An experimental coronavirus vaccine developed by Johnson & Johnson protected monkeys from infection in a new study. He is the second vaccine candidate to show promising results in monkeys this week.
The company recently began a clinical trial in Europe and the United States to test its vaccine on people. It is one of more than 30 human trials for ongoing coronavirus vaccines worldwide. But until these trials are complete, which will likely take several months, the monkey data offers the best clues as to whether the vaccines will work.
“This week has been a good one, we now have two vaccines that work in monkeys,” said Angela Rasmussen, a virologist at Columbia University who was not involved in the studies. “It’s nice to be optimistic for a change.”
But he cautioned that the new results should not be used to speed up large-scale human trials. “We simply cannot take shortcuts,” he said.
Unlike many other vaccines in development that may require two injections, candidate Johnson & Johnson protected monkeys with just one dose, according to a study published Thursday in Nature.
“We saw a very reassuring level of protection,” said Dr. Dan Barouch, a virologist at the Beth Israel Deaconess Medical Center in Boston and co-author of the new study.
The study comes just two days after a similar one was published in a vaccine tested by Moderna and the National Institutes of Health.
But the two vaccines work in very different ways.
The Modern vaccine delivers a type of genetic material called “messenger RNA” into cells.
Cells use the vaccine’s RNA to produce a protein found on the surface of the coronavirus, called the spike protein, which then elicits an immune response.
RNA-based vaccines are being tested for a number of diseases, but none have been licensed for use in people.
In the Moderna study, the researchers vaccinated the monkeys by giving them two vaccines spaced four weeks apart. A month later, they infected the animals with the coronavirus. In some of the vaccinated monkeys, the researchers were unable to detect the virus in the nose or lungs. In others, the virus replicated slowly before disappearing.
Moderna began phase 3 trials of its mRNA vaccine on Monday, as did Pfizer, which is testing its own mRNA vaccine.
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The Johnson & Johnson vaccine, by contrast, is based on a virus called Ad26, which researchers have modified to carry the coronavirus peak protein gene. The Ad26 virus can enter human cells, but cannot replicate once inside them. Your host cell then uses the spike gene to make the coronavirus proteins.
This month, European regulators approved Johnson & Johnson’s Ad26 vaccine for Ebola. It was the first time that this type of virus-assisted gene delivery was approved for any disease.
In March, Dr. Barouch and colleagues designed seven variants of an Ad26 vaccine for the coronavirus. They made small changes to the spike gene to see if they could get cells to make more copies of the viral protein. They also tested variants that would make the spike protein more stable, which could elicit a stronger immune response.
Based on previous research, Dr. Barouch and his colleagues suspected that the Ad26 vaccine would be very powerful. They decided to run their experiment using just one dose, to see if that was enough to provide immunity.
The coronavirus outbreak>
Frequent questions
Updated July 27, 2020
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Should I refinance my mortgage?
- It could be a good idea, because mortgage rates have never been lower. Refinancing applications have taken mortgage applications to some of the highest levels since 2008, so be ready to get online. But the defaults have increased, too, so if you’re thinking about buying a home, be aware that some lenders have tightened their standards.
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- Many schools are unlikely to return to normal hours this fall, requiring the routine of online learning, impromptu child care, and delayed work days to continue. California’s two largest public school districts, Los Angeles and San Diego, said July 13 that instruction will be remote only in the fall, citing concerns that rising coronavirus infections in their areas pose too serious a risk to students and teachers. Together, the two districts enroll about 825,000 students. They are the largest in the country so far to abandon plans for a partial physical return to classrooms when they reopen in August. For other districts, the solution will not be an all-or-nothing approach. Many systems, including the country’s largest New York City, are developing hybrid plans that involve spending a few days in classrooms and other days online. There is no national policy on this yet, so check with your municipal school system regularly to see what’s going on in your community.
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Is the coronavirus in the air?
- Coronavirus can remain in the air for hours in tiny droplets in stagnant air, infecting people as they inhale, growing scientific evidence suggests. This risk is highest in crowded interior spaces with poor ventilation, and may help explain overcast events reported in meat packing plants, churches, and restaurants. It is unclear how often the virus is transmitted through these small droplets or sprays, compared to the larger droplets that are expelled when a sick person coughs or sneezes, or is transmitted through contact with contaminated surfaces, Linsey said. Marr, Virginia Tech aerosol expert. Aerosols are released even when a symptom-free person exhales, speaks or sings, according to Dr. Marr and more than 200 other experts, who have summarized the evidence in an open letter to the World Organization. Of the health.
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What are the symptoms of coronavirus?
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Does Covid-19 transmit asymptomatic?
- So far, the evidence seems to show that it does. A widely cited article published in April suggests that people are most infectious approximately two days before the onset of coronavirus symptoms, and estimated that 44 percent of new infections were the result of transmission from people who still had no symptoms. Recently, a senior expert from the World Health Organization stated that transmission of the coronavirus by people without symptoms was “very rare,” but later withdrew that claim.
After a single injection of the vaccine, they waited six weeks and then infected the animals with the coronavirus. Six of the seven vaccine variants offered monkeys partial protection against the coronavirus, meaning that the virus replicated only at low levels in animals.
The seventh version proved to be more powerful than the rest: five of the six monkeys that received it had no detectable virus. The sixth had only low levels in her nose.
“The fact that we could protect with a single shot in animal models was a pretty positive surprise for us,” said Dr. Paul Stoffels, chief scientific officer for Johnson & Johnson.
It was the best-performing vaccine Johnson & Johnson used last week to start its first human safety trial, the so-called Phase 1 trial. If it goes well, the company expects to enter Phase 3 trials in September, which prove no only if the vaccine is safe, but also if it works.
The company plans to test both single and double doses. Dr. Rasmussen said that a vaccine that was shown to be effective with a single dose would greatly facilitate the treatment of billions of people who need it. “Theoretically, you would need less, so you give it to more people more quickly,” he said.
Inovio, a company that develops a DNA-based vaccine, announced Thursday that the monkeys defied four months after the vaccine had a reduced burden of the virus in the nose and lungs. Their report has not yet been published in a scientific journal.
AstraZeneca and the University of Oxford have developed a vaccine based on another type of modified virus, called ChAdOx1. In May, they published promising data on monkeys, which were also published Thursday in Nature. The team is now running Phase 3 tests on people, which could produce results in October.
“It is exciting to see the number of platforms that promise a vaccine,” said Stacey L. Schultz-Cherry, a virologist at St. Jude Children’s Research Hospital in Memphis, who was not involved in any of the trials.
