Experts weigh in on what we know and don’t know about the delta variant and vaccines from Crain’s Detroit

August 30, 2021

By Dustin Walsh from Crain’s Detroit

The COVID-19 pandemic has always been filled with difficult questions and assumptions. The data is never perfect and the numerous headlines are confusing.

With the rise of the delta variant of the coronavirus across most of the U.S., we’ve entered a messier phase of this 17-month nightmare. Much of the media coverage focuses on new cases and outbreaks, even among the vaccinated. Vaccine naysayers often draw incomplete results using data they don’t always understand. Politicians, parents and school boards are battling over whether masks should be mandated in schools. Meanwhile, hospitals in the southern part of the country are overrun — Florida has nearly twice has many people hospitalized with COVID-19 than in any previous surge.

Breakthrough infections. VAERS. Science. Everyone is limping along, looking for answers.

Crain’s turned to three local infectious disease experts to discuss the confusion and what is known and not known about the current surge.


Known: Vaccines reduce hospitalization and death

In Michigan through July, fewer than 0.16 percent of those vaccinated had experienced a breakthrough coronavirus infection and fewer than 0.01 percent of those vaccinated have been hospitalized with COVID, according to a Kaiser Family Foundation study. Throughout the summer, fewer than 5 percent of those hospitalized with COVID across the entire U.S. are fully vaccinated, according to U.S. Centers for Disease Control and Prevention data.

Joshua Petrie, a research assistant professor in the department of epidemiology at the University of Michigan School of Public Health, noted that infections are rising among the vaccinated, but those cases appear to be less problematic.

“(Vaccines) are very effective in reducing these severe outcomes,” Petrie told Crain’s. “Even currently where we are seeing signs that mild infections may be increasing among the vaccinated, the vaccines are still highly effective at reducing severe outcomes. A study was just published, that the University of Michigan contributed to, reporting that the vaccines reduced risk of hospitalization by 86 percent.”


Unknown: The number of people infected with COVID-19

Some reports state more than 100 million people in the U.S. have been infected with the coronavirus. But we really have no solid idea, particularly with nearly 170 million vaccinated in the country. Many of those vaccinated won’t even know they have the virus and therefore never get a test.

“The disease is diagnosed only when the infection causes symptoms such as fever and cough; a significant proportion of people who become infected never develop symptoms,” said Dr. Teena Chopra, chief of infectious diseases at Wayne State University School of Medicine. “Therefore, it is difficult to accurately quantitate how many people have been affected by the virus. Although vaccines provide a strong defense against severe illness caused by COVID-19, none fully protects against the infection, meaning many vaccinated people are still at risk of catching the virus and of transmitting it to other people.”

The CDC estimates about 28 percent of the Michigan population, or more than 2.8 million people, have been infected with the coronavirus.


Unknown: Whether Michigan will see a massive surge like in the South

The delta variant is here, but it’s not plaguing Michigan hospitals … yet.

“I think this reflects a combination of our recent local ‘surge’ in April, May and June, where we had a lot of cases … which brings with it a lot of innate immunity post-infection and our overall higher vaccination rate than those states experiencing widespread community transmission,” said Dr. Phillip Levy, assistant professor of emergency medicine, vice president of research and head of Wayne State University’s COVID-19 response team. “In Michigan we have many communities where vaccination rates are 75 percent or greater which gives me a sense of optimism that, even if we see outbreaks in the future, the impact will be lessened and people will not suffer significant consequences.”

Petrie, however, believes Michigan could see outbreaks like in the South when K-12 schools reopen this month and next as many are not requiring mask wearing.

“Michigan may be lagging behind some of the southern states because we have relatively higher vaccination and school has not started yet,” Petrie said. “However, Michigan is certainly at risk of seeing high case numbers like in those southern states, particularly as schools reopen in the fall.”

However, recorded deaths should be lower, Levy said.

“While we continue to see deaths across the U.S. from COVID-19, the case fatality rate is lower overall with this phase of the pandemic,” Levy said. “That is largely because the highest risk groups are very highly vaccinated. So I do not think we will see the dramatic spike in deaths that we witnessed in April 2020 here. We will continue to see people die from COVID-19, virtually all of them occurring amongst the unvaccinated.”


Known: Children under 12 will be authorized for the vaccine

All three experts emphasized the importance of the U.S. Food and Drug Administration’s approval of the COVID vaccines for children under 12 years old, who are not yet eligible to receive a vaccine.

The agency is expected to authorize a vaccine in the next few months, but a specific date is not yet known.

“There has been urgency to get trials done, which are needed to show safety. There is cautious optimism for EUA (emergency use authorization) of the Pfizer vaccine for ages 5-11 in the next few weeks,” Levy said.

Moderna is also running large pediatric trials to study the effectiveness and safety of using its COVID-19 vaccine for children under 12. Johnson & Johnson reportedly plans to begin a study of its vaccine in children as young as 12 years old in the fall.

“I hope that once this (EUA) occurs, parents will see the importance of getting their children vaccinated. The path to eradication of SARS-CoV2 is much easier if this group gets vaccinated.”

Chopra said the hold-up is the FDA’s asking of four to six months of safety data for children instead of two months’ worth for adults. Nearly all reactions and injuries from vaccines, not just the COVID-19 vaccine, occur within the first 45 days of administering.


Unknown: Will we need boosters forever?

The Biden Administration authorized a third vaccine booster shot, available to all Americans starting Sept. 20. Early research seems to indicate the vaccines’ effectiveness begins to wane after six months, but there’s not enough long-term data on whether boosters will be permanent.

“Confusion abound, but people need to keep in mind that we have never faced a pandemic like this before and the science is accumulating as we go,” Levy said. “Boosters will do two things: They will ‘recharge’ antibody production, thus bringing a period of immediate protection against infection, which will help reduce transmission, and strengthen your cellular (T cell) immune response, helping to ensure that once the antibodies go away you retain robust immunity to the virus.”

Petrie said mutations are also a factor.

“Although the unvaccinated are still much more likely to be infected, we are seeing that infections among the vaccinated do seem to be increasing.,” Petrie said. “This may be because either the virus changes enough to escape immunity from the vaccine or because that immunity decreases over time. Both of these factors may be at play. Boosters could help to keep immunity high, particularly in the highest-risk groups.”

Read, “Experts weigh in on what we know and don’t know about the delta variant and vaccines” from Crain’s Detroit

Experts weigh in on what we know and don’t know about the delta variant and vaccines from Crain’s Detroit
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