Call it a “half a loaf” assessment of the first Covid-19 vaccine to approach being approved for emergency use in the United States. But it’s a very good loaf.
The Food and Drug Administration announced on Tuesday that the two-dose vaccine developed at record speed by Pfizer and its German partner BioNTech provides significant protection from coronavirus infection for more than half of those who got it after just the first injection.
Pfizer announced last month that its vaccine was 95% effective after two doses administered three weeks apart, reports the New York Times, adding that the new FDA analyses “show that the protection starts kicking in far earlier.”
In a large-scale, multi-nation trial, Pfizer found that about 10 days after test subjects received their first shot, about 52% were protected. Other subjects who received shots of saline solution instead of the vaccine remained fully open to infection.
The FDA review found that the effectiveness of the Pfizer vaccine was similar “across age groups, genders, racial and ethnic groups, and participants with [other medical conditions] associated with high risk of severe Covid-19,” reports the Washington Post.
Experts are impressed.
“This is what an A+ report card looks like for a vaccine,” Akiko Iwasaki, an immunologist at Yale University, told the Times.
The FDA will consider authorizing use of the Pfizer vaccine for emergency use this week. On Thursday, the agency “will convene what’s essentially a science court that will debate — in public and live-streamed — just how strong the data backing the shots really is,” reports the Associated Press.
The need for a vaccine is urgent. According to the Johns Hopkins Covid-19 Tracker, almost 15 million Americans have tested positive for the virus and more than 284,000 have died, with the death toll rising at more than 2,000 a day.
While the Pfizer trial did not find any serious adverse events caused by the vaccine, many participants did experience short-term, flu-like side effects, including aches and fevers.
“Taking a day off after the second dose is a good thing to anticipate,” Dr. Iwasaki said.
“Severe adverse reactions occurred in less than 4.6% of participants, were more frequent after the second dose and were generally less frequent in older adults as compared to younger participants,” reports CNN, citing the FDA data unveiled Tuesday.
The Pfizer vaccine is already in service in Britain.
In a separate development, another Covid-19 vaccine got a largely positive report on Tuesday.
The medical journal Lancet said tests of a vaccine developed by Oxford University and AstraZeneca “suggest it is safe and about 70% effective,” the AP reported, “but questions remain about how well it may help protect those over 55 — a key concern for a vaccine that health officials hope to rely on around the world because of its low cost, availability and ease of use.”
