More than one in five EU citizens have had Covid-19 since the start of the pandemic, according to a new estimate.
The modelling suggests that about 94 million people in the bloc have been infected at some stage – more than three times the number of confirmed cases.
During the first wave in Europe in the spring of 2020, testing was scarce in many countries and the official figures were a significant underestimate.
But even in the age of mass testing, only about 43 per cent of infections are being detected, the study by the Institute for Health Metrics and Evaluation at the University of Washington in the US said.
The IHME's findings also suggest that Europe could be at the peak of its third wave of the pandemic.
Scientists say the combination of vaccines, lockdown measures and the seasonal effect of spring should be enough to reduce infections, hospital admissions and deaths in the EU’s 27 countries.
“It is possible that this week marks a watershed for the EU as a whole, with a peak in daily cases and deaths,” they said.
Blamed on the variant of Covid-19 first detected in the UK, the third wave forced several countries – including France and Germany – to impose new lockdowns.
Germany last week ordered its strictest measures yet, with ministers ordering 10pm curfews in many areas after the federal government in Berlin seized control from Germany's states.
However, several countries plan to ease restrictions in the coming weeks – raising fears of a resurgence in cases.
Scientists in Belgium, Switzerland and Italy have warned against a premature lifting of restrictions.
European countries are accelerating their vaccination programmes after a slow start, with nearly a quarter of EU citizens now having had a first dose.
Some governments are giving only one dose to people who have recovered from Covid-19 in the past, because they already have antibodies.
In addition, a previous recovery from Covid-19 is one of the ways that EU citizens will be able to prove they are safe to travel under a "digital green certificate" scheme unveiled by Brussels.
An infection within the past 180 days would eliminate the need for a vaccine or a negative test, under the proposals agreed this month by EU ambassadors.
The IHME modelling suggests that 21 per cent of the EU's 447 million population were infected at some stage during the pandemic.
However, most of these people would be unable to prove this because they never tested positive for the disease.
Europe watches India's Covid-19 crisis with alarm
Meanwhile, fears are growing in Europe about the possible impact of the crisis in India and the B.1.617 variant that could be fuelling the resurgence of the disease.
Health officials are also monitoring the spread of the variants first identified in South Africa and Brazil, which concerned officials because of their possible impact on vaccine efficacy.
The IHME’s modelling lays out a “worst scenario” in which a variant spreads out of control in Europe just as mobility and social contacts pick up again.
Such a scenario could lead to an additional 24,000 deaths across the EU, the study says.
The UK imposed a travel ban on India last week and Germany followed suit on Saturday after designating the country as a "virus variant zone".
"We're very worried about the new mutation of the virus discovered in India,” German Health Minister Jens Spahn told German media.
“So as not to endanger our vaccination programme, India travel has to be significantly limited".
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