID-19 certification based on test results as well as vaccination status can be open to manipulation. The Netherlands implemented COVID-19 certification for nightclub entry on 26 June, 2021. Despite attempts to prevent unauthorised access unvaccinated and untested individuals were still able to gain entry due to end-user errors and oversight[203]. Subsequent rises in cases led to the closure of nightclubs again[204]. However, the government is currently developing support measures for nightclubs and discos to try to reopen[205].

Media reports increasingly note the problem of fake certificates[206] [207] [208]. Some countries have implemented fines and prosecution for individuals found using counterfeit certificates and for businesses found not to be checking certificates[209] [210].

5.5 The interaction of certification and event capacity

The UK Government's Events Research Programme, set up to examine the risk of transmission of COVID-19 from attendance at mass events, has completed the 3 phases of the research. Details can be found at Information on the Events Research Programme - GOV.UK (

During Phase I of the programme all attendees were required to provide a negative lateral flow (rapid) test before they could enter each event. They were also asked to take a voluntary PCR test before and after the event, however there was a low return rate of 15%). At the time, virus prevalence was low and together with the low rate of testing before and after events, it was not possible to draw conclusions on the effectiveness of the testing scheme[211].

Results from the Phase III showed that the highest percentage of all the infections connected to various mass events came from the eight European Football Championship EURO 2020 games involved (June – July 2021). Researchers concluded that;

"Whilst some of this may be attributed to a set of circumstances which are unlikely to be replicated for the forthcoming sporting season, other aspects may be important to consider including mitigations for spectators to consider such as face coverings when travelling to and from events and minimising crowding in poorly ventilated indoors spaces such as bars and pubs where people may congregate to watch events"[212].

Another risk mitigating measure recommended was promoting vaccination during high community prevalence as this reduces the number of people who are potentially infectious or at risk when entering the venue without the necessity to limit the attendance.

Four events have been associated with higher numbers of cases (over 1,000). These are the UEFA, European Football Championships 2020 final (Italy vs England, 11 July, 2021) and one of the semi-finals (England vs Denmark, 7 July, 2021), Latitude Music Festival and Tramlines Festival. These events all took place during a period of higher underlying community prevalence[213] [214]. The UK government's analysis of the Phase III findings concluded that mass events can take place safely as case numbers were largely in line with or below community infection rates, but fans are urged to remain cautious in crowds and encouraged to get vaccinated.

Preliminary findings have been reported from a study 'Limiting Virus Transmission during Sporting Mega Events (LIVE)' project by researchers from the University of Stirling and Loughborough University. They analysed COVID-19 mitigation measures and behaviours of fans that attended matches at Hampden Park, Glasgow or Wembley Stadium, London during the UEFA European Football Championships in June – July 2021 using trained supporters to collect data via structured observations. The study recommended that several improvements could be made to assist future large scale events including providing clearer instructions of the mitigation measures in place to attendees prior to the event[215]. They all suggested that proof of identification to be included as part of the protocol if testing or vaccination status was required, see Annex D for further details.



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