By Kate Kelland and Julie Steenhuysen
LONDON/CHICAGO (Reuters) - Scientists who have watched with dismay a series of disputesover AstraZeneca's COVID-19 vaccine say strong efficacy data from a large U.S. trial should lay concerns to rest, but worry the skirmishes may leave a lasting mark on public trust.
Spats with governments across Europe about production, supplies, possible side effects and the vaccine's merits have dogged the Anglo-Swedish drugmaker for months. And a highly unusual public rebuke from U.S. scientists monitoring the government-funded trial this week added to its woes.
While the disputes have raised questions about AstraZeneca's messaging and communications, what is crucial, scientists say, is that the product at the heart of all this appears sound.
On Thursday, the company said the vaccine was 76% effective in an updated analysis of its U.S. trial after providing a slightly higher efficacy figure that was criticized for not being based on the most up-to-date data.
"One has to distinguish between the strong, positive, data from the U.S. trial on the one hand, and the amazing ability of AstraZeneca's press-release messaging to continually rescue defeat from the jaws of victory," said Danny Altmann, a professor of immunology at Imperial College London.
Among researchers working to develop vaccines, treatments and other weapons against COVID-19, the frustration is evident.
Altmann told Reuters he is "impatient to get politics out of vaccinology and get us safe."
A U.S. trial investigator involved in evaluating AstraZeneca's shot, who was not authorized to speak publicly, called the avoidable controversy "upsetting, because a lot of people worked really hard and the vaccine is really important. I do think it's a good and effective vaccine."
AstraZeneca defended its handling of U.S. trial data this week, saying in a statement it was "in the public interest" for the company to disclose the interim results that shed more light on the vaccine's ability to protect older adults and its safety.
AstraZeneca's COVID-19 shot has faced questions since late last year, when the drugmaker and Oxford University published data from its first large-scale trial with two different efficacy readings as a result of a dosing error.
Uncertainty over how the dosing error came about raised questions about the robustness of the data, and differing accounts from AstraZeneca and Oxford added to concerns
Trust in the vaccine - and its developers - took a further hit this month, when more than a dozen countries temporarily suspended its use after reports of a rare blood clotting disorder in a very small number of people shortly after they were inoculated.
Ian Jones, a professor of virology at Britain's Reading University, said it is "generally accepted that the early trial data, while positive, did suffer from a communication issue."
The focus now, he agreed, should be results from the latest trial and from real-world use "which shows an excellent safety profile and the prevention of severe disease."
AstraZeneca's coronavirus vaccine has so far been most widely used in Britain, where its rollout January, along with the Pfizer/BioNTEch shot, is helping reduce severe COVID-19 cases and deaths.
U.S. scientists were taken aback on Tuesday by a midnight news release issued from the National Institutes of Health (NIH) raising doubts about the company's announcement a day earlier that the vaccine was 79% effective at preventing COVID-19 in the U.S trial.
That was prompted by a letter from an independent data and safety monitoring board to the NIH saying the company had excluded more current data, which top U.S. infectious disease expert Dr. Anthony Fauci called "a really unfortunate unforced error."
That assessment seemed to be backed up by the updated results released by AstraZeneca on Thursday that were only marginally different.
"To have them write to the trial sponsor, which is the NIH, to say that they see a problem - no one I know has ever heard of this," said John Moore, a professor of microbiology and immunology at Weill Cornell Medical College in New York. "It's damaged the company's reputation in Washington, D.C. circles. It's tarnished."
Asked whether the NIH was satisfied with AstraZeneca's latest news release, a spokesperson said via email, "NIH looks forward to the review by the U.S. Food and Drug Administration."
FDA staff scientists routinely make public their own review of a drug's raw data after it is submitted to the agency for approval.
Some U.S. scientists plan to wait for the FDA analysis, rather than judge the vaccine's merits based another press release, "just to avoid any further roller coaster rides," said Dr. Nahid Bhadelia, an infectious disease expert at Boston Medical Center.
(Reporting by Kate Kelland in London and Julie Steenhuysen in Chicago; Editing by Bill Berkrot)