Table 5 Impact of COVID-19 vaccine certificates on willingness to vaccinate

Increased willingness to vaccinate (n = 12)

[31]

Increase in log-odds of COVID-19 vaccination if vaccine certificates were made available in the U.S. (among total survey respondents)

0.318

(95% CI: 0.254–0.381)

Subgroup analysis: vaccine certificates increased vaccine uptake among respondents who want one by log-odds of 0.383 (95% CI: 0.304–0.463), but did not affect uptake among respondents who do not want certificates (log-odds: –0.049; 95% CI: –0.160; 0.258)

[22]

Increase in prevalence of survey respondents “willing to accept” the COVID-19 vaccine if government-mandated vaccine certificates were implemented (in the Netherlands)

22.1 p.p

Prevalence increased from 47.5% (baseline) to 69.6% (if vaccine certificates were implemented)

[28]

Increase in prevalence of COVID-19 vaccine uptake (first doses) after government-mandated vaccine certificates to access to public and non-essential business venues

Increases in vaccination rate compare “actual” vs. “counterfactual” estimates

Germany

4.7 p.p. (90% CI: 4.1–5.1 p.p.)

Recorded at 11 weeks post-announcement; equivalent to 3.47 (90% CI: 3.06–3.81) million new first doses

Canada

Up to 5 p.p. (90% CI: 3.9–5.8 p.p.)

Recorded at 5–13 weeks post-announcement across provinces; equivalent to 979,000 (90% CI: 425,000–1,266,000) new first doses

France

8 p.p. (90% CI: 4.3–10.8 p.p.)

Recorded at 16 weeks post-announcement; equivalent to 4.59 (90% CI: 2.47–6.25) million new first doses

Italy

12 p.p. (90% CI: 5–15.1 p.p.)

Recorded at 14 weeks post-announcement; equivalent to 6.48 (90% CI: 2.67–8.14) million new first doses

[29]

Increase in prevalence of COVID-19 vaccine uptake (first doses) after government-mandated vaccine certificates to access to public and private venues

Increases in vaccination rate are comparing “actual” vs. “counterfactual” estimates

Germany

6.2 p.p. (95% CI: 2.6–6.9 p.p.)

Prevented an estimated 1,133 deaths and GDP loss of €1.4 billion in Germany

Italy

9.7 p.p. (95% CI: 5.4–12.3 p.p.)

Prevented an estimated 1,331 deaths and GDP loss of €2.1 billion in Italy

France

13.0 p.p. (95% CI: 9.7–14.9 p.p.)

Prevented an estimated 3,979 deaths and GDP loss of €6.0 billion in France

[32]

Prevalence difference in survey respondents “intending to accept” COVID-19 vaccination if vaccine certificates helped relax all public health restrictions, compared to no relaxation of restrictions (in Japan)

27%

Among vaccine-hesitant respondents, 45% intended to get vaccinated if vaccine certificates relaxed COVID-19 public health restrictions, compared to 18% if they are not relaxed

Increase in prevalence of survey respondents “intending to accept” COVID-19 if vaccine certificates helped relax specific restrictions (in Japan):

Travel across prefectures

10 p.p. (95% CI: 9–11 p.p.)

Subgroup analysis:

Among younger (aged < 45): 11 p.p. (95% CI: 9–13 p.p.)

Among vaccine-ambivalent: 15 p.p. (95% CI: 14–16 p.p.)

Among vaccine-hesitant:

3 p.p. (95% CI: 2–4 p.p.)

Dining out after 8 pm

6 p.p. (95% CI: 5–7 p.p.)

Subgroup analysis:

Among younger (aged < 45): 7 p.p. (95% CI: 6–8 p.p.)

Among vaccine-ambivalent: 9 p.p. (95% CI: 8–10 p.p.)

Among vaccine-hesitant:

3 p.p. (95% CI: 2–4 p.p.)

Join social gatherings/events

4 p.p. (95% CI: 3–5 p.p.)

Subgroup analysis:

Among younger (aged < 45): 4 p.p. (95% CI: 3–5 p.p.)

