Breakthrough COVID Infections in Vaccinated

"Vaccines may slow spread -- yes. But many policies across [the] U.S. and elsewhere assume vaccines totally prevent spread."

"This leads to outbreaks among vax'd -- which ultimately erodes trust in the whole vaccine effort unless the expectations are set properly."

Michael Mina, epidemiologist, Harvard University

"In a lot of cases there may be a vast, historical context behind all these feelings and reasoning."

"When we look at the risks that come with being infected, all the data say getting vaccinated is your safest way to combating the virus. I think it's tough to argue right now at all against vaccination."

"We can't think of all of these people [the vaccine hesitant or reluctant] as being people who just read something on the Internet and they haven't decided the virus isn't real."

"We don't have that one specific marker that says, 'OK, you have X amount of this antibody so that gives you Y amount of years or months of protection'."

Jason Kindrachuk, virologist, University of Manitoba

What we don't want people to say is: 'All right, I should go out and get infected, I should have an infection party'."

"Because somebody could die."

Michael Nussenzweig, immunologist, Rockefeller University 

A Jerusalem health care worker prepares a dose of the Pfizer-BioNTech vaccine designed to prevent COVID-19.  AHMAD GHARABLI/AFP via Getty Images

The most recent issue of the New England Journal of Medicine published a large new study out of Israel with the finding that while the Pfizer vaccine increases heart inflammation risk [three events per 100,000 vaccinated population], among people infected with the SARS-C0V-2 virus the risk becomes several-fold higher [11 cases per 100,000]. COVID infection as well was associated with a substantially increased risk of acquiring conditions or experiencing serious health impacts such as heart attack, blood clots and bleeding within the skull or brain.

Immunity, including protection against a breakthrough infection with Delta lasts longer following a natural infection as compared to immunity conferred by two doses of Pfizer, according to a preprint paper recently published, though no one is prepared to recommend COVID parties where groups of people gathering for the specific purpose of inviting infection to acquire a more robust immunity could conceivably lead to serious consequences, including death for some among the ill-informed and impetuous.

The coronavirus has had ample time to move within the global population where it continues to mutate and produce variants of concern, some acquiring increased transmission properties. Meanwhile, a study published by the U.S. Centers for Disease Control this week, established that the effectivenss of mRNA vaccines such as Pfizer and Moderna decreased from 91 prcent to 66 percent in front line workers, once the Delta strain became dominant. Leading the CDC to advise that the trend should be interpreted with caution.

 

People line up outside Canada Place for their COVID-19 vaccination in Vancouver in late June. Data shows 'breakthrough infections' after full vaccination aren't common, and experts say that means vaccines are doing their job. (Ben Nelms/CBC)

 

"As time since vaccination increases", says the CDC, protection too might be declining. Vaccines on the other hand, remain effective controls against serious health outcomes such as hospitalization and death. At the same time, ongoing reports of diminished immunity and breakthrough infections are hugely worrying, becoming the driver for debate over enhancing protection against the virus through the expedient of a third, booster dose of vaccine.

Of 680 people in Israel, hospitalized as a result of COVID-19, 331 of the total had been fully vaccinated. People over 60 with heart disease, lung problems or other underlying health issues are primarily represented among cases of severe breakthroughs, according to a Reuters report. And then there is the issue of context, lost in the reportage on social media of highly vaccinated populations seeing rising breakthrough cases.

The proportion of vaccinated among the infected increases resulting from the vaccines' inability to provide full protection against contracting the virus simply because the number of vaccinated in the population is steadily increasing. Even so, severe cases of COVID are rare among the vaccinated. That breakthroughs occur results from the fact that no vaccine can completely inure against infection; they can, however, be relied upon to protect from more serious conditions resulting.

The lesson is that the level of immunity should be tracked. Although inoculation can't entirely prevent acquiring COVID, those who are vaccinated will be less infectious and able to clear themselves of COVID more expeditiously than can those who remain unvaccinated; they also acquire milder infections.

"The only people that are really at risk are the unvaccinated. And, in certain provinces, we're taking very serious steps to protect the unvaccinated by preventing their exposure to the virus and the vaccinated population."

"It's sad that we have to go to the extent to do that, to protect the unvaccinated. But that is what is necessary in this situation, until we get them vaccinated."

Eric Arts, professor of microbiology and immunology, Western University

MedPage Today

Delta Scenarios

COVID-19 test    Mario Tama/Getty Images

"Will vaccines end the pandemic? [Yes], because, when I looked at the data the epidemiology in Israel, the U.K., the U.S., I said the countries that have vaccinated the most aggressively have seen the fastest declines in cases per day, and they were staying down."

"But this virus spreads so fast, and is so contagious that, if 20 percent of the population is not vaccinated that will be more than enough to keep this thing going, and give it the opportunity to keep mutating."

