A Covid-19 Vaccine Shows Encouraging Signs
Developed by Pfizer and BioNTech, an experimental vaccine spurred immune responses in a small trial of humans
An experimental vaccine being developed by pharmaceutical giant Pfizer and German firm BioNTech appears safe and produced encouraging immune responses in a small trial of healthy volunteers, according to results published online Wednesday.
The study included 45 adults ages 18 to 55. Researchers randomly gave the people in the study a low, medium, or high dose of the vaccine or a placebo. Those who received a low or medium dose got a second dose three weeks later. Half of the 12 people who received the high dose developed a fever, including one person whose fever was severe. Those people were not given a second dose of the vaccine.
In 24 people who received the low or medium dose, the vaccine triggered an immune response similar to or stronger than those who have recovered from Covid-19 infections. Specifically, two doses of the vaccine produced antibodies — proteins made by the immune system in response to a foreign pathogen or vaccine. Notably, the second dose boosted the level of so-called “neutralizing” antibodies capable of blocking infection.
