Mr. President, international COVID rules for travelers are primed to fail

President Biden signed an executive order mandating new international COVID rules for travelers entering the US, including citizens. That’s a potential problem.

COVID-19 testingOn January 21, newly sworn-in President Joe Biden signed an “Executive Order on Promoting COVID-19 Safety in Domestic and International Travel.” With the world quickly approaching 100 million COVID cases with 2.2 million deaths, the US needs comprehensive international COVID rules. They will prevent many new domestic COVID cases and as many as possible from coming into the US through international visitors and returning citizens.

The executive order seeks to mandate masks for traveling by planes and other public transportation, and it develops new public health measures for domestic travel. It seeks to address international travel by imposing meaningful international COVID rules. Testing and quarantine requirements will apply to international travelers, including US citizens. The president has also directed that guidelines must include US border entry by land and sea. The directive will also include rules that address COVID-19 vaccination.

The Biden Administration’s COVID plans for travelers start with the Centers for Disease Control and Prevention (CDC). That’s a serious problem. CDC recommendations don’t appear to follow quality science, at this time. For example, the recommendations merely requires a “viral” COVID test. So, it includes molecular tests such as PCR, as well as the far less accurate Antigen tests. In addition, the CDC timing for testing and quarantine recommendations are ineffective.

Some testing methods produce higher false-negative rates than others. They are not suitable for screening travelers.

COVID tests’ false negative rates are critical in determining effectively screening travelers. For example, if the false-negative rate of a COVID test is 20 percent, that would mean that for every ten travelers who test negative, it’s likely that two are infected, or 200 out of every 1,000.

Get refunds in cash when airlines cancel your flightPCR, a molecular test method, looks for traces of the virus’ genetic material in samples taken from noses and throats. The CDC considers PCR testing to be the “gold standard.” It has the lowest false-negative rate of all current tests for COVID. Another molecular test for COVID is LAMP. It can be run much more quickly than PCR. So far, tests have shown it has great promise. But the test as a means to regulate international border entry needs more study, according to many scientists.

Antigen tests look for proteins that live on the virus’s surface. They take much less time than PCR and even LAMP to obtain test results, sometimes only minutes. While Antigen testing is very fast, it’s less accurate than PCR. It has a potential false-negative rate significantly higher than either PCR or LAMP.

Another serious problem is that the current CDC recommendation is for either molecular or antigen testing 24–72 hours before departure to the US. If a traveler is tested three days before departure, that gives them three days to become infected before leaving.

The timing of COVID-19 infection is crucial to obtaining usable results.

The American College of Physicians’ Annals of Internal Medicine (AIM), a study of false-negative rates of PCR COVID testing was published in August 2020. The purpose of the study was to “estimate the false-negative rate by day since infection.” The study estimated that during the four days of infection prior to symptoms occurring, typically the fifth day, the probability of getting a false negative test result ranged from 100 percent on day 1 to a mean of 67 percent on day 4. Even on day 5, when most people infected with COVID begin to exhibit symptoms, the mean false-negative rate is still 38 percent. It doesn’t drop to 20 percent until the eighth day. Even PCR testing is essentially worthless in determining if a person is infected with COVID in the first days after an infection occurs.

An isolation/quarantine requirement can make up for testing shortcomings if it’s long enough and testing is properly timed.

The CDC currently recommends that after arrival in the US, travelers should self isolate/quarantine, then get tested 3–5 days later. If they test negative, they can end quarantine after seven days. Without testing in the US after arrival, they recommend self-isolate/quarantine for 10 days. The Biden Administration plans to turn quarantine and testing recommendations into requirements.

The timing of mandated testing while travelers are in quarantine is important. If a traveler became infected the day before returning to the US, and are tested on the third day after arrival, that’s day 4 of the infection. A PCR test has a mean false-negative rate of 67 percent that day. A day later that drops to 38 percent. At that rate, a negative result is close to meaningless.

The Biden Administration should institute requirements to keep the US as safe as reasonably possible, without making international travel impossible.

I recommend that the Biden Administration seriously consider the following requirements for international visitors and US citizens returning to the US:

1. All travelers should be required to have a negative result from a molecular test for COVID (PCR or LAMP, once LAMP is determined to be acceptable) from 24–48 hours prior to departure for the U.S. Antigen testing shouldn’t be accepted.

2. All travelers should be required to self-isolate/quarantine upon arrival. They should be required to be tested with a molecular test 5–7 days later. Upon a negative test, they can leave isolation/quarantine once seven days has elapsed.

3. If they test positive, they must remain in isolation/quarantine and follow CDC guidelines.

In addition to the above regulations, the Biden Administration should develop protocols for international travelers who have been vaccinated, including difficult-to-forge documentation.