"What does it mean, on an individual basis, if  you've been vaccinated and we've got Delta around?"

"You still shouldn't get as sick as if you had no vaccine, so there's no doubt it's better to get vaccinated."

"You might not have a high viral load in your nose, and you might not spread ... but nobody knows their nasal viral load. Which is why I'm telling people,'Wear your mask for another few months, until we see what happens here'."

Rodney Russell, professor of immunology and virology, Memorial University

"In this vaccinated group [contracting COVID], we're seeing much milder disease. And this is going to be very much the norm for the next few months, or possibly years."

Tim Spector, epidemiologist, King's College London

"What is very different about those patients [seriously ill Delta COVID patients] is that, for the most part, they have been young people, and almost all of them, in our experience in Saskatchewan, have been unvaccinated folks."

"We have not seen a single patient land in the ICU who is double-dose vaccinated."

"[A future scenario where an asymptomatic spread continues for four to eight weeks then a not-so-silent spread] and we will have the nucleus of the fourth wave. I think we do need to understand that's going to happen; we need to make sure that we continue to be cautious."

"This fall is not a reason to double down on public health measures -- certainly, I think most relaxations of public health measures are appropriate."

"This is more of a warning to double down on the efforts to vaccinate."

Dr. Hassan Masri, critical care and ICU specialist, Saskatoon

Tourists crowd in to the Midway Geyser Basin on July 14, at Yellowstone National Park in Wyoming. Yellowstone is one of many national parks seeing record numbers of visitors this summer, even as coronavirus cases are rising in many states. Natalie Behring/Getty Images

The hope pinned on vaccines coming to the rescue, that once the majority of a population received their double dose of vaccine, the pandemic would recede and just politely pass into history doesn't appear after all, to be loyal to the premise. What was assumed just over a month ago when medical science proclaimed itself timidly satisfied that the threat volume had passed; saved once again by the ingenuity of medical science, nature intervened to teach humanity yet another lesson: It isn't over until it's over.

The trio named the "Three Big Vaccinators" have gone from resounding success in defeating the SARS-CoV-2 virus to a sad comeuppance. Thinking they'd cleared the deck of further threat, relaxation orders went into effect; the population in the U.K., Israel and U.S. celebrated wildly at the prospect of a return to freedom from care over the predation of a nasty, killing virus. And then, precipitously, everything changed as a resurgence of COVID arrived courtesy of the Delta variant.

The mutation first recognized in India in the fall of last year now represents the most dominant strain on the globe. Its contagion level has hastened infection even as the world has made a strenuous effort to build mass immunity through inoculations. Without "really, really high immunity, there's going to be a tonne of virus in the population", warned Dr. Russell. Cognizant of the percentage of populations remaining vaccine-hesitant and others vaccine-hostile.

Those who have been vaccinated and still contract COVID (breakthrough infections) are not seen to be occurring at breakneck speed; vaccinating deters the virus from taking hold and when the virus does infect, its affect is significantly less impactful. No vaccine offers full protection, the vaccinated infected have a much lower rate of serious disease and much, much lower threat of death from COVID.

Confirmed cases per million in Britain are "pretty high up compared to those around us", said epidemiologist Tim Spector, where two-thirds of adults have been given two doses of an approved vaccine.The rolling seven-day average just before the July 19 "Freedom Day" was over four times higher than a month earlier, with Britain reporting over 48 thousand new cases at week's end with hospitalizations increasing over 42 percent in a single week.

Spain, Portugal, Greece and the Netherlands are seeing rebounds possibly attributable to "the very special properties of the Delta virus" which has the capacity to stick to human cells far more effectively than the original virus. The situation has seen Israel reinstate indoor mask rules, while in the U.S., an increase of 70 percent over the previous weeks has been seen in confirmed COVID cases, with deaths 26 percent higher. Where poor vaccine uptake occurred outbreaks have risen significantly.

COVID post-vaccination resembles the symptoms of a bad cold, with runny nose, headaches, sneezing and sore throat. When loss of smell is involved it is more of a recognized symptom linked to COVID. The unvaccinated are clearly at risk of becoming infected and becoming ill. "This is becoming a pandemic of the unvaccinated", stated U.S. Centers for Disease Control and Prevention Director Dr. Rochelle Walensky.

French research supports the case for a second dose. Samples of blood taken from individuals given one dose of Pfizer or AstraZeneca "barely inhibited" Delta. Two doses, on the other hand, generated a neutralizing response for 95 percent of test subjects. 

Experts believe that the Delta variant, which was first detected in India, is far more contagious than the virus that tore through the world in 2020.   Photograph by Raj K Raj / Hindustan Times / Getty