The effectiveness of the COVID-19 vaccine dropped from 91% to 66% after the delta variant became dominant

The effectiveness of COVID-19 vaccines declined dramatically after the Indian “Delta” variant became the dominant strain in the US, a new report said.

When the Pfizer-BioNTech and Moderna vaccines were first introduced in December 2020, the vaccines were found to be 91 percent effective.

However, after a fourth surge fueled by the variant in the US, the vaccine’s effectiveness fell to just 66 percent, according to the Centers for Disease Control and Prevention (CDC).

While the vaccines are still effective at preventing hospital admissions and deaths from COVID-19, the data suggests that the Delta variant may be more capable of causing breakthrough infections.

The new report comes after the White House announced plans last week to introduce booster vaccinations in September.

It has long been speculated that the immunity provided by the vaccines would eventually wane, eventually creating the need for booster vaccinations.

The CDC notes that the effectiveness of COVID-19 vaccines fell from 91 percent to 66 percent when the Indian “Delta” variant prevailed in the United States. Pictured: A woman in Los Angeles, California receives a dose of a COVID-19 vaccine on Monday

The delta variant (orange) and its subline AY.3 now account for almost every single new COVID-19 case in the United States, according to CDC data

For the study, published Tuesday, the CDC collected data from 4,217 frontline workers for the study, of whom 83 percent – 3,483 – were vaccinated.

The researchers adjusted the data to take into account infection rates, local COVID-19 transmissions, and employment.

Before the advent of the Delta variant, the vaccines were shown to be very effective in preventing breakthrough cases.

The team created two different sets of data, one for delta variant predominance, in which more than 50 percent of cases in the area where a person lived believe it was delta variant.

The other was when the variant was not considered to be predominant.

There was a median of 20 days without vaccination in all study participants at times when the variant was not predominant.

Researchers found 194 positive COVID-19 cases in the unvaccinated group, nearly 90 percent of which were symptomatic.

Out of an average of 177 fully vaccinated days among participants who eventually received the vaccinations, only 34 infections were found.

Just over 80 percent of breakthrough cases were symptomatic.

Researchers estimated that the vaccine was about 91 percent effective before the Delta variant.

However, things changed as the variant began to take into account more cases.

There was a median of 48 days without vaccination amid the delta dominance among 488 participants.

During that time, 19 infections were identified, about 95 percent of which were symptomatic.

Of the 2,352 fully vaccinated participants, were fully vaccinated for 49 days amid delta dominance and 24 infections were detected.

Three quarters of the breakthrough cases were symptomatic.

After adjusting the data, the researchers found that only 66 percent of the COVID-19 vaccines prevented infection by the virus.

The overall effectiveness of the vaccines throughout the study was 80 percent.

The Delta variant is now the dominant strain across America, making up almost all of the newly registered cases.

There is disagreement as to whether the variant’s ability to cause breakthrough cases is a characteristic of the variant itself or a question of the diminishing effectiveness of the vaccine.

In any case, the number of groundbreaking cases across the country is growing.

Previous CDC research has shown that the viral loads of the delta variant are the same in vaccinated and unvaccinated people.

This means that vaccinated people who are infected can very easily pass the virus on to unvaccinated people.

Last week, the White House announced that COVID-19 booster vaccinations will be available shortly to bolster protection against the virus.

All Americans who have received the Pfizer or Moderna injection are entitled to a third injection eight months after receiving the second injection.

Those who received the Johnson & Johnson vaccine are still waiting for the booster to be approved.

The introduction of booster vaccinations can be controversial as some international health leaders are calling for rich nations like the US to instead donate doses of vaccine to low-income countries.

All Americans 12 and older are eligible for a COVID-19 vaccine.

Around 71 percent of the eligible population have had at least one vaccination and 60 percent are fully vaccinated, CDC data shows.

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