COVID-19 vaccines were never promised to be 100% effective and experts are united in saying they remain the best way to fight the pandemic.
But a growing number of advanced cases (the term used to describe people who become infected with the coronavirus despite being completely vaccinated) call attention to what research is still needed to better understand the virus.
This past week, advanced infections were put in the spotlight as more people across the nation, fully vaccinated and high-profile, including Chattanooga Mayor Tim Kelly, announced that they had tested positive for COVID-19. Kelly, 54, tweeted Wednesday that she had “mild allergy-like symptoms” thanks to the vaccine that prevented a more serious case.
“We knew we were going to see these advanced infections, but the important thing is to look at what happens to these people,” said Dr. Jensen Hyde, a hospitalist at Erlanger Medical Center who also has a master’s degree in public health. “We have people who have advanced infections who have a very, very high risk of hospitalization and death, and they can now smell or be asymptomatic.”
According to the Johns Hopkins Bloomberg School of Public Health, there is a difference between “advanced infections” that occur when a fully vaccinated person tests positive for coronavirus and “advanced disease” that occurs when a fully vaccinated person experiences symptoms of coronavirus. COVID. 19.
This distinction is important when discussing the effectiveness of vaccines, as Johnson & Johnson is currently the only pharmaceutical company with a COVID-19 vaccine available in the United States that uses a positive test result plus the presence of a symptom as a criterion for evaluating vaccine efficacy. . Both trials for the Pfizer and Moderna vaccines, which were 95% effective against the original coronavirus variant, studied whether vaccines prevented COVID-19 symptoms and not infection.
Despite the growing prevalence of vaccinated people who test positive for coronavirus, the vast majority of hospitalizations and deaths from COVID-19 remain unvaccinated, a strong sign that vaccines are doing a great job protecting themselves from the most serious forms of coronavirus. disease, said Dr. Carlos Baleeiro, a pulmonologist and critical care specialist at CHI Memorial Hospital.
“The progress does not mean that the vaccine has failed. It means that the vaccine has a success rate and some people may have a symptomatic infection,” said Baleeiro, who added that it was expected that the vaccine efficacy decreases as the virus mutates into new variants. , such as the delta variant that now predominates.
“If you look at the total effectiveness against the delta, it decreases compared to the effectiveness against previous variants, but if you look at the prevention of serious infections and death, it’s still very, very good,” he said.
Data on advanced cases are limited and follow-up varies widely between states and localities, meaning that much of the understanding of advanced infections comes from anecdotes.
Figures fluctuate daily, but when Baleeiro checked the hospital’s COVID-19 patient makeup last week, he was about 80% unvaccinated and 20% vaccinated. There were also no vaccinated patients in the intensive care unit, he said.
The vast majority of hospitalized vaccinated patients are also older, have a chronic disease that makes them more vulnerable, or a weakened immune system, making all vaccines (not just one against COVID-19) less effective.
“They may have a more significant advanced infection, but they are much more likely to have a worse outcome without the vaccine,” Baleeiro said. “This is a small sample of a hospital, but the pattern is what we would expect.”
Hyde described similar trends to Erlanger.
“I can only talk about my personal experience, but I still have to have one person vaccinated in the ICU. I’ve had a handful on the ground and they’ve all gone home,” he said. “I’ve had a 92-year-old vaccine completely vaccinated. I admitted it did better than a 30-year-old unvaccinated, so if that’s not evidence of effectiveness, I’m not sure what it is.”
Parkridge Health System declined to comment on this story.
Both Hyde and Baleeiro said there is a perception problem when it comes to advanced cases, and one of the main reasons they are becoming more common is that more than 170 million Americans are completely vaccinated.
“As more people get vaccinated, everyone will know someone who was vaccinated and has the disease, but that’s not a vaccine failure. It’s just math,” Baleeiro said. “Part of the reason people post or share, or why everyone knows a story about someone who had the vaccine and is now sick, is because this is less common and something new that catches your eye. It’s more memorable “.
Hyde said the high level of community outreach combined with a low vaccination rate and the return to face-to-face activities without precautions also contribute to the increase in advanced cases.
