Coronavirus weekly need-to-know: Natural immunity, long-COVID, reinfection & more

Each week, we offer you a round-up of our noteworthy coronavirus coverage.

More than 33.5 million people in the United States have tested positive for the coronavirus as of Friday morning, June 18, according to Johns Hopkins University. That includes more than 600,000 people who have died nationwide.

Globally, there have been more than 177.2 million confirmed cases of the highly infectious virus, with more than 3.8 million reported deaths.

More than 147.7 million Americans are fully vaccinated against COVID-19 as of June 17 — about 45% of the total population, a Centers for Disease Control and Prevention tracker shows. About 55% of adults and 52% of people aged 12 and older are fully vaccinated in the U.S.

Here’s what happened between June 11 and June 17.

‘Delta’ likely to become dominant coronavirus variant in U.S.

The “Delta” coronavirus variant first discovered in India is raising some concerns in the U.S. as the number of infections caused by it doubles every week, according to former U.S. Food and Drug Administration commissioner Dr. Scott Gottlieb.

Gottlieb told CBS News’ “Face the Nation” that Delta is “probably” going to become the dominant coronavirus strain in the U.S., making up about 10% of current infections and posing greater risks to communities with low vaccination rates.

Emerging evidence from other countries, particularly the U.K. where it has become the dominant variant, shows Delta is more contagious, increases disease severity such as risks of hospitalization and is associated with a “modest” decrease in antibody activity in previously infected and vaccinated people compared to the Alpha variant, which first emerged from the U.K.

‘Delta’ likely to become dominant coronavirus variant in U.S., former FDA official said

Is it better to get immunity from catching COVID-19 — or vaccines?

Research shows both coronavirus infection and vaccination offers immunity that can protect people from getting sick again. But by how much and for how long remains unclear — a scientific gap that only time could fill.

Regardless of how immunity is acquired, there’s no telling whose bodies will or won’t create effective antibodies, and why they last longer for some than others; doctors speculate age or certain medical conditions might play a role.

Here’s what the latest data show about immunity from prior infection and vaccines.

Is it better to get immunity from catching COVID — or vaccines? What science shows

COVID-19 found in five states weeks before first cases were reported

A study of more than 24,000 stored blood samples representing all 50 states offers evidence that the coronavirus was in five states weeks before the first cases were reported there. Some of the infections were present before the first confirmed case in the country was reported.

The first positive samples came from people in Illinois on Jan. 7, 2020 and in Massachusetts on Jan. 8, 2020. The others were found in Wisconsin (Feb. 3), Pennsylvania (Feb. 15) and Mississippi (March 6).

The specific antibodies discovered in the blood samples, don’t appear until about two weeks after a person has been infected, suggesting the coronavirus was present in the U.S. as early as late December.

COVID found in five states weeks before first cases were reported, study says

Reinfection is rare — but not everyone has the same risk

A review of more than 9,000 electronic medical records of people who had severe COVID-19 in the U.S. found that less than 1% (63 people) contracted the disease again within an average of 3.5 months after first testing positive. The finding suggests a serious first round of the illness may protect you from a second terrible one.

But people with asthma or a nicotine dependence faced a nearly two and three times higher risk of COVID-19 reinfection, respectively. What’s more, nonwhite patients, particularly Black and Hispanic people, were about two times more likely to be reinfected.

Here’s why.

COVID reinfection is rare — but not everyone has the same risk, study finds

Symptom-free COVID-19 patients could still become long haulers

A study of nearly 2 million coronavirus patients across the country found that about a quarter developed at least one long-COVID symptom such as “brain fog,” breathing difficulties or high cholesterol 30 days or more after initially testing positive.

However, 19% who never felt sick during their infection later became a long-hauler, as those who go on to experience persistent symptoms for more than four weeks after diagnosis have come to be called.

As for risks of death among long-haulers, the odds were 46 times higher for people who were hospitalized and later discharged than those who were never admitted.

Symptom-free COVID patients could still become long haulers, study shows

Poll: Should COVID-19 vaccines be required for school?

A majority of Americans support requiring students to get vaccinated against COVID-19 before returning to school, a recent poll found.

A Gallup survey found that 61% of Americans polled support requiring college students to be vaccinated, 56% support requiring high school students and 51% support requiring middle school students to get a COVID-19 shot.

Respondents who have been vaccinated are more likely to support requiring students to get a shot compared to those who don’t plan to get a shot.

Should COVID vaccines be required for school? Here’s what Americans said in poll