Flu shots may fail to offer sufficient protection this year and cause many more people to fall ill, after coronavirus emergency measures hindered research on influenza.
Scientists said they feared that the reduction in research on dominant variants, notably a 62 per cent drop in the international transportation of flu samples, could lead to a medicine mismatch.
In February, the World Health Organisation recommended the ingredients to be used in vaccines administered in the Northern Hemisphere.
But vaccine makers say that globally, the genetic sequencing of flu variants had fallen by up to 94 per cent before the ruling was made.
“We saw quite a big reduction in the labs supplying the genetic sequence data to WHO, and around September last year, we saw a 94 per cent drop in the genetic sequence data that was reported into the database. So this has had a massive impact in the reporting,” said Dr Beverly Taylor, at vaccine maker Seqirus, which provides Britain with seasonal flu vaccines.
“We could have reduced the opportunity to identify viruses as they emerge. We certainly have reduced the opportunity to look at which viruses would give the best overall protection and the best coverage of all the circulating viruses.
“What we’re actually seeing is influenza in geographical pockets, so it’s very difficult for us to tell which one is going to be the winner. We could potentially see a mismatch for at least one of the subtypes. And so that’s cause for concern.
“This winter, it’s going to be over 18 months since most of us have seen influenza and there is concern that we’ll see a lower level of population immunity.”
Thousands of deaths
Since the pandemic began, many laboratories that usually provide flu data have switched to researching Covid-19.
The Academy of Medical Sciences said it estimated that between 15,000 and 60,000 people in the UK could die of flu this winter. A mismatched vaccine could make the situation worse, it said.
“In years with mismatch, [vaccine] effectiveness against both infection and severe disease can be markedly reduced, resulting in more severe epidemics,” the authors wrote.
“Given the global decrease in influenza circulation, there has been much less information available on which to base predictions about which influenza strains will circulate this winter.
“As such, there is an increased likelihood that there will be influenza vaccine mismatch this winter, which could result in more infections and disease.”
Public Health England said the failure to provide an effective flu vaccine during the winter of 2014 to 2015 may have contributed towards a spike in deaths.
Figures on fatalities of all causes published by the Office for National Statistics showed 28,189 more people died in England and Wales in 2015 than in the previous year, the largest percentage increase since 1968.