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Delta variant weak J&J vaccine, 2nd dose may be needed – MedicineNet Health News

By Ernie Mundell and Robin Foster Health Day Reporters

WEDNESDAY July 21, 2021

Johnson & Johnson’s single-dose coronavirus vaccine is much less effective against the highly contagious Delta variant than against the original virus, new research shows.

“The message we wanted to get across was not that people shouldn’t get the J&J vaccine, but we hope that in the future it will be boosted with another dose of J&J or a boost with Pfizer or Moderna.” , study author Nathaniel Landau, a virologist at NYU’s Grossman School of Medicine, said The New York Times.

The disturbing news came on the same day that Dr Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, told lawmakers that the Delta variant now accounts for 83% of new coronavirus cases in that country.

“This is a dramatic increase, up from 50% for the week of July 3,” Walensky said at a Senate committee hearing on Tuesday.

As disturbing as the findings of the J&J vaccine are, they come from experiments with blood samples in the laboratory and may not reflect the performance of the vaccine in the real world, theTime reported. But growing evidence suggests that the 13 million Americans who have received the J&J vaccine may need a second dose.

Experts have noted that all vaccines seem to work best when given in two doses.

“I’ve always thought, and I’ve said many times, that the J&J vaccine is a two-dose vaccine,” said John Moore, a virologist at Weill Cornell Medicine in New York City. Time.

Moore added that several studies in monkeys and humans have shown greater effectiveness with two doses of the J&J vaccine. He noted that the new study was particularly credible because it was published by a team unrelated to any of the vaccine makers.

The latest findings contradict those of smaller studies released by the company in early July which suggested that a single dose of the vaccine works against the variant for up to eight months after the vaccine is administered, the Time reported.

The new study was published online on the preprint server BioRxiv and has not yet been peer reviewed or published in a medical journal. But this dovetails with observations that a single dose of the AstraZeneca vaccine – which is similar to J&J’s vaccine – only shows about 33% effectiveness against symptomatic disease caused by the Delta variant.

In the study, Landau and colleagues looked at blood samples taken from 17 people who had been immunized with two doses of an mRNA vaccine and 10 people with one dose of the J&J vaccine.

The J&J vaccine started with lower efficacy than the mRNA vaccines (Pfizer and Moderna) and showed a greater drop in efficacy against the Delta variant. “The lower baseline means what’s left to counter Delta is very weak,” Moore said. “It’s a big concern.”

While using the J&J vaccine in a second dose may be sufficient to counter the variant, there is evidence that using an mRNA vaccine for the second vaccine, rather than another J&J vaccine, may work even better. According to Time, a number of studies have shown that combining one dose of AstraZeneca vaccine with one dose of Pfizer-BioNTech or Moderna vaccines increases the immune response more effectively than two doses of AstraZeneca.

Even though some vaccines fail against the Delta variant, vaccination rates in the United States have stalled. Less than half of the country’s population is fully vaccinated, according to CDC data, and the majority of those who are not vaccinated are unlikely to be vaccinated, according to a poll released Tuesday by Axios-Ipsos.

If many of those who resist do not get vaccinated, said Dr Anthony Fauci, the country can expect a “smoldering” epidemic for “a considerable period of time.”

United States issues toughest travel alert for Britain as cases rise there

The US government has issued its most serious travel warnings to Britain this week as coronavirus cases have risen in that country as nearly all COVID-19 restrictions have been lifted in a bid to revive the economy .

The US State Department and the US Centers for Disease Control and Prevention have announced Level 4 travel alerts and urged all Americans to avoid traveling to the UK.

“Even fully vaccinated travelers can be at risk of contracting and spreading variants of COVID-19,” the CDC said in its updated advisory.

In its notice, the State Department issued an even stronger warning: “Do not travel to the UK due to COVID-19,” the notice said.

The new warnings are not binding, but they were issued as Britain grapples with an increase in the number of new infections fueled by the Delta variant that brought India to its knees last spring.

Still, the UK government went ahead with plans to drop most social distancing measures in England on so-called ‘Freedom Day’ on Monday.

But after videos circulated widely of thousands of revelers stranded in bars and nightclubs on Monday night, the UK government said it would issue new rules requiring people to provide proof of vaccination to enter them. nightclubs and other crowded places, the Washington post reported.

These restrictions will not take effect until the end of September, Prime Minister Boris Johnson said at a press conference, after residents over the age of 18 were offered the opportunity to get vaccinated.

“I don’t want to have to shut down nightclubs anymore,” Johnson said. BBC reported. “But that means nightclubs have to do the socially responsible thing.”

Britain is now reporting a seven-day average of around 45,000 new cases daily, according to Our World in Data. Some of the country’s top leaders – including Johnson – are in quarantine after Health Secretary Sajid Javid tested positive for the virus over the weekend, the To post reported.

More than half of the British population has received two doses of the coronavirus vaccine, a level of vaccination which officials say has helped reduce hospitalizations and deaths.

Still, hospitalizations have increased by almost 40% over the past week, although Patrick Vallance, Britain’s chief scientific adviser, has said 60% of new COVID-19 patients are unvaccinated.

More information

The United States Centers for Disease Control and Prevention has more information on COVID-19[FEMININE

SOURCES: Le New York Times; CNN ; Washington Post


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source: www.medicinenet.com

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