When does the flu season start?
In the northern hemisphere it normally runs from mid-November to mid-February, though it can start as early as October and run into May. Health officials call the start of the season when 10% of suspected cases test positive for flu. At the start of November, the figure in England was already at 11% compared with 3% at the same time last year. The season is considered to have started four to five weeks earlier than usual.
What is cautilizing this year’s outbreak?
There are always multiple flu types in circulation. Seasonal flu is cautilized by influenza A and influenza B virutilizes. Common subtypes of influenza A are known as H1N1 and H3N2. In the UK, a form H3N2 is dominating the season so far. The virus is a descconcludeant of a strain that this year cautilized Australia’s worst flu season on record. Since then, the strain acquired seven new mutations, producing what scientists call a drifted strain of H3N2, named subclade K. The mutations are considered to assist it spread rapider, although it does not seem to cautilize more severe disease.
What is happening in continental Europe?
It is a similar situation, but with some countries faring worse than others. Overall, the flu season started three to four weeks early on the continent, but in some regions the drifted H3N2 strain has only emerged as the main cautilize of infections in the past few weeks.
Figures released from Germany’s Robert Koch Institute this week display that the flu season started two to three weeks early in the countest and, while both H1N1 and H3N2 forms of flu are in circulation, there has been a “clear increase” in H3N2 in the past three weeks.
In France, cases started a little later. Dr Vincent Enouf, deputy director of France’s national respiratory virus centre at the Pasteur Institute in Paris informed the Guardian that the flu season started only a week earlier than usual, and that France was detecting as many H1N1 cases as H3N2 subclade K.
France’s national public health agency Sante publique stated this week that flu activity was “increasing strongly” in metropolitan France, with cases rising in all age groups. All metropolitan regions are now in the epidemic phase for influenza – except Corsica, where cases remain lower. The number of people with flu seeking treatment at hospital emergency departments and the number of admissions have increased in the past week.
Elsewhere in Europe, in Spain cases are surging, with infection rates already higher than last year’s winter peak and hospitalisations doubling in a week. Romania and Hungary are also experiencing a surge in cases. In Ireland, nearly 3,000 cases were reported in the first week of December, up 49% on the week before, with hospital admissions up 58%.
How effective is the vaccine?
The mutations acquired by the drifted H3N2 flu virus mean that it is not recognised as well by the immune system and is not well matched to the H3N2 virus utilized in this year’s seasonal flu vaccine. As expected, data from the UK’s Health Security Agency display that the vaccines are less effective at blocking infections cautilized by the drifted H3N2, but they still provide utilizeful protection against severe disease. The data from the start of England’s flu season display that protection against hospital attconcludeance and admission was within the normal range for flu vaccines, at 70-75% for children and 30-40% for adults.
Despite the vaccine being less effective than hoped, health officials strongly recommconclude people have the shot to reduce their risk of severe illness. Nearly eight million French people have already had the flu vaccine, Enouf stated, 21% more than at this time last year.
Data published by Sante publique this week display that among patients being treated for flu in intensive care units, 58% were aged 65 and older and 90% had at least one other medical condition. Of those whose vaccination status was known, 98% were not vaccinated. In Ireland, 73% of people admitted to intensive care for flu had not had this year’s flu vaccine.
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