With the reopening of the economy and the lifting of coronavirus restrictions, the pandemic-hit health systems in Europe and the United States are ready to deal with a widespread flu outbreak this winter.
This year, lockdowns and travel restrictions have almost eradicated the disease in the southern hemisphere, but Lynnette Brammer, head of the domestic influenza surveillance team of the US Centers for Disease Control and Prevention, warned that “the virus is there-they have not disappeared. Leave.”
She added: “It’s just a question,’As travel returns to normal, will they spread? The possibility of increased flu activity definitely exists, and we are watching what happens.”
On the other side of the Atlantic, concerns about the prospects are also clear. Chris Whitty, the chief medical adviser to the British government, warned that if the country’s taxpayer-funded medical services face a “flu surge” from viruses and other respiratory diseases, “the coming winter may be quite difficult”.
Epidemiologists usually pay attention to countries such as Australia and New Zealand, where the flu season usually peaks in August to understand what might happen in other parts of the world in a few months. However, this year, the country’s health department has only received notifications of 417 influenza cases and not a single death.
According to the World Health Organization, as many as 650,000 people die each year from respiratory diseases related to seasonal influenza, with an average of 3,500 Australians.
Ian Barr, deputy director of the WHO Influenza Reference and Research Collaboration Center, said: “The basic situation is that we cannot detect the influenza that is circulating in Australia. As far as I know, no virus has been detected in New Zealand this year.”
In this regard, Covid-19 has brought unexpected benefits: the same measures taken to suppress it — city blockades, border closures, and isolation of returning citizens — almost completely eradicated seasonal flu in the hemisphere.
South Africa has also counted a very small number of influenza cases. The country’s National Institute of Infectious Diseases Uncover By the end of June, there were only 50 cases in the main areas and no deaths. Experts believe that a series of measures have been taken to prevent the spread of Covid-19, including extensive restrictions on foreign travel due to the spread of local variants of the virus.
The disease has not completely subsided. Bramer of the CDC said that H3N2 cases-part of the influenza A virus most commonly associated with severe flu seasons-are spreading in Asia, while China has recorded “a significant amount of influenza B activity.”
In Africa, the main virus circulating this year is H1N1, which caused the first pandemic in more than 40 years in 2009.
The worry now is that after such a long period of calm, people may not be prepared to fight the flu. Barr said: “The longer the season without influenza, the lower the level of herd immunity.”
John McCauley, director of the World Influenza Center at the Francis Crick Institute in London, pointed out that if the number of cases does increase, 18 months have passed since the last major outbreak.
“We start from the low point [of infections] But the immunity of the population is low. I think we are in a position where we cannot really predict what will happen. You just need to take steps to keep it as low as possible by increasing vaccination,” he said.
Macaulay said that early signs of the use of sera from infected persons indicate that the current flu vaccine may be effective against the influenza B virus circulating in China.
However, its handling of the H3N2 strain is “not very good, this is a problem,” he added, while emphasizing that the vaccine has only been tested under laboratory conditions and may perform better in the real world.
However, even the best flu vaccine is only about 60% effective, while the first-generation coronavirus vaccine has an effectiveness level of more than 90%.
Macaulay suggested that behind some of the most effective Covid-19 vaccines, new mRNA technologies may be deployed to improve the performance of influenza vaccines in the next few years, although a lot of work is needed to develop them.
Nick Wilson, a professor of public health at the University of Otago in New Zealand, said one of the lessons learned from the coronavirus pandemic is that “seasonal flu is more controllable than we thought in the past.”
However, doing so may depend on whether people are willing to continue to limit the social restrictions of Covid-19. He added that, for example, it is not clear whether society believes that “it is worthwhile to require regular masks to be worn on public transport and in healthcare settings every winter.”
Brammer said that as people start to mix in large numbers, the CDC is paying close attention to how the virus reappears, noting that the number of respiratory syncytial virus cases in the United States continues to increase during the summer, which can be serious for young children or the elderly.
She added: “We always say that the flu is very unpredictable, and I think it has never been more real than it is now. We may have a severe flu season, or we may just be an ordinary flu season.
“But one thing I am confident about is that the flu will start to spread again.”