Among vaccine-ambivalent: 6 p.p. (5–7 p.p.)

Among vaccine-hesitant:

1 p.p. (0–2 p.p.)

Going out without masks

7 p.p. (95% CI: 6–8 p.p.)

Subgroup analysis:

Among younger (aged < 45): 7 p.p. (95% CI: 6–8 p.p.)

Among vaccine-ambivalent: 10 p.p. (95% CI: 9–11 p.p.)

Among vaccine-hesitant:

4 p.p. (95% CI: 3–5 p.p.)

[30]

Absolute increase in COVID-19 vaccine doses 20 days prior to the introduction of vaccine certificates (in anticipation):

Increases in vaccine doses are comparing “actual” vs. “counterfactual” estimates using 19 control countries. Denmark and Germany were analyzed, but changes were non-significant

Israel

-31,485 (95% CI: -489,267; -31,485)

This is equivalent to -3,582 (95% CI: -55,663; -3,582)

doses per million population

Switzerland

153,152 (95% CI: 31,851–221,482)

This is equivalent to 17,572

(95% CI: 3,655–25,412)

doses per million population

Italy

2,513,065 (95% CI: 1,505,684–3,207,418)

This is equivalent to 41,629

(95% CI: 24,942–53,132)

doses per million population

France

3,761,440 (95% CI: 3,355,761–4,979,952)

This is equivalent to 55,672

(95% CI: 49,668–73,707)

doses per million population

Absolute increase in COVID-19 vaccine doses within 40 days post-introduction of vaccine certificates:

Increases in vaccine doses are comparing “actual” vs. “counterfactual” estimates using 19 control countries. Denmark and Germany were analyzed, but changes were non-significant

Israel

2,168,728 (95% CI: 1,925,688- 2,364,362)

This is equivalent to 246,733

(95% CI: 219,083–268,990)

doses per million population

Switzerland

412,940 (95% CI: 86,021–685,270)

This is equivalent to 47,380

(95% CI: 9,870–78,627)

doses per million population

Italy

1,494,270 (95% CI: 72,366–4,475,654)

This is equivalent to 24,753

(95% CI: 1,199–74,140)

doses per million population

France

4,874,857 (95% CI: 2,563,396–7,711,769)

This is equivalent to 72,151

(95% CI: 37,940–114,140)

doses per million population

[24]

Prevalence of survey respondents that cited the EU COVID certificate as the reason to receive COVID-19 vaccination (in France)

36.2% (n = 72/199)

In contrast, 22.6% (n = 45/199) of respondents cited that the EU COVID certificate did not influence willingness to vaccinate

[26]

Perceived influence of vaccine certificates for overseas travel on a sliding scale from 0 (not impactful) to 10 (most impactful) (in China)

4.44 out of 10

(95% CI: 4.18–4.71)

Vaccine certificates for overseas travel was the highest-rated facilitator to COVID-19 vaccination

[33]

Participants that cited COVID-19 vaccine certificates as a reason for receiving vaccines (in the United Kingdom)

N/A

(Qualitative study)

Vaccine certificates could ‘nudge’ vaccine delayers to vaccinate for travel, work, and social purposes

[34]

Unvaccinated participants cited that the use of COVID-19 vaccine certificates resulted in a positive influence for vaccination

39%

76% of the population measured strongly supported the implementation of a vaccine passport

[35]

Increase in COVID-19 vaccine uptake with the introduction of a vaccine passport

13.98% in Poland, and 19.75% in Lithuania

3.88% of those 80 year old (vaccinated individuals) or older were convinced

In unvaccinated:

26.10% of those aged 18–24, 26.89%in the 25–49 age group, 27.47% of those aged 50–59, 22.98% in the 60–69 group, and 16.89% in the 70–79 group, but only 8.14% of those aged 80 and more

[36]

Increase in COVID-19 vaccine uptake with the introduction of a vaccine passport

British Columbia

4.4p.p. (95% CI 2.1–6.6)

This is equivalent to to 203,300 (98,253–308,346) more people being vaccinated

Alberta

8.2p.p. (95% CI 7.0–9.4)

