On Monday the Director of the CDC urged Americans not to travel, claiming it exacerbates the spread of Covid-19. However she,

• Fails to explain how she thinks this happens
  
• Makes no distinction between those who have been vaccinated and those who haven’t been
  
• And offers an argument that is simply false to bolster her case

Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, reiterated during a White House COVID-19 briefing that Americans should limit travel.

Travel, she explained, only exacerbates the spread of COVID-19.

…”We have been consistently discouraging travel, saying, ‘Please keep it limited to only essential travel.'”

It’s literally true that someone infected with a virus can bring it to someplace else where the virus isn’t already spreading in the community via travel. But it isn’t true to say that travel is driving cases or hospitalization in the U.S. where the virus is already spreading broadly. And it isn’t correct to say, as she does, that travel is causing spikes.

First she offers that cases are rising somewhat again in the U.S. at the same time that travel is rising. That’s an overly simplistic view.

If correlation were causation what would we say about Texas which has its lowest level of cases in 9 months, and fewest hospitalizations in 6 months, three weeks after dropping its mask mandate and re-opening bars at 100%? Clearly something else is going on here. Cases have generally continued to decline in the southern half of the country, and grown in the northern half.

Credit: New York Times

The biggest increases are coming from places like New York, New Jersey, and Michigan. There’s not even a correlation with cases and mask mandates or business closures. Sure, Florida – one of the hottest aviation markets – has seen a small increase but it’s nothing compared to the Northeast.

There’s a plausible case this is a function of temperature and variants, but it’s hard to argue that it’s because of travel. Indeed the rate of decrease in Covid cases slowed before travel had picked up. But Walensky makes an even broader claim,

What we’re seeing now is more travel than we saw – than we saw throughout the pandemic, including the Christmas and New Year’s holidays,” she said.

She added that the country has seen a COVID case surge following every holiday since the pandemic’s onset. “I would just sort of reiterate the recommendations from CDC, saying please limit travel to essential travel for the time being.”

Walensky ties spikes in the virus with holiday travel. But that simply doesn’t match the data.

• Covid was already on the upswing prior to July 4th. In fact two weeks after that holiday cases began to decline.

• The low point after the summer case surge came following Labor Day.

• The ‘third wave’ of cases began in October, and – a dip in reporting over the Thanksgiving holiday while data slowed aside – there was no break in trend following Thanksgiving.

• Two weeks after Christmas we began to see a decline in cases from the top.

Credit for Graph of Cases to New York Times

When people gather for holidays in their home town they can spread the virus. When they travel they may see even fewer people than if they’d stayed home. Travel itself isn’t what’s risky. It’s what you do at your destination. That’s the guidance CDC should be offering – to avoid crowded, poorly-ventilated indoor spaces.

Travel doesn’t seem to be the driver, and holidays don’t either which you can clearly see in Italy and France (and France by the way has domestic travel restrictions in place in lockdown regions but that didn’t stop their surge).

Credit: Google

Credit: Google

In any case vaccinated people should be able to travel. The CDC’s own study finds that vaccinated people are neither at significant risk of contracting the virus nor are they a significant risk for spreading it. Young children may face even less risk than vaccinated adults.

Some people – including travelers – are acting like the pandemic is over. It’s not. That’s why it’s so important to get vaccinated as soon as possible. Risks will remain after that, but they should be manageable ones.

The CDC has done a tremendous amount to sully its reputation during the pandemic. A new director gives the agency a fresh start. She should be telling scientific truths and offering cogent explanations. As a way to try to make sense out of why the CDC would be telling even the vaccinated to stay home some have even tried to make arguments that it would be unfair to those who haven’t had a chance to get the shot yet. Otherwise, what is even the argument here?