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Russians publish early coronavirus vaccine results



On Friday, a team of Russian scientists released the first report on their Covid-19 vaccine, which had come under severe criticism for President Vladimir Putin’s decision last month to approve it before clinical studies had shown it to be safe and effective.

In a small group of volunteers, the scientists found that the vaccine produced low levels of antibodies against the coronavirus and caused only mild side effects. However, research has not yet shown whether vaccinated people are less likely to become infected than those who are not.

In August, Putin announced with great enthusiasm that the vaccine ̵

1; called Sputnik V – “works effectively enough” to be approved. He declared his approval as “a very important step for our country and generally for the whole world”.

However, the vaccine developers condemned the decision, finding that no data on the vaccine had been released. In addition, the critics said, the Russian scientists had yet to conduct a large test on tens of thousands of people to prove that a vaccine works.

The new paper, published in the Lancet, contains the first public data from Sputnik V’s clinical trials. Independent scientists were impressed with the accuracy of the work.

“The science seems impeccably done,” said Naor Bar-Zeev of the Johns Hopkins Bloomberg School of Public Health, who co-authored a comment on the new article. Even so, he warned that no one will know whether Sputnik V is safe and effective until the larger trials are completed.

“We should welcome a Russian vaccine when it is successful, and we should welcome other vaccines when they are successful,” said Dr. Bar Zeev. “But they should all be rated equally rigorously.”

Researchers at the Gamaleya Research Institute in Moscow used a design for the vaccine they had previously developed and tested for MERS, a disease caused by another coronavirus.

The Sputnik V vaccine stimulates the immune system by causing a person’s cells to make a protein normally found on the coronavirus that causes Covid-19. The researchers loaded the gene for this viral protein into a second virus called the adenovirus.

When injected into the arm, the adenovirus slips into the muscle cells. It has been genetically engineered so that it cannot make copies of itself or cause disease. Once the coronavirus gene gets into a cell, the cell begins making the protein.

Similar adenovirus-based vaccines are also being tested by several other teams, including AstraZeneca, CanSinoBio, and Johnson & Johnson.

Each team tests a different strain of adenovirus. In contrast to the others, the Russian team combines two adenoviruses into one vaccine. For their first clinical study, Gamaleya researchers gave the volunteers an initial shot of an adenovirus called Ad26 and three weeks later a shot of one known as Ad5.

In the Lancet publication, the researchers said they tested the vaccine on hamsters and monkeys. They claimed the animals were protected against the coronavirus with no harmful side effects, but did not present any data on these studies in their new publication.

The study they conducted on human volunteers was a so-called phase 1/2 study. It was small: only 40 volunteers received the full vaccine with both types of adenoviruses. Nobody was given a placebo.

For comparison, the Chinese company CanSinoBio conducted a phase 1/2 study that included 382 people who received the vaccine and a further 126 people who were given a placebo.

The Russian vaccine caused mild symptoms in a number of subjects, the most common of which were fever and headache. Other adenovirus-based vaccines have produced similar side effects.

“You are expecting some symptoms – this is normal,” said Dr. Bar Zeev.

The researchers found that volunteers given the full vaccine produced antibodies that could block the virus from replicating in cells.

To measure the performance of their vaccine, the Russian researchers compared antibody levels to samples from people who had recovered from natural infections with Covid-19. Convalescent plasma, as these samples are called, contains antibodies to the virus that humans make themselves.

In the work, the researchers said that vaccinated people had the same levels of antibodies as those found in convalescent plasma.

Akiko Iwasaki, an immunologist at Yale University who was not involved in the study, said the vaccine “produced good levels of antibodies” in all of the volunteers.

However, in a press release, the Gamaleya Institute implied that its vaccine was superior to AstraZeneca’s. It said the level of antibodies from vaccinated volunteers was “1.4-1.5 times higher than the level of antibodies from patients who had recovered from Covid-19”.

AstraZeneca only produced antibody levels that matched those in convalescent plasma.

It is not clear why the paper shows a different picture. The study’s authors did not respond to a request for comment.

John Moore, a virologist at Weill Cornell Medicine in New York who was not involved in the study, said it was too early to make meaningful comparisons between the various Covid-19 vaccines. Each team uses different tests to measure antibody levels. And each group of recovered patients they screen for convalescent plasma may have different levels of antibodies.

“We have long suffered from the apple versus oranges scenario, but now we are in the fruit salad field and it drives me to try bananas to figure it all out,” he said.

One thing is clear, however: no phase 1/2 study can prove protection against Covid-19.

This requires a so-called phase 3 study in which a large number of volunteers are given either a vaccine or a placebo. A phase 3 study can also reveal harmful side effects that have been overlooked in small preliminary studies.

In their paper, the Russian scientists wrote that on August 26 they received approval to conduct a phase 3 study with 40,000 people. There are currently seven other vaccines in these late-stage studies. Johnson & Johnson is expected to start its own Phase 3 trial later this month, and Novavax is expected to start its own Phase 10 trial in October, bringing the total to 10.

Phase 3 trials can take months to produce clear results, said Dr. Bar-Zeev, and even then, they need to be carefully reviewed before any decision is made on large-scale vaccine use.

“Yes, we all want a vaccine, but we don’t want to make a mistake,” he said. “So stay tuned and wait so we know what we’re getting into.”

Andrew Kramer contributed to reporting from Moscow.


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