Pfizer stock also gained, rising 4.4% to $34.13.
It said the amount of antibodies produced in participants after they received two shots of the vaccine candidate was greater than that reported in patients receiving convalescent plasma from recovered COVID-19 patients.
According to Pfizer, local reactions and systemic events after injection with 10 µg and 30 µg of BNT162b1 were "dose-dependent, generally mild to moderate, and transient".
Initial clinical data for one of these candidates, BNT162b1, demonstrated that the experimental vaccine was both well tolerated and generated dose-dependant immunogenicity.
Hong Kong's Hang Seng index jumped 1.53 percent to 22:46 Eastern time (03:46 GMT) on the first day of trading after the entry into force of the law on national security passed by the National Congress of China on Tuesday.
Early-stage human trials of vaccines are created to measure certain antibodies and other immune markers in the blood as an indicator of the body's readiness to fight an infection that then requires further validation.
The pharmaceutical industry is eager to launch larger follow-up trials to see how vaccinated participants react to real infections over longer periods.
There are more than 140 vaccines now being developed in a bid to get out of the crisis.
Some caveats required: It's promising news, but this is the first clinical data on this specific vaccine, and it hasn't been through the process of peer review yet.
The treatment is not yet approved for distribution but if it is, Pfizer aims to produce up to 100 million doses by the end of the year and potentially more than 1.2 billion doses through 2021.
The Mainz-based company is using the so-called messenger RNA approach, like unlisted domestic rival CureVac and Moderna.
Updates on the progress in various Covid-19 vaccine programs are being closely watched by investors, and have been partly responsible for Wall Street's recent rally.
Biotech investors Thomas and Andreas Struengmann, who sold their generic drugs business Hexal to