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Experts discuss the falsehoods and half-baked ideas that are in circulation about COVID-19 transmission, treatment and equivalence to the flu.
As SARS-CoV-2 virus that causes COVID-19 spread around the world, misinformation about the RNA virus and the disease it causes were fellow travelers.
Every public health crisis spawns some falsehoods and unsubstantiated beliefs, but the COVID-19 pandemic has engendered more than its fair share, partly because of the dynamics of social media and partly because it is a new disease. Research published in the American Journal of Tropical Medicine and Hygiene this summer identified 2,311 reports of rumors, stigma, and conspiracy languages in 87 countries.
MJH Life Sciences™’s, the parent company of Managed Healthcare Executive®, recently hosted a one-hour free webinar about COVID-19 myths as part of its COVID-19 Coalition.
Saskia Popescu, Ph.D., M.P.H., M.A., CIC, term assistant professor, George Mason University, and adjunct professor, University of Arizona College of Public Health, moderated the discussion that included Angela Rasmussen, Ph.D., associate research scientist, Columbia University Mailman School of Public Health, and Emily Ricotta, Ph.D., M.S., research fellow, Epidemiology Unit, Division of Intramural Research, of the National Institute of Allergy and Infectious Diseases.
The “airborneness” of SARS-CoV-2 and its transmission continues to be a source of confusion. Just yesterday, CDC issued a revised guidance that says SARS-CoV-2 can linger in the air in smaller particles and spread among people who are more than six feet apart while also stating that the virus is most frequently spread through relatively large respiratory droplets among people in close contact with one another.
During the webinar, which was held before CDC issued its guidance, Rasmussen noted that there is a limit to just how “airborne” SARS-CoV-2 is. For instance, the virus is not moving through the air ducts of a building and travelling long distances to infect people in other rooms or on other floors. “This virus does not appear to be particularly transmissible in that way,” Rasmussen said.
“It's not like measles — it's not like you're gonna walk inside and automatically get COVID,” said Ricotta.
But the word “airborne” could mean different things to different people, and it may not be clearly understood, noted Ricotta “We, as scientists, need to be maybe a little clearer in the way that we're communicating this to everybody,” she said. “And I think that's where some of the confusion has come in.”
Without a vaccine, natural infection is the only way to achieve herd immunity. But achieving herd immunity through transmission and natural infection would put a lot of people at risk, noted Ricotta. Currently, roughly a quarter of the population has been infected, but the threshold for achieving herd immunity is between 40% and 70%.
“Globally, we've never managed to achieve herd immunity through natural infection for any pathogen,” Rasmussen noted. Some local populations have gained herd immunity; for instance, it is believed that herd immunity in the Americas has kept the Zika virus from circulating. “However, that doesn't provide long-lasting immunity that will keep it out of the global population indefinitely.”
The panelists said that data, especially data on a new pathogen, are tricky and tell a story that requires interpretation. In order to see the full story, people can’t look at just one data point, Ricotta explained. Data may show that 3,000 people were hospitalized, but it doesn’t put it in to the context of whether those 3,000 people were in a town of 5,000 or a city of a few million. Data quality is affected by a number of factors, such as the source and the consistency of data reporting.
The panelists also discussed models that were in the news this spring and how they might have contributed to some of confusion about the reliability of data.
Also I think the whole model thing has fallen by the wayside now that the country has experienced the pandemic for the better part of a year. Brix was big on models and she has also fallen out of the news
Models aren’t crystal balls that predict the future, Rasmussen said. They change and update as new data becomes available.
“So, people just need to understand models in the context of what they are,” she said. “They're not a roadmap to a certain future. They're an indication of what might happen if certain conditions are met.”
Are individuals truly asymptomatic or are they actually presymptomatic? It can be difficult to distinguish, explained Rasmussen. People who test positive without having any symptoms might be considered asymptomatic, but they could develop symptoms later. What’s more, asymptomatic cases are often based on self-reported data, but COVID-19 produces a wide, varied range of symptoms. Some people might not recognize their diarrhea might be a symptom of COVID-19, even though they didn’t have the telltale cough.
We do know that there is “a substantial amount of transmission from presymptomatic people,” Rasmussen said, and controlling the spread of COVID-19 remains difficult because people are infectious before they develop symptoms.
“So while asymptomatic transmission or asymptomatic cases and transmission probably exists, we don't really know the number for that,” she said. “But we definitely know that presymptomatic transmission exists, and it's a major driver of this pandemic.”
With more than 160 candidates in the pipeline, at least one of them will likely have an acceptable safety profile, but it isn’t possible to know what the safety of any of these vaccines will be without the results of the ongoing clinical trials, Rasmussen said.
The clinical trials of the vaccines are designed to provide data on their safety, but Ricotta also mentioned postmarket evaluations once the vaccine is approved to determine long-term safety and efficacy.
Every vaccine confers a little bit of risk, she pointed out. The flu vaccine may hurt your arm, make you tired, or even give you a little fever, and all these side effects are considered “acceptable risks” compared with getting the actual disease. So far, it seems vaccines for COVID-19 are relatively safe, and it will make sense to get the vaccine “because we know that COVID itself is very, very bad,” Ricotta said.
The myth of youthful immunity to SARS-CoV-2 is one that can be decisively debunked: “Young adults and children can absolutely get sick from COVID,” said Ricotta. She noted that the CDC reported that the number of cases in people under the age of 20 doubled from March to August. The data show a clear shift in the pandemic in the U.S. from older individuals to younger ones.
However, it is true that young people, as a group, tend to have milder symptoms, a pattern that may explain the confusion about whether young people are immune from infection. Importantly, Ricotta, added, not only can younger people get sick from COVID-19, but they are but younger people can definitely still transmit COVID-19.
The evidence does not currently show that hydroxychloroquine, either by itself or in combination with another treatment, has any measurable clinical benefit in COVID-19, Rasmussen said. In June, the FDA revoked its emergency use authorization for hydroxychloroquine and chloroquine.
The only people who might view hydroxychloroquine as a miracle drug as those who take it for lupus, rheumatoid arthritis, or malaria, she noted.
President Trump posted remarks today that made comparisons between COVID-19 and the flu. In a Tweet that Twitter has flagged as spreading misleading information, the president wrote, “Flu season is coming up! Many people every year, sometimes over 100,000, and despite the Vaccine, die from the Flu. Are we going to close down our Country? No, we have learned to live with it, just like we are learning to live with Covid, in most populations far less lethal!!”
During the webinar, Ricotta said that as COVID-19 first began to spread in China, the Northern Hemisphere was still in flu season and there were concerns that people were not getting their flu vaccine. This timing might explain why the narrative began to emerge that COVID-19 was no worse than the flu, she said.
However, as the understanding of SARS-CoV-2 improved and the pandemic spread to North America, the difference became more apparent. Flu and COVID-19 have different, if overlapping symptoms, and the mortality rate is higher for COVID-19, Ricotta noted. “Comparing the flu to COVID is sort of an unfair comparison.”
Differentiating COVID-19 from the flu is important as the U.S. and the rest of North America enters another flu season. They might both be respiratory viruses, but they are “fundamentally different viruses…from a virology perspective,” Rasmussen said.
“It is important to know that if you get COVID, you won't be immune to flu; if you get a flu shot, you won't be protected against COVID,” she said. “But you should still get your flu shot. And you should still take the same precautions to avoid getting infected with either because both of them can be severe public health problems.”