Introducing vaccine certificates to control entry to public venues increases vaccine uptake, found the first large-scale study on the impact of a certificate system.
The Oxford University study, published in The Lancet Public Health, reported an increase in the number of people receiving vaccinations 20 days before the certification system started and up to 40 days thereafter. The study was done in Denmark, Israel, Italy, France, Germany and Switzerland.
The types of venues in which a certificate requirement was introduced determined which age groups experienced higher numbers of vaccines, said Oxford sociology professor Melinda Mills, the study’s lead author.
“Increase in uptake was most pronounced in people under 30. When restrictions were applied to only nightclubs and large events, the largest increases were among under-20s,” she said. When restrictions were expanded to include all hospitality and leisure settings, uptake also increased among 20- to 49-year-olds.
Apart from helping to curb the spread of the virus, said the authors, “COVID vaccine certification could also help increase uptake in vaccine-complacent groups, like younger people”.
They said implementation should be considered in the context of circumstances such as vaccination coverage, vaccine hesitancy, levels of trust in authorities and the pandemic trajectory.
According to Mills, “as mass vaccination programmes continue to play a central role in protecting public health in this pandemic, increasing vaccine uptake is crucial both to protect the individuals immunised and break chains of infection in the community”.
In countries where vaccine coverage was previously low, “introduction of certification was associated with a significant increase in the number of additional vaccine doses per million people”.
Co-author Tobias Rüttenauer said it is important to remember, however, that certification alone “is not a silver bullet for improving vaccine uptake and must be used alongside other policies”.
With no indication yet about the composition and timeline for a task team to look into mandatory vaccines in certain public spaces and workplaces, SA Health Department spokesperson Foster Mohale told the Sunday Times: “Our role is to enable organisations that wish to verify the vaccination status of their customers or employees to do so with a certificate as a verifiable document. We don’t decide who must impose compulsory vaccination.”
Study details
The effect of mandatory COVID-19 certificates on vaccine uptake: synthetic-control modelling of six countries
Professor Melinda Mills, Tobias Rüttenauer
Published in The Lancet Public Health on 13 December 2021
Summary
Background
Mandatory COVID-19 certification (showing vaccination, recent negative test, or proof of recovery) has been introduced in some countries. We aimed to investigate the effect of certification on vaccine uptake.
Methods
We designed a synthetic control model comparing six countries (Denmark, Israel, Italy, France, Germany, and Switzerland) that introduced certification (April–August, 2021), with 19 control countries. Using daily data on cases, deaths, vaccinations, and country-specific information, we produced a counterfactual trend estimating what might have happened in similar circumstances if certificates were not introduced. The main outcome was daily COVID-19 vaccine doses.
Findings
COVID-19 certification led to increased vaccinations 20 days before implementation in anticipation, with a lasting effect up to 40 days after. Countries with pre-intervention uptake that was below average had a more pronounced increase in daily vaccinations compared with those where uptake was already average or higher. In France, doses exceeded 55 672 (95% CI 49 668–73 707) vaccines per million population or, in absolute terms, 3 761 440 (3 355 761–4 979 952) doses before mandatory certification and 72 151 (37 940–114 140) per million population after certification (4 874 857 [2 563 396–7 711 769] doses). We found no effect in countries that already had average uptake (Germany), or an unclear effect when certificates were introduced during a period of limited vaccine supply (Denmark). Increase in uptake was highest for people younger than 30 years after the introduction of certification. Access restrictions linked to certain settings (nightclubs and events with >1000 people) were associated with increased uptake in those younger than 20 years. When certification was extended to broader settings, uptake remained high in the youngest group, but increases were also observed in those aged 30–49 years.
Interpretation
Mandatory COVID-19 certification could increase vaccine uptake, but interpretation and transferability of findings need to be considered in the context of pre-existing levels of vaccine uptake and hesitancy, eligibility changes, and the pandemic trajectory.
See more from MedicalBrief archives:
Vaccine passports are about stopgap practicalities, not human rights
COVID-status certificates may be discriminatory — UK rights watchdog
SAHRC says mandatory vaccination constitutional but not desirable