Are Vaccinated People at Risk of the Delta Variant?
COVID instances are increasing as breakthrough cases are spreading to previously vaccinated individuals. "By no means does that mean that you're dealing with an unsuccessful vaccine."
The Pfizer and Moderna vaccines have demonstrated astounding — and nearly comparable — levels of efficacy.
When administered in two doses, the Pfizer vaccine demonstrated effectiveness of 95% in preventing symptomatic Covid infection. According to the findings, the vaccine proved to be more or less similarly protective across age ranges, as well as across racial and ethnic groupings
After the second dosage, the Moderna vaccine was 94.1 percent effective at preventing symptomatic Covid-19 infection.
It was discovered that the J&J one-dose vaccine was found to be 85 percent protective against serious disease, with no differences seen between the eight countries or three areas studied, nor across the age groups of those who took part in the clinical trial. In addition, there were no hospitalizations or fatalities in the vaccine arm of the trial following the 28-day period during which immunity was established in the participants.
So why is anyone surprised to learn the three leading vaccines are not 100 percent effective, and many infected people have been previously vaccinated?
But even more surprising, is anyone surprised to learn that the current Delta Covid variant numbers are rising at pandemic levels from anti-vaxers who elected not to be vaccinated?
As a result of the highly contagious variety and a lagging vaccination campaign and the near lack of preventive restrictions, cases are rapidly increasing in all states, increasing hospitalizations in nearly all states.
While the trend appears to be concerning, breakthrough infections — those occurring in people who have received vaccinations — are still considered to be rare, with those resulting in serious illness, hospitalization, or death is even more unusual. Over 97% of those admitted to hospitals with Covid-19 had not received a vaccine.
Dr. Anthony S. Fauci, the Biden administration's top pandemic adviser, said during a news briefing on Thursday that reports of breakthrough infections should not be interpreted as evidence that immunizations are ineffective.
"By no means does that mean that you're dealing with an unsuccessful vaccine," he said. "The success of the vaccine is based on the prevention of illness."
Vaccinated individuals can still develop infections, which are typically asymptomatic or minor.
That may surprise many vaccinated Americans, who frequently believe they are entirely immune to the virus.
Furthermore, as yet unresolved, breakthrough infections present the prospect that vaccinated individuals may transfer the virus to others.
Given the virus's upwelling across much of the country, some scientists believe it is time for vaccinated people to consider wearing masks indoors and in crowded places such as shopping malls or concert halls. This recommendation goes beyond current CDC guidelines, which recommend masking only for unvaccinated people.
According to a federal official who spoke on the condition of anonymity because he was not authorized to comment on the subject, the CDC has no plans to amend its rules until there is a significant shift in science.
"Seatbelts reduce risk, but we still need to drive carefully," said Dr. Scott Dryden-Peterson, an infectious disease physician and epidemiologist at Brigham & Women's Hospital in Boston. "We're still trying to figure out what is 'drive carefully' in the Delta era and what we should be doing."
The mystery around Delta stems in part from the way it varies from prior coronavirus variants.
Although it is transmitted in the same way as the original virus — through inhalation, usually in enclosed spaces — Delta is believed to be around twice as contagious as the original virus.
Notably, early evidence suggests that persons infected with the Delta version may carry approximately 1,000 times the virus as those infected with the original virus.
While this does not appear to indicate that they become sicker, it does suggest that they are more contagious and for a longer period.
Additionally, the dose is critical:
A person who has been vaccinated and is exposed to a low dosage of coronavirus may never become ill or may become infected in a non-noticeable way.
When vaccinated individuals are exposed to exceptionally high viral loads of the Delta variety, their immune responses are more likely to be overcome.
The problem exacerbates as community transmission rates increase, as the dose and number of exposures increase.
Vaccination rates in the country have plateaued, with fewer than half of Americans fully inoculated, providing ample opportunity for the virus to spread.
Unvaccinated individuals "are not, for the most part, taking measures," according to Dr. Eric J. Rubin, editor in top of the New England Journal of Medicine.
"We're all susceptible to whatever anyone's behavior is in this epidemic."
A breakthrough infection is likely to be insignificant for the ordinary vaccinated person, causing little to no symptoms.
However, experts are concerned that a small number of vaccinated individuals who contract the virus may develop protracted Covid, a poorly known constellation of symptoms that remains after the active infection has subsided.
It is expected that immunity, boosted by vaccines, will quickly recognize and eliminate the virus after an infection, preventing severe damage from occurring.
Apart from anecdotal reports, there is less data to suggest that breakthrough infections with the Delta type are more common or more likely to spread to other persons.
The CDC has documented approximately 5,500 hospitalizations and deaths among vaccinated individuals, but not milder breakout illnesses.
If a vaccinated individual becomes infected may depend on the level of antibodies spiked following vaccination, the potency of those antibodies against the variation, and whether the level of antibodies in the person's blood has decreased since vaccination.
Health officials should also educate the public on how vaccines work — preventing people from becoming seriously ill, according to Kristen Panthagani, a geneticist at Baylor College of Medicine who blogs about complicated scientific topics.
"Vaccine efficacy is never 100 percent," she explained.
"Similarly, we should not anticipate Covid vaccinations to be faultless. That is an unreasonable expectation."