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 ̵
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.
The coronavirus outbreak>
frequently asked Questions
Updated September 4, 2020
What are the symptoms of the coronavirus?
- In the beginning, the coronavirus appeared to be primarily a respiratory illness – many patients had a fever and chills, were weak and tired, and coughed a lot, although some people don’t show many symptoms at all. Those who seemed the sickest had pneumonia or acute respiratory distress syndrome and were given supplemental oxygen. By now, doctors have identified many more symptoms and syndromes. In April, the CDC added to the list of the first signs of a sore throat, fever, chills and muscle aches. Gastrointestinal disorders such as diarrhea and nausea have also been observed. Another tell-tale sign of infection can be a sudden, profound decrease in your sense of smell and taste. In some cases, teenagers and young adults have developed painful red and purple lesions on their fingers and toes – nicknamed “Covid Toe” – but few other serious symptoms.
Why is it safer to hang out together outside?
- Outdoor gatherings reduce the risk as the wind spreads viral droplets and sunlight can kill some of the virus. Open spaces prevent the virus from building up and being inhaled in concentrated quantities. This can happen when infected people exhale in confined spaces for long periods of time, said Dr. Julian W. Tang, virologist at the University of Leicester.
Why does it help to stand three feet away from others?
- The coronavirus spreads mainly through droplets from your mouth and nose, especially when you cough or sneeze. The CDC, one of the organizations using this measure, bases its six-foot recommendation on the idea that most of the large droplets that people make when they cough or sneeze fall within six feet of the ground. But six feet has never been a magical number that guarantees complete protection. For example, sneezing, according to a recent study, can trigger droplets that are far more than two meters away. It’s a rule of thumb: it is safest to stand six feet apart, especially when it’s windy. But always wear a mask even if you think they are far enough apart.
I have antibodies. Am i immune now?
- As of now, this seems likely for at least a few months. There have been appalling reports of people apparently suffering from a second attack of Covid-19. However, experts say these patients may have a lengthy course of infection, with the virus taking a slow toll weeks to months after initial exposure. People infected with the coronavirus typically produce immune molecules called antibodies, which are protective proteins made in response to an infection. These antibodies can only last two to three months in the body, which may seem worrying, but that’s perfectly normal after an acute infection has subsided, said Dr. Michael Mina, an immunologist at Harvard University. It may be possible to get the coronavirus again, but it is highly unlikely to be possible in a short window of time after the initial infection or make people sick the second time.
What are my rights if I am worried about going back to work?
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.