Things are getting better but no one really knows why
Tom Whipple
The Times
August 22, 2020
At the beginning, when beds were full and deaths common, doctors were still trying to understand the best treatment for coronavirus. “In March, if you came in and had trouble breathing, you’d be put straight on a ventilator,” says Alison Pittard, dean of the Faculty of Intensive Care Medicine.
This was what, in frantic Zoom calls to Italy and China, they had been told was the best approach. The learning curve since then has been steep.
These days, Dr Pittard and her colleagues are more careful about who is put on ventilators, lest invasive treatment causes more problems. They also have a drug, dexamethasone, that can significantly improve survival among those who do reach ventilators.
It would be easy to claim that we are seeing the results of this. In Britain, even as recorded cases rise, deaths are not following. In the western world daily deaths and death rates are falling.
But Dr Pittard is not prepared to take credit on behalf of her colleagues. “Yes, the way we manage patients has changed,” she says. “But I don’t think that has had much impact on mortality.” Some statisticians have argued that the effect is an illusion, created by more testing. She disagrees, at least to the extent that more tests explain everything. “Something does appear to have changed. We don’t know for certain what that is at the moment.”
She has a theory though. It may not be that the disease has altered, or that treatment has. It could simply be that the people getting it have.
“I think the group of people who are being infected is different now,” she says. One explanation, favoured by Dr Pittard, is that the virus has already claimed the lives of those most at risk.
“I think the more susceptible people have got the virus and been sick with it,” she said. “Now the people who are getting it respond in a different way.”
Another, not necessarily mutually exclusive, suggestion was put forward this week by Dr Takeshi Kasai, a senior World Health Organisation official.
Covid-19, a disease of the old, is becoming an infection of the young. “People in their twenties, thirties and forties are driving the spread,” he said. “The epidemic is changing.”
In Britain, as the number of Covid-19 patients on ventilators continues to drop, from more than 3,000 to 70, infection rates have risen by 35 per cent among the under-44s. In Australia, the Philippines and Japan, more than half of new infections are now in the young.
In continental Europe too, where rising cases have not been matched by rising deaths, it seems like we are seeing a breaking of this year’s fragile social contract - that the young, who don’t get sick, are increasingly refusing to suffer on behalf of the old, who do.
That is, arguably, fine, provided it continues to spread only among the young. The problem is, says Richard Grewelle from Stanford University, that if Europe looks across the Atlantic it will see that this does not happen.
“When public spaces re-opened in May and June, young adults were more likely to be seen socialising than older adults,” he said. This could be seen most clearly in Florida where, a bit after what would traditionally have been spring break, there was a sudden spike in cases among those in their early twenties.
It did not stay there for long. “These individuals came in contact with older relatives and friends, which has driven the subsequent increase in deaths [now up two to three times since the daily lows in June]. Similar features are probably true in some European countries,” he said. If he is correct, then we would expect to see first a shift in the population getting infected then, a fortnight later, a rise in deaths.
With coronavirus, however, there is always another theory. Dr Paul Tambyah, president-elect of the International Society of Infectious Diseases, said that an increasingly common mutation in the coronavirus may be making it less deadly. It is a truism of virology that viruses, which have no interest in killing their host, evolve to be increasingly benign. They fade into the background to the point where they become a “common cold”. Is this what we are seeing?
It’s not impossible but, other scientists said, it’s unlikely. Professor Brendan Wren, from the London School of Hygiene and Tropical Medicine, said: “It would be offering false hope to suppose it is weakening yet.” He did offer yet another explanation for why the disease’s apparent severity could be diminishing. It could be that what is key is not who it infects, but how.
“With hand hygiene and social distancing, the infectious dose would be lower,” he said. Instead of sitting next to someone on the bus and breathing in exhaled air for 15 minutes, we catch the virus as a glancing blow - and, like a glancing blow, can fight it off better.
As ever with the pandemic, simple questions have a complex answer - normally several. But if there is one lesson most virologists do agree on, it’s that countries have not yet gone wrong when they have prepared for the worst.
This is why Dr Pittard hopes that the idea the virus is weakening, or health services are getting stronger, does not take hold. “I wouldn’t want the public to be lulled into a false sense of security.”