“Numerically, the number of COVID cases in the region has increased by thousands of percent compared to the beginning of June, so that the number of patients with COVID in the hospital, point, is exponentially higher than ago a few weeks, ”he said. dit. “You could have a single-layer approach (i.e. I’m completely vaccinated) if the community spread is very low. If the spread is very high, a multilayer approach will be more effective, but you’re still exponentially less likely ending COVID [when vaccinated]. “
Elizabeth Forrester, technical director and co-founder of Athena Esoterix – formerly the Baylor Esoteric and Molecular Lab – said the lack of quality data on advanced infections is frustrating from a research standpoint.
On May 1, U.S. Centers for Disease Control and Prevention stopped investigating advanced cases unless they resulted in hospitalization or death. This decision now faces criticism from some experts who say reducing those efforts leaves researchers unable to answer important questions:
– When does immunity for vaccinated people begin to decline?
– Are the new variants more able to evade vaccines?
– Are certain demographics more prone to advanced infections?
– Do advanced infections produce similar long-term effects as unvaccinated infections?
Identifying groups of vaccine advances could also help identify manufacturing or storage and handling problems.
On the other hand, some say that monitoring an expected outcome is not the best use of finite public health resources.
The Tennessee Department of Health’s latest COVID-19 Critical Indicators Report, dated Thursday, states that advanced cases account for 1.7% (or 16,296 of 977,230) of the state’s total confirmed cases. , but this number is likely to be a significant subcount. Many who become infected after vaccination will not be sick enough to notice or seek evidence, and until recently, the CDC did not recommend that vaccinated people be tested after exposure, according to Johns Hopkins.
Of Tennessee’s 23,889 hospitalizations, 368 (1.5%) occurred in people who were completely vaccinated, according to the Critical Indicators Report. Meanwhile, 108 (0.8%) of a total of 13,142 deaths occurred in fully vaccinated individuals.
From May to July, 90% of confirmed cases, 88% of hospitalizations and 94% of deaths from COVID-19 in the state were among the unvaccinated, according to the report, which also notes that the department “currently conducts more robust active surveillance for hospitalized COVID-19 cases that are vaccinated than those that are not vaccinated; therefore, hospitalization data among the unvaccinated may be incomplete. “
At the start of the vaccine launch, Forrester’s lab focused heavily on trying to “sequence” the genetic composition of advanced cases from positive COVID-19 samples that the lab processes from suppliers in the area. Sequencing is the laboratory technique that detects variants of the virus.
“But we were not able to sequence them, which indicated that the viral load was so low that, although there was a breakthrough for that individual, the chances of transmitting the virus to other people were really very low. , and all of this followed very well what we expected to happen, “Forrester said, adding that there is no compelling reason to follow these cases.
Then, the rapid rise of the delta variant caused a curve ball. Forrester said test results of vaccine advances began to show viral loads as high as people who were not vaccinated. Similar findings in other parts of the country prompted the CDC to revise its facial mask guidelines to re-include vaccinated people and begin advising people with certain immune conditions to seek reinforcing features. From September, reinforcements will be recommended for fully vaccinated people who have spent at least eight months since their last dose.
(READ MORE: Hamilton County Department of Health recommends face masks for everyone, including schools)
“We need both masks and vaccines, and it’s really discouraging and sad that we can’t convey that message effectively,” Forrester said. “This happens to us all in real time. People say, ‘Vaccines fail.’ They don’t fail, the virus has changed. what has happened has caught a lot of people in suspicion. “
Hyde said transmission is complicated and that viral load is just one of the many contributing factors and that better data is needed before the medical community fully understands the ability of a vaccinated person to spread the disease. Because the immune systems of vaccinated people know about the virus, it will not be able to replicate as much in the body, he said.
“The period of infection for someone who is vaccinated will be much shorter than someone who is not vaccinated, so to say that vaccinated people have the same probability of spreading, even from these very data. limited, not an accurate statement, “said Hyde, who added that vaccinating more people is still” the biggest piece of the puzzle. “
“It’s just not an option to indulge in that, and in many ways we missed the window to avoid that wave,” he said. “We are a country with a lot of resources and it has some of the most effective vaccines of the 21st century, for free, and in our county 52% of people chose not to. And this is one of the reasons why we are where We are. “
Contact Elizabeth Fite at [email protected] or follow her on Twitter @ecfite.