This is equivalent to to 310,890 (267,169–354,611)

more people being vaccinated

Saskatchewan

7.2p.p., 95% CI 5.3–9.1)

This is equivalent to 71,711 (52,337–91,084) more people being vaccinated

Manitoba

5.4p.p. (95% CI 4.0–6.9)

This is equivalent to 63,936 (46,841–81,030) more people being vaccinated

Nova Scotia

5.2p.p. (95% CI 1.6–8.8)

This is equivalent to 44,054 (14,052–78,056) more people being vaccinated

Newfoundland and Labrador

6.4p.p. (95% CI 3.8–9.0)

This is equivalent to 29,814 (17,542–42,086) more people being vaccinated

Ontario

No significant change

Quebec

No significant change

New Brunswick

No significant change

Prince Edward Island

Decreased vaccine uptake^**

Decreased willingness to vaccinate (n = 1)

[23]

Prevalence of survey respondents who declared they may reconsider their wish to be vaccinated if national QR code-based vaccine certificates are implemented (in Russia)

26.59%

Vaccine uptake in Russia followed an exponential increase except for two major periods of slowdown (August 23–October 20, 2021; and November 25–January 15, 2022), which correspond to time periods when Russian QR code-based vaccine certificates were introduced

Mixed findings or no effect (n = 3)

[25]

Predicted impact of COVID-19 vaccine certificates on vaccine uptake (based on logistic regression analysis) (in Israel)

OR: 1.12

(95% CI: 0.82–1.55)

Vaccine certificates had a positive impact on vaccine uptake, but non-significant

[39]

Impact of public messaging about the benefits of owning COVID-19 vaccine certificates on willingness to vaccinate

France

OR: 0.87

(95% CI: 0.46–1.63)

Messaging had a negative impact on vaccine uptake, but non-significant

Sweden

OR: 0.92

(95% CI: 0.66- 1.27)

Messaging had a negative impact on vaccine uptake, but non-significant

Poland

OR: 0.97

(95% CI: 0.61–1.54)

Messaging had a negative impact on vaccine uptake, but non-significant

Italy

OR: 0.97

(95% CI: 0.71–1.34)

Messaging had a negative impact on vaccine uptake, but non-significant

Spain

OR: 0.97,

(95% CI: 0.96–1.36)

Messaging had a negative impact on vaccine uptake, but non-significant

Germany

OR: 1.44

(95% CI: 1.09–1.91)

Messaging had a positive impact on vaccine uptake and was significant

United Kingdom

OR: 1.51

(95% CI: 1.11–2.05)

Messaging had a positive impact on vaccine uptake and was significant

Bulgaria

OR: 1.58

(95% CI: 0.67- 3.73)

Messaging had a positive impact on vaccine uptake, but non-significant

[27]

Prevalence difference of survey respondents that were “inclined to accept COVID-19 vaccines” if vaccine certificates are introduced for domestic use (in the U.K.)

Responses were given on a 5-point ordinal scale: much less inclined, somewhat less inclined, no more or less inclined, somewhat more inclined, and much more inclined

Much less inclined

6.41%

(95% CI: 5.61–7.38%)

Somewhat less inclined

4.08%

(95% CI: 3.66–4.54%

No more or less inclined

46.5%

(95% CI: 44.4–48.7%)

Somewhat more inclined

14.9%

(95% CI: 14.4–15.5%)

Much more inclined

28.1%

(95% CI: 25.3–31.1%)

Prevalence difference of survey respondents that were “inclined to accept COVID-19 vaccines” if vaccine certificates are introduced for international use (in the U.K.)

Responses were given on a 5-point ordinal scale: much less inclined, somewhat less inclined, no more or less inclined, somewhat more inclined, and much more inclined

Much less inclined

5.61%

(95% CI: 4.86–6.34%)

Somewhat less inclined

3.95%

(95% CI: 3.52–4.35%)

No more or less inclined

42.0%

(95% CI: 39.8–43.9%)

Somewhat more inclined

14.9%

(95% CI: 14.6–15.2%)

Much more inclined

33.6%

(95% CI: 30.8–36.6%)