Lockdowns, masks, and distancing are saving lives in more ways than one: in the southern hemisphere winter, the spread of flu is at remarkably low levels.

“I think if we could get this sort of effect every year, we’d be very happy,” said Professor Ian Barr, deputy director of the World Health Organization Collaborating Centre for Reference and Research on Influenza.

Influenza is hard to combat, but it almost disappeared

It’s one of the fears we’ve had with COVID-19 from the start: when winter comes and we add the pandemic to the higher winter health burden, it will be a disaster. But as it turns out, we get a 2-for-1 offer with the coronavirus restrictions.

It’s wintertime in the southern hemisphere, and it’s exactly the time when the flu starts to flare up.

The flu is a nuisance to most people, but it’s also a very threatening disease in its own right. In the severe flu season 2017-2018, health officials estimate that 900,000 Americans were hospitalized, and on average, the flu kills 30,000 people in the US every year. Worldwide, it’s estimated that the flu kills over 600,000 people every year — while not as severe as COVID-19, the flu is no laughing matter.

Luckily, it turns out that the measures aimed at containing and halting the spread of COVID-19 also help with the flu.

We’re seeing this already in several countries. Australian Medical Association NSW vice-president Andrew Zuschmann said this year doctors are already seeing much lower transmission rates of influenza than in previous years.

“What it’s telling us is that many of the measures that are working to contain the spread of COVID-19 within the community are also very effective at reducing transmission of influenza,” he said.

All across the Southern hemisphere, officials were bracing for a wave of flu on top of the ravaging coronavirus — but the wave of flu never came. In the latter half of June, Australia registered only 85 lab-confirmed influenza cases — compared to 22,047 for the same period in 2019. In Chile, Cases have dropped to 1,100 this season, compared to 210,000 last year. In Argentina, cases have also decreased from over 4 million to 151,000.

Speaking with the Wall Street Journal, Chilean infectious-disease specialist Claudia Cortés says the flu has almost disappeared.

“We keep checking for the other viruses, but all we’re seeing is Covid,” said Dr. Cortés, the Chilean doctor. Of roughly 1,300 Covid-19 patients she has treated since late March, only a handful had the flu. “We were surprised by the decline in the other viruses like influenza. We never dreamed it would practically disappear,” she said.

Similar things are being reported all across the southern hemisphere: even during peak flu season, the numbers are still very low.

Now we know how to combat influenza

The decline is good news for health officials all around the planet, especially when winter also comes in the northern hemisphere.

This improvement is largely attributed to protective measures against COVID-19. Whether it’s face masks, distancing, or things being shut down, everything that reduces COVID-19 transmission also helps with the flu.

Kids are also an important transmission route for the flu. As many countries closed down schools, this also helped with the flu.

While this is all encouraging, there’s also a concerning takeaway. This all seems to suggest that flu and COVID-19 move in tandem, but even as the flu has all but disappeared from South America, COVID-19 is soaring. This suggests that the novel coronavirus is much more contagious than the flu viruses, and even as the flu is tamed in wintertime, dealing with COVID-19 is an entirely different problem.

The northern hemisphere is not doing a great job with the pandemic in the summertime. Cases are surging across the US and parts of Asia, and even parts of Europe which seemed to have things under control a few weeks ago, are reporting concerning developments.

The flu situation is good news, and it offers a glimmer of hope for wintertime — but there’s still a long way to go to wintertime.