Victorian Health authorities recommended residents resume wearing face masks indoors in July as ... [+] Covid-19 infections began to rise again across Australia. Here members of the public wore face masks as they waited to board a tram on July 14, 2022 in Melbourne, Australia. (Photo by Graham Denholm/Getty Images)

Remember the flu? That titan of a virus that caused 140,000 to 710,000 hospitalizations and 12,000 to 52,000 deaths each year from 2010 to 2020? Well, influenza activity was unusually low during the two years following the Spring of 2020 when that little thing called the Covid-19 pandemic began. That’s been the case for much of the world until this Spring 2022. That’s when Australia and other countries in the Southern Hemisphere began having earlier than usual flu seasons that have turned out to be quite bad. What’s going on Down Under doesn’t bode well for the U.S. and other countries in the Northern half of the very non-flat Earth for this coming Fall and Winter. And with the Covid-19 coronavirus being controlled in the U.S. about as well as bots on Facebook and Twitter, this raises “Twindemic” concerns. In this case, Twindemic has nothing to do with Mary-Kate and Ashley Olsen but represents the possibility that both Covid-19 and the flu will soon surge at the same time.

For what’s been going down Down Under, take a look at the Australian Influenza Surveillance Report and Activity Updates from the Australian government. The flu virus has been flat out like a lizard drinking to use some Aussie slang. As of August 14, there’s been 216,725 reports of laboratory-confirmed influenza cases to the National Notifiable Diseases Surveillance System (NNDSS) in Australia so far this year. Remember laboratory-confirmed cases probably represent only a fraction of total cases. After all, when you are sick with the flu, your first inclination may be to stay at home and watch Captain Underpants in your underpants rather than go to the doctor’s office. Plus, a decent fraction of people infected with the influenza virus don’t even know that they are carrying the virus and may in turn silently infect others, which would be the opposite of being sexy and knowing it.

The flu virus is naturally not something that you want to catch if you can avoid it. To know what it feels like to have the flu, just remove the “l” in the middle of the word. That’s what the flu virus can do to your body. While most people infected suffer several days of oh-I-feel-like-dog-doody, getting the flu can in some cases land you in the hospital, especially if you not vaccinated against it or are a child (meaning physically and not emotionally) or over 65 years of age. The NNDSS has recorded 273 influenza-associated deaths this year as well. Since April 2022, sentinel hospital sites have logged 1,666 flu-related hospital admissions with 6.4% being admitted directly to ICU. Admittedly, such number aren’t good. Keep in mind too that sentinel hospital sites represent only a fraction of all hospital sites in Australia.

Covid-19 precautions during the previous two Summers probably kept the flu virus at bay in ... [+] Australia. Here three girls wearing face masks sat above the Bradfield Highway in the suburb of North Sydney with the city in the background on July 07, 2021 in Sydney, Australia. (Photo by James D. Morgan/Getty Images)

This seems to have been a real A-list of a flu season for Australia with 82.3% of the laboratory-confirmed influenza cases having been due to influenza A. Labs didn’t further subtype these influenza viruses in 94.4% of the cases but 4.8% turned out to be influenza A(H3N2). Of course, a big question is whether the strains of the flu put in this year’s version of the flu vaccine are good matches for what strains have been circulating in the Southern Hemisphere and will be circulating in the Northern Hemisphere. It’s still too early to tell if this has been the case in Australia.

Since the world is not flat despite the claims of Kyrie Irving, Tila Tequila, and maybe one of your former school-mates, each calendar year a set of flu virus strains typically follow a bottoms-up pattern. They first spread in the Southern Hemisphere from April through September while it’s colder and drier down there. They they begin spreading in the Northern Hemisphere, starting in September, October, and November as the weather turns colder and drier up here. So in theory, if you wanted to enjoy the flu season close to year-round, you could bounce back and forth between the U.S. and Australia.

Why has the flu season been unusually mild for the two Winters since the Covid-19 pandemic began? Gee, let’s take a wild guess. Could it have been magic? Probably not. How about ivermectin? Umm, there’s no scientific evidence that ivermectin is effective against the flu or Covid-19. Bernie Sanders’ mittens? No, there haven’t been enough to go around. Mark Zuckerberg riding on a hoverboard while waving an American flag? Uhh, no. Hmm, how about all the Covid-19 precautions that people used to do like face mask wearing and social distancing? Yes, these are the same precautions that some people, politicians, and anonymous social media accounts have been claiming don’t work against the spread of respiratory viruses. If wearing face masks supposedly don’t work, then how come the U.S. Centers for Disease Control and Prevention (CDC) found that “In terms of hospitalizations, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations in the 2020-2021 season was the lowest recorded since this type of data collection began in 2005.” Chances are wearing face masks, social distancing, reduced travel, and other Covid-19 precautions helped keep the flu at bay for the previous two Winters. That’s probably “Twindemic” concerns over the two Winters following the start of the Covid-19 pandemic didn’t materialize.

Ah, but this Winter may be a different story. Recently, people have been ditching face masks as if they were soiled underwear. There are concerns that the CDC’s recent relaxation of Covid-19 precautions such as effectively eliminating the recommendation of quarantining after being exposed to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be yet another example of premature relaxation. In fact, many on Twitter suggested that this is a sign of the CDC “giving up” on trying to combat the Covid-19 pandemic, as I covered for Forbes. Over the previous two years, each major relaxation of precautions was soon followed by a Covid-19 surge. First the Delta variant-fueled surge in the Summer of 2021 came after the CDC relaxed face mask requirements. Then the Omicron variant-fueled surge in the Winter 2021-2022 happened after most travel restrictions were lifted. Most recently, there’s been the Spring and Summer 2022 surge that’s still going on after most face mask requirements were lifted. All of this sounds a bit cause-and-effecty, doesn’t it? So what could happen this coming Fall and Winter with little-to-no precautions being in place and the flu season been already bad in the Southern Hemisphere? The answer may rhyme with “twindemic.”

Flu shots aren't yet available but you should consider getting one when they are. (Photo by Noam ... [+] Galai/Getty Images)

Clearly, getting infected with the SARS-CoV-2 and the flu virus at the same time would not be good. Your immune system is not like Jackie Chan in a bar fight, saying, “bring it on” to everyone. When it’s busy fighting one virus, your immune system may have less resources to fight another virus, which may lead to even worse health outcomes. Plus, there’s the whole limited health care system capacity thing. Having the health care system fill up with both Covid-19 patients and flu patients could push things beyond capacity. And where have you heard of that potential problem before? Could 2022 be a bit like 2020 too? Moreover, you may have people thinking that they have Covid-19 and taking Paxlovid and other more Covid-19-related treatments when they actually have the flu.

Therefore, preparing the public for both another possible Covid-19 surge as well as a potentially bad flu season will be important. This includes encouraging and facilitating more face mask use and getting people vaccinated against both the flu and Covid-19. If the U.S., state, and local governments don’t prepare for a possible Twindemic, things could get a little confusing and chaotic, which hasn’t happened to the U.S. in responding to an outbreak or epidemic before, right?