Debora MacKenzie is the author of COVID-19: The Pandemic that Never Should Have Happened and How to Stop the Next One.
In a few months, the Northern Hemisphere will head into flu season – and COVID-19 will still be here. How do we handle both at once?
More than six months in to the COVID-19 pandemic, and we are all used to hearing that nothing is certain. But here are two things that are as close to certain as infectious diseases ever get.
One: COVID-19 will not just disappear by winter.
Two: We will also have a flu epidemic this winter, like we always do. The big uncertainty now keeping epidemiologists and hospital managers awake is this: How on earth will we manage both at once?
Just ordinary flu, and the other winter viruses, will be bad enough alongside COVID-19. What happens if flu pulls one of its regular identity switches, and stages a pandemic of its own, this winter or next year, while economies and health care systems are still reeling from COVID-19?
It is all too possible. In the past six weeks, both Chinese and European researchers have warned that strains of potentially pandemic flu have emerged in pigs, while bird flu, which hit headlines in the 2000s, has never gone away.
But there is a ray of hope. We may not have a COVID-19 vaccine yet, but we may soon get one to handle the flu.
Every fall a series of viruses rage through the world’s temperate zones. First a common cold, rhinovirus, sets in as small children go back to school and exchange mucus. As that subsides, respiratory syncytial virus or RSV, the biggest cause of pneumonia in babies, takes over. Then the annual wave of flu sweeps in from East Asia.
Having one of them often stops you being infected by the others, but none of them seem to deter COVID-19. Doctors in New York and California have found all the usual autumn viruses in coronavirus patients. Wuhan doctors found patients with both flu and COVID-19 were not more likely to die, but did have more heart damage and earlier runaway inflammation, the late-stage immune reaction that kills many COVID-19 victims.
The coming Northern Hemisphere winter will be the world’s first full-on collision between these epidemics. In the Southern Hemisphere, with winter now under way, anti-COVID-19 lockdowns and physical distancing have slowed flu to a trickle. When Hong Kong locked down for COVID-19 last February, it stopped its continuing flu epidemic in its tracks.
But Northern Hemisphere countries such as Canada are unlikely to return to such strict lockdowns this winter, so we will get them all full on. And because of the way flu travels in its yearly excursions, less flu in the south will not mean less flu in the north this winter, says Colin Russell of the University of Amsterdam.
The problem for doctors this winter will be diagnosing people with a fever and cough, as those are typical in both flu and COVID-19. Moreover both viruses make exactly the same people especially sick and likely to seek medical care: people over the age of 60, or with medical conditions involving inflammation, such as high blood pressure, diabetes or obesity.
Hospitals can be swamped just in a bad flu year. On average, 12,200 Canadians are hospitalized due to flu every winter, and 3,500 die. Now there will be coronavirus cases adding to the flu cases, and people with both will be more seriously ill.
Managing the different infections will be difficult. Medical staff can be vaccinated for flu, but they need full personal protective equipment (PPE) to deal with COVID-19. They may need full PPE for every patient until test results allow them to separate people with just flu. Even that will take new resources, as we don’t normally test all incoming flu patients.
Tim Sly, an epidemiologist at Ryerson in Toronto, sees two problems. “Having folks with flu lining up at the testing centre with COVID suspects,” he says, means more people will need testing to find the COVID-19 cases. And people may swap viruses while waiting.
On the other hand, “People with early COVID may think they only have a cold or flu,” so they may not get tested or isolate. “All the more reason to get the flu shot this season as soon as it’s available.” That alone poses logistical problems: COVID-19 precautions such as physical distancing will be needed by staff administering the shots.
The vaccine can help. Danuta Skowronski, an epidemiologist at the University of British Columbia, reports that this year 60 per cent of Canadians who got their flu shot last fall were protected.
But this is variable. Flu constantly evolves, so you need a new vaccine every year. And as there is little profit in them, vaccine makers still mostly use a technique from the 1940s, which takes six months. That means they had to predict last February what flu would circulate this winter, and what vaccine virus to grow. Sometimes they are right, sometimes less so.
This also means that, even though we should vaccinate more people than usual to minimize the dual impact of flu and COVID-19, manufacturers cannot make more vaccine now. Canada recommends flu vaccination for everyone over six months old, but only 42 per cent of Canadian adults got it in 2018-19.
Vaccine stocks ordered for this winter will reflect this demand. This year people could well want far more, but there will be no more vaccine.
And all bets are off if a flu pandemic hits. This is when a human flu emerges that has proteins from an animal flu that most humans have not encountered before, as virologists fear may happen with pig flu in China or Europe.
People have far less immunity to pandemic flu than to normal winter flu, and it can be much more deadly. Existing vaccines normally don’t affect it at all.
One vaccine could fix these problems: a universal flu vaccine that immunizes you to small bits of the virus that are the same in all flu, ordinary or pandemic. In theory, one shot should immunize you to whatever flu turns up, while the vaccine can be stockpiled for emergencies when demand increases, unlike any vaccine we have now.
Many companies are working on these, but there has been little funding for the big expensive trials needed to see if they work, as no company sees much profit in one-shot flu vaccines. But an Israeli company, BiondVax, got European Union support for the first-ever big trial of a candidate universal flu vaccine last year, and will announce the results soon. If it worked, the company says it can build production plants and churn out large amounts of vaccine, quickly.
We need it quickly. A flu pandemic is inevitable and can happen any time. More immediately, with more flu vaccine we could stop more people at high risk from COVID-19 from also getting ordinary winter flu, and keep our health care systems from buckling under severe cases of both viruses – if not in time for this winter, then perhaps next year.
With the world frantically working on COVID-19 vaccines, flu may seem a distraction. But the way the two could collide this winter shows starkly that the COVID-19 problem isn’t about just one virus. It is about our vulnerability as a tightly interconnected, global species to infectious disease, both new and familiar.
We need to seriously up our game every way we can to fight back.
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