The first real-world data for COVID-19 vaccines is in – and the vaccines’ effectiveness have once-again shot past scientists’ expectations, according to reports.
Vaccines are typically less effective in the real-world than in clinical trials. But in data from Israel and the United Kingdom, both of whom have managed to vaccinate a large slice of their population, vaccine effectiveness appears to be matching that seen in clinical trials.
There are also positive signs the vaccines will significantly cut viral transmission, although it is too early to draw firm conclusions.
In Britain, Pfizer’s mRNA vaccine appears to be 88 per cent effective at preventing symptomatic infection in those aged over 80.
Israeli scientists are reporting a 92 per cent effectiveness rate overall – similar rates to those seen in clinical trials that initially stunned scientists.
Israel and Britain are among world leaders in vaccinating their populations. Israel has managed to give one dose to least 56 per cent of its population, while in Britain about 30 per cent of people have received at least one jab.
Both countries faced surging epidemics only a month ago, but daily cases have now been substantially curtailed.
The US has also made strong headway, reducing its daily caseload from a peak of 314,172 on January 8 to 66,481 on March 4. About 16 per cent of the US’s population had received a dose of vaccine.
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However, these countries’ success was likely linked to more lockdowns and perhaps the end of winter, rather than the effects of vaccination, said James Wood, associate professor at the School of Population Health at the University of NSW.
Britain went into a national lockdown at the start of January, while Israel’s national lockdown started at the end of December. Israel’s progress appears to be plateauing, however, even as restrictions are eased.
Vaccine efficacy describes how well a vaccine works in a clinical trial. But a vaccine’s effectiveness – how well it works in the real world – is a different matter.
Vaccine trials enrol select groups of patients. Pfizer’s phase 3 trial, for example, excluded patients with uncontrolled chronic medical conditions.