OPINION | DR. MARC SIEGEL

Our leaders need to be transparent about their health, and we need to keep our masks up.

Among the nearly 60 Democratic members of the Texas House who traveled to Washington, D.C., last week to prevent the passage of a GOP election bill, so far six have tested positive for COVID-19. The first question that needs addressing is whether they were really vaccinated. I think they should show proof, as public confidence and believability is at stake, not to mention faith in the COVID-19 vaccines.

Second, how many people are testing positive among those they have been in contact with in Washington, D.C.? At least one White House aide and a staffer of House Speaker Nancy Pelosi have tested positive, but there might be more. So far the White House is not being completely transparent about this and the numbers matter.

What is the science? COVID-19 science is evolving, but currently 83% of the new isolates are the highly contagious delta variant (per the Centers for Disease Control and Prevention on Tuesday), which is crowding out the others. So it seems likely that these lawmakers are infected with it.

The CDC, Harvard and Johns Hopkins have all studied breakthrough infections (people who get infected despite the vaccine) and previously found the number to be approximately 1 in 10,000, but that was before the delta variant emerged in the U.S. And that is a number that applies to your risk during a usual day, walking down the street, going to work, etc.

When you look at the story with the Texas lawmakers, the more significant number is how protective two doses of a messenger RNA vaccine (if that’s what they had) are against coming in close, prolonged contact on an airplane without a mask on or in a crowd at the Capitol.

Two shots of the Pfizer/BioNTech vaccine, for example, have been found to be approximately 84% effective against the delta variant, which means that approximately 10 to 15 out of 100 people who are directly exposed to the delta variant will test positive after a few days, but most cases will be quite mild. (As per the CDC, over 97% of hospitalizations and deaths are among unvaccinated patients). The news about the Texas lawmakers seems to follow this model.

Is this a superspreader event? It depends on your definition, but I would say yes. It sounds like a term out of the movie Contagion, but what it means is that some people have a higher viral load initially than others. They are carrying more virus in their noses and are far more likely to spread it.

The vaccines have been shown to decrease this greatly, but not 100%, and it also depends on a person’s immune status. Plus, the delta variant has been shown to have a higher viral load initially than the others.

In fact, according to a recent study from China’s Centers for Disease Control, those people infected with the delta variant averaged 1,000 times more copies of the virus in their noses and respiratory tract than with the original COVID-19 that was in circulation last year.

What can we learn? One take-home message is that the current CDC rules that people must wear masks on planes and public transportation are wise and should remain in place. A study from the Department of Defense showed a significant impact of masks reducing viral transmission on planes.

The second lesson is that no one is impervious to this virus, especially with the delta variant around, though the Pfizer and Moderna two-shot regimens provide a great deal of protection. This story does not change that.

The most important lesson here is one of transparency and consistency. Perhaps the Texas lawmakers who are fleeing their state and its voting rights debate have not been completely open here or great role models regarding COVID. But the point is they should be.

Our leaders must follow their own guidelines if we are to take them seriously and sometimes, they need to prove it. The president and the Democrats in Congress should call them out on this. Deviation from public health guidance is a nonpartisan concern.

Dr. Marc Siegel, M.D., is a professor of medicine at New York University. He wrote this column for The Dallas Morning News.