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Mar 05, 2025

COVID-19 pandemic, what we got wrong, how science evolved since

In early 2020, scientists raced to understand COVID-19, trying their best to provide timely and accurate information to the public. As knowledge grew, experts revised their guidance on seemingly

In early 2020, scientists raced to understand COVID-19, trying their best to provide timely and accurate information to the public.

As knowledge grew, experts revised their guidance on seemingly everything about the virus, including how it spread, whom it affected, how to stay safe, and how the pandemic would eventually come to an end.

To some, those changes read like flip-flops and contributed to a sharp decline in Americans’ trust in science.

But revisions like those are normal, experts said.

“This was a completely new disease,” said Dr. Daniel Kuritzkes, chief of infectious diseases at Brigham and Women’s Hospital.

Scientists based their initial recommendations on COVID-19’s similarities to other viruses. And they prioritized saving lives, preventing hospitals from being overwhelmed and preserving protective equipment for essential workers.

Scientists did, however, miss an opportunity to educate the public about uncertainty and to admit they could be wrong, Kuritzkes said.

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We talked with infectious disease experts about early misconceptions about COVID-19 and how our understanding of the disease evolved from early 2020 until today.

MISCONCEPTION: COVID poses a low risk to the general public

Though scientists said early on the risk of COVID was low for average Americans, that changed as more information became available.

In the early months of the pandemic, scientists assumed COVID would behave like other coronaviruses and mainly spread through close, prolonged contact. As studies emerged showing COVID was mainly transmitted through aerosols, guidance changed and the risk to Americans was understood as higher.

“Science advances by incorporating new information as it emerges, resulting in changes to recommendations,” said Kuritzkes.

That doesn’t mean people should be skeptical of scientists, but aware that information — and diseases — can evolve. For example, while the bird flu currently poses a low risk for humans because it hasn’t spread from person-to-person, experts said the risk could change as time goes on and the virus acquires new mutations.

MISCONCEPTION: COVID is not airborne

Dr. Peter Hotez of Houston’s Baylor College of Medicine said global scientists initially declaring that COVID was not airborne was the “single biggest mistake that was made.”

In March 2020, the World Health Organization posted on Twitter, now known as X: “FACT: #COVID19 is NOT airborne,” adding that virus particles are “too heavy” to hang in the air. Later, studies showed aerosols from infected people can be suspended in the air long enough to infect others, especially with poor ventilation in indoor spaces.

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FACT: #COVID19 is NOT airborne. The #coronavirus is mainly transmitted through droplets generated when an infected person coughs, sneezes or speaks.To protect yourself:-keep 1m distance from others-disinfect surfaces frequently-wash/rub your 👐-avoid touching your 👀👃👄 pic.twitter.com/fpkcpHAJx7

Experts said early recommendations about the virus were based on other coronaviruses, not the one that causes COVID-19.

“There’s not many true airborne respiratory viruses that are transmitted [like COVID],” Hotez said.

WHO didn’t recognize the virus as airborne until late 2021.

Misconception: You need to wash packages and groceries

Initial belief that COVID mainly spread through close contact with large droplets led many to wash and disinfect anything that came in from outside, including packages and food, a practice Hotez called “pretty much a waste of time.”

In a YouTube video from March 2020 that went viral, Dr. Jeffrey VanWingen, a family physician in Grand Rapids, Mich., advised viewers to wash fruit in soapy water for 20 seconds “like we should be washing our hands.”

Reflecting back on the video now, VanWingen said his advice came at a time when officials were working to “flatten the curve” and operating with “aggressive caution as things became more clear.”

“This was the first big pandemic that many of us in the healthcare field had to struggle through,” he wrote in an email to the Globe. “Science was happening in real time at a fast pace as we worked to understand the virus and its impact.”

While some COVID transmission could be linked to droplets, it turned out that this was a “minor mode of transmission” compared to aerosol spread, according to Kuritzkes.

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MISCONCEPTION: People don’t need to wear masks

Partial knowledge of how COVID spread was also linked to early guidance urging the public to not wear masks and reserve that measure for healthcare workers and others who had close contact with those who had COVID.

The recommendation went viral with a February 2020 Tweet from then-Surgeon General Jerome Adams, who wrote, “Seriously people — STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus, but if health care providers can’t get them to care for sick patients, it puts them and our communities at risk!”

Public health officials largely started recommending masking for everyone in early April 2020. Still, officials said earlier masking recommendations could have had a “pretty profound impact” on the virus’ spread.

“If there had been guidance and widespread adoption of masking early on, it is possible that many fewer people might have become infected,” Kuritzkes said. He added that an earlier appreciation of the ability of masks to prevent COVID could have also limited some of the widespread closures of businesses.

MISCONCEPTION: Vaccines will take years to create

COVID-19 vaccines — which were first rolled out in December 2020 — were developed faster than any vaccines in history. Before that, the speediest vaccines created were for the mumps, which took four years.

The speed at which the COVID vaccine was developed has been a central concern for people hesitant about getting it.

In reality, the reason for the shortened timeline was that mRNA vaccines had been in the works for years before COVID erupted. “We were extraordinarily lucky, and we’re lucky that there had been a substantial investment in basic vaccine technology,” Kuritzkes said.

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In 2023, two scientists were awarded the Nobel Prize for their discoveries — made between the early 1990s and early 2010s — that contributed to the development of mRNA vaccines against COVID.

MISCONCEPTION: The pandemic will end when we reach herd immunity

Herd immunity, or indirect protection from an infectious disease that happens when enough of a population has previously been infected or vaccinated, was a hot topic at the start of the pandemic, especially among the public, which was itching to resume normal life. Experts said society would need to achieve about 70 percent to 80 percent immunity rates to reach the coveted metric.

Now, experts agree society never reached “herd immunity” as it was thought of initially. That’s because vaccines and previous infections did not stop the virus from spreading, as initially believed.

Vaccine makers also had trouble creating updated shots quickly enough to keep pace with the virus’s evolution.

Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said vaccines provide “incredible protection” against the virus in the first two months. But as immunity starts to fade, people become susceptible to COVID once again.

“What wasn’t understood was the concept of waning immunity that we saw with other coronavirus vaccines,” he said.

Vaccines did, however, make COVID-19 far less severe and allowed many of us to put the pandemic behind us.

Emily Spatz can be reached at [email protected]. Follow her on X @emilymspatz.