Delta variant caused more severe breakthrough cases than expected, 10 times higher risk for unvaccinated – NBC New York

A new CDC study released Friday provides what may be the most shocking evidence to date of the threat the highly contagious delta variant may pose to fully vaccinated people, especially since it has usurped all other strains. of COVID-19 to dominate U.S. cases.

What is also clear however: This danger is magnified 10 times for people who are not fully immune to the virus, the researchers found.

The health agency analyzed the percentages of the total number of cases, hospitalizations and deaths by vaccination status in 13 jurisdictions, including New York City, between April 4 and July 17, when the prevalence of delta in the United States has gone from less than 1% of new weekly cases to 90%. new cases weekly.

(That’s now nearly 99% of positive American samples tested, according to the CDC – and at least 98% of all those tested in New York and New Jersey in the past month.)

We thought we could control the pandemic with about 70% of the country vaccinated. But with the Delta variant resulting in an increase in cases even in highly vaccinated countries, it changes the math. We may need 90% to take the COVID-19 vaccine to really argue with this variant, says Alabama epidemiologist Dr. Suzanne Judd.

During this period, those fully vaccinated in the 13 jurisdictions studied accounted for 9% of new COVID deaths and 8% of new hospitalizations. They accounted for 8% of new cases over the same period, although health officials at all levels of government are consistently more concerned with the first two metrics, which indicate the most serious outcomes associated with COVID infections.

Without a doubt, vaccination (this CDC report did not report breakthrough cases by vaccine brand, in particular) has been a proven protector. Ninety-one percent, 92% and 92%, respectively, of deaths, hospitalizations and cases associated with COVID during the period April 4 to July 17 were among the unvaccinated. But any apparent risk to fully immune people has been a critical issue in recent months.

CDC

And the risk only appeared to intensify as the weekly prevalence of delta increased, according to CDC research. This latest study split the research schedule into two time periods – April 4 to June 19, when the prevalence of delta increased significantly, and June 20 to July 17, when it took over the United States and of the whole world.

In the first date range assessed, fully vaccinated people accounted for 8% of new COVID deaths, 7% of hospitalizations and 5% of cases. These percentages increased significantly during the study period from June 20 to July 17 – to 16% of new COVID deaths, 14% of new hospitalizations and 18% of new COVID cases.

CDC

Full vaccination rates in the 13 jurisdictions studied increased between the two periods – from 37% in the first period, April 4 to June 19, to 53% in the second, June 20 to July 17. Based on research that assumes 90% vaccine effectiveness, CDC says it would have expected those vaccinated to account for 6% of new cases, which is close to the 5% seen, in the first period. studied and around 10% of new cases in the second, which fell well below the 18% found.

Fully vaccinated people representing 18% of new COVID cases during the period June 20 to July 17 would have been expected if the vaccine’s effectiveness was 80%, the CDC said. As the prevalence of delta exceeded 50%, the percentage of fully vaccinated among new COVID cases in each age group increased at rates reflecting this lower vaccination effectiveness threshold of 80%, the researchers said. .

Increases in hospitalizations and deaths from COVID among vaccinated people aged 65 and older have also appeared higher than expected, according to the CDC. Yet the overwhelming delta of risk posed to unvaccinated people is clear in this latest data – a fact that officials in New York City and elsewhere are working to cement in the minds of the United States.

The new rates of death, hospitalization and cases were significantly higher among unvaccinated people than among those vaccinated in all 13 U.S. jurisdictions. This latest CDC study says its findings are consistent with previous research indicating that delta is more likely to cause breakthrough infections than other strains, but not more likely – in a statistically significant sense – to cause more severe results. serious.

Even after delta became the most dominant variant, fully vaccinated people were five times less likely to be infected with COVID, 10 times less likely to be hospitalized because of it, and 10 times less likely to die from complications. associated with the virus compared to unvaccinated people, the CDC found.

“The results were consistent with a potential decline in vaccine protection against confirmed SARS-CoV-2 infection and strong and continued protection against hospitalizations and deaths associated with COVID-19,” the study said. CDC.

“Getting vaccinated protects against serious illnesses caused by COVID-19, including the Delta variant, and monitoring the incidence of COVID-19 by vaccination status could provide early signals of changes in vaccine-related protection that may be confirmed by well-controlled studies of the efficacy of the vaccine. Says the study.

CDC

The researchers identify a number of limitations in their study, including the addition of partially vaccinated people to their unimmunized assessment, delays in death reports, assumptions about when the weekly prevalence of delta cases reaches 50% and the fact that the 13 jurisdictions represent only 25% of the US population.

Locally, both New York and New Jersey, are grappling with their most intense new cases and hospitalizations since May – although none of the latest figures compare slightly with those for spring 2020.

New York Gov. Kathy Hochul, who addressed the delta variant in her first speech as governor as well as in the days leading up to her official swearing-in, reported a new daily case total of 6,151 on Friday, the toll of highest day since April. 16.

She also reported 43 new daily deaths, the highest single-day number since April 30 (44), though Hochul kicked off his administration by reporting those numbers differently than his predecessor.

Based on New York state data, it’s unclear how many new deaths and cases are due to groundbreaking cases.

The US government has also strongly acknowledged the threat from the delta. President Joe Biden on Thursday unveiled a six-point plan to tackle the threat of this variant, including new vaccination warrants and school recommendations.

Check out all the highlights of Biden’s new Delta variant strategy here.

We thought we could control the pandemic with about 70% of the country vaccinated. But with the Delta variant resulting in an increase in cases even in highly vaccinated countries, it changes the math. We may need 90% to take the COVID-19 vaccine to really argue with this variant, says Dr. Suzanne Judd, epidemiologist from Alabama.