Text size
Jason Alden / Bloomberg
Data on the Covid-19 vaccine in development by AstraZeneca and the University of Oxford published in The Lancet on Monday looked positive, but the stock fell after rising last week due to high expectations for the data.
Shares of the US deposit receipt for AstraZeneca (ticker: AZN) rose 7.5% on July 15 and 6.4% on July 17 in reports that the data would be positive.
Now that the official report is here, the data looks promising. The researchers reported only mild and moderate adverse events in subjects who received the vaccine, and said that the vaccine induced levels of neutralizing antibodies that were similar to those seen in patients who had recovered from Covid-19 infections. They also reported that the vaccine induced T-cell responses, another type of immune response that is considered important in preventing Covid-19 infections.
However, the newspaper publication did not lift AstraZeneca stocks. AstraZeneca’s ADR shares fell 3% when the document was released, before recovering slightly. At 11 am EST, shares fell 2.1% during the day, trading at $ 59.82.
“The immune responses observed after vaccination are in line with what we hope will be associated with protection against the SARS-CoV-2 virus, although we must continue our rigorous clinical trial program to confirm this,” said the chief investigator of the Oxford Vaccine. The trial and study co-author Andrew Pollard said in a statement.
In a press release distributed at the same time as Lancet’s article was published, AstraZeneca noted that the vaccine induced T-cell responses in all participants, peaking at two weeks and lasting two months. Neutralizing antibodies were present in 91% of patients after one month, and in the 10 patients who received two doses of the vaccine. In both cases, the antibody levels were in the same range as that observed in patients who had recovered from Covid-19 infections.
The neutralizing antibody response may not have been sufficient to impress investors. Although comparing the studies is challenging given the different methods, ways of measuring neutralizing antibodies, and recovered patient sets of Covid-19 to provide a baseline, other Covid-19 developers have claimed more relative levels high neutralizing antibodies. Moderna (MRNA), for example, has said that its two-dose vaccine caused neutralizing antibody levels that were four times higher than in a small group of patients who had recovered from Covid-19 infections.
Adverse reactions to the vaccine were minimal. “Most of the reported adverse events were mild or moderate in severity, and all were self-limiting,” the article reported in The Lancet. Most of the patients who received the vaccine reported fatigue. Others reported muscle pain, chills, and fever. The severity of the reaction was greater one day after injection.
The vaccine “was safe, tolerated and immunogenic, while reactogenicity was reduced with paracetamol,” the document concluded. “A single dose elicited humoral and cellular responses against SARS-CoV-2, with a booster immunization that increases neutralizing antibody titers. The preliminary results of this first human clinical trial supported the progression of clinical development in ongoing phase 2 and 3 trials. “
Phase II / III trials of the vaccine are already underway in Brazil, South Africa and the United Kingdom. The U.S. government’s vaccination effort Operation Warp Speed has said it aims for the AstraZeneca vaccine to be ready for distribution in October.
Also on Monday, Pfizer (PFE) and BioNTech (BNTX) announced an agreement to supply 30 million doses of their Covid-19 vaccine to the UK, and revealed promising data on a Phase I / II trial of the vaccine in Germany.
Write to Josh Nathan-Kazis at [email protected]
.
