AstraZeneca Plc reported a slightly lower efficacy rate for its Covid-19 vaccine after the results of a US clinical trial were criticized as out of date, raising new questions about the besieged fire and potentially delaying its approval in the United States. United.
The vaccine was 76% effective in protecting volunteers from the coronavirus, the UK drugmaker said in a statement Thursday. This compares to an earlier estimate of 79%, based on data collected up to February 17.
The latest twist created another layer of uncertainty for a product already facing declining support in Europe after months of confusion and missteps. While the vaccine is still expected to play a crucial role in the fight against the global pandemic as governments around the world have ordered millions of doses, repeated mistakes risk further eroding public confidence. public in vaccination.
“The difference between 76% and 79% is rounding error, probably just a handful of cases,” said Paula Cannon, professor of molecular microbiology and immunology at the Keck School of Medicine at the University of California. South, where she leads a research team. who studies viruses. “But it’s so important for us to be completely transparent and to the point, because we are building public trust.”
The results were based on 190 symptomatic cases that developed among the 32,449 volunteers who participated in the trial, which includes 49 cases that were not counted as part of the initial analysis. The company did not disclose how many of these infections occurred in the group that received the vaccine and how many in the group that gave the placebo.
There are 14 other people with probable or possible infections, so the total number of cases may still change – which may again lead to an adjustment in the overall effectiveness rate.
Astra’s shares have changed little in London trading. The Cambridge, England-based company stressed that the marginal changes in the rate of protection did not affect the vaccine’s overall effectiveness.
“The primary analysis is consistent with our previously published interim analysis and confirms that our Covid-19 vaccine is very effective in adults,” said Mene Pangalos, executive vice president of bio-pharmaceutical research and development at the society.
“We look forward to filing our regulatory submission for emergency use authorization in the United States and preparing for the deployment of millions of doses across America,” he said.
Some of Astra’s challenges reflect the unprecedented urgency of developing the Covid-19 vaccine, in which multi-year processes have been squeezed into months.
“The problem with AstraZeneca is that they’ve had a few black eyes,” Cannon said. “I don’t think it’s malicious, it just reflects the attempt to bring out a vaccine in the midst of a pandemic.
In an unusual move earlier this week, a group of experts working with the company on the safety of its US clinical trial contacted government agencies late Monday to express concern over data AstraZeneca made public hours earlier. . The company responded by saying it would release new estimates soon.
The vaccine developed with the Oxford University was 100% effective in preventing serious illness and hospitalizations.
Older volunteers benefited the most from shooting, 85% of them aged 65 years and over protected against symptomatic Covid. The finding is particularly important because it shows that the vaccine benefits those most at risk from the virus, said Paul Griffin, director of infectious diseases at Mater Health Services and associate professor of medicine at the University of Queensland in Brisbane.
Data from trials in the United States were considered important because previous research in the United Kingdom and Brazil confused the issue by producing two different efficacy readings. Additionally, these tests failed to include enough elderly people to establish efficacy for this crucial patient group.
“Getting that message out to the community has been difficult, while other vaccines had a much simpler message,” Griffin said. “Having a much more complex one – with many different facets posted at different times – confused people as well. This made some people worried.
– With the help of Dong Lyu
(Updates with Astra shares in the seventh paragraph)