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U.S. Coronavirus: Spread of Delta Variant May Make Obtaining Collective Immunity Even More Difficult, Expert Says


“We don’t know exactly what the collective immunity percentage would be for Covid-19. It would be different for the Delta variant, and higher, because it is more transmissible,” Dr Rachel Levine, assistant secretary in the US Department of Health and social services, CNN’s Ana Cabrera said Friday.

Estimates vary on the proportion of the population that needs to be immunized to achieve this goal. Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said herd immunity could be achieved if 70 to 85% of people are immune.

There is good news, according to Levine, who said, “People vaccinated are protected against this Delta variant. And they are extremely unlikely to get sick and it is virtually impossible for them to require hospitalization.”

As for those who remain unvaccinated, “The Delta variant poses a threat,” Levine said.

Variant representing a higher percentage of cases in some states

The Delta variant, first seen in India, can infect people more easily and cause even more serious illness.

In California, where about half of the state’s 40 million people are vaccinated, cases of Covid-19 are on the rise, with the Delta variant accounting for 36% of all new cases, officials say.

“The most important thing we can do to stop the spread of COVID-19 and its variants is to ensure that all eligible people are vaccinated,” said Dr. Tomás Aragón, California Public Health Officer .

On Monday, Los Angeles County recommended that people wear masks in indoor public spaces even if they were vaccinated, and on Friday, the city and county of St. Louis, Missouri, followed suit. Both jurisdictions made recommendations due to the spread of the variant.

“As we monitor the Delta variant, we see that it spreads quickly and the data shows that it is more contagious and has an impact on younger segments of the population,” said Dr Fredrick Echols. , Acting Director of the City of St. Louis Department. Health, in a press release.

“Missouri is in a very bad situation right now,” said Dr. Megan Ranney, emergency physician and CNN medical analyst. She said the state was seeing a “dramatic increase” in Covid-19 cases, similar to that seen last summer.

“You have places in Missouri where only 10%, 15%, 20% of their residents are fully vaccinated. This new Delta (variant) is going to spread like wildfire there,” she said. declared. “They have no choice but to put up mask warrants while they also try to bring in vaccines.”

Regarding the Los Angeles County mask warrant, Ranney said that “in the face of this increase in the number of cases, reinstalling an indoor mask warrant is not the worst thing in the world.”

Such a warrant will send a signal to people that they should wear a mask if they are not vaccinated. But the problem is, she noted, that people who are not vaccinated are also the least likely to wear a mask.

CNN analyst Dr Leana Wen told CNN on Friday that states with the lowest vaccination rates were seeing an even higher percentage of the Delta variant in new cases.

“In the five states with the highest rate of spread of Covid-19, the Delta variant accounts for over 50% of cases there. Arkansas is at 50%. Utah at 60%. Missouri is at 70%. said Wen. “I think we also have to keep in mind the statistics of people who get sick. Overall these are unvaccinated people.”

People cross Las Vegas Boulevard on July 2, 2021. Tourists are flocking to the city again, and gambling revenues have hit an all-time high.  But that progress is under threat: Nevada this week recorded the highest rate of new Covid-19 cases in the country.

Where are the US states in terms of immunization?

As of Friday, 47.1% of the total United States population were fully vaccinated and 54.7% had received an injection, according to federal data. Over the past week, an average of 662,906 people have been fully immunized daily.

According to the United States Center for Disease Control and Prevention, 18 states have fully immunized more than half of their populations. These are California, Colorado, Connecticut, Delaware, Hawaii, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia and Washington, as well as Washington, DC

Experts agree that the best protection against the Delta variant is vaccination.

Two weeks after the second dose, the Pfizer / BioNTech vaccine is 88% effective against symptomatic infections caused by the Delta variant, Fauci said. Those who received only one dose have less protection.

Moderna’s vaccine has been found in lab experiments to work against new variants, including the Delta strain, the company said this week. Serum samples from people who received two injections of the Moderna vaccine showed neutralizing activity against the variants, Moderna said in a preprinted study that has not yet been peer reviewed.

Johnson & Johnson said its single-injection coronavirus vaccine provides immunity that lasts for at least eight months and appears to offer protection against the Delta variant.

WHO travel advice

Fauci offered a glimmer of good news ahead of the July 4 holiday: Americans can celebrate with the proper precautions, he said.

“That is, if you have been vaccinated, you have a high degree of protection. If you are not, you should wear a mask and you should think very seriously about getting vaccinated”, a- he declared.

However, US Surgeon General Dr Vivek Murthy said he was most worried about unvaccinated people heading for the holiday weekend.

“If you are not vaccinated and if you are going to travel and see other people from various households, congregate inside and if you are not masked, then there is a significant risk that the virus will continue to spread. spread, ”he told CNN. Friday.
The July 4th trips will return with a vengeance as Americans

People are traveling in ever-increasing numbers: The Transportation Security Administration said it screened 2.19 million people at airports across the country on Friday. This is the highest number since the start of the pandemic and higher than the same day in 2019, before the pandemic.

AAA expects 47.7 million people to travel by road or plane between July 1 and July 5, a 40% increase from the July 4 vacation last year.

Meanwhile, the World Health Organization’s new interim international travel guidelines released on Friday take into account vaccine status as well as worrisome and interesting variants.

The organization recommends that a “risk-based approach” be followed when implementing Covid-19 measures.

“This approach should take into account the risk posed by travel for import and export of cases in the context of changing epidemiology, including the emergence and circulation of viral variants of concern; expanding the rollout of COVID-19 vaccination; and lessons learned in responding to the pandemic, including on early detection and management of cases and the application of public health and social measures, ”the WHO said in a statement.

WHO also stressed that proof of vaccination should not be required as a condition of entry or exit from a country and that national authorities could consider individualized approaches when implementing testing or testing. quarantine as a condition of entry if people are immune to vaccination or have already confirmed infection.

CNN’s Cheri Mossburg, Carma Hassan, Deidre McPhillips, Maggie Fox and Naomi Thomas contributed to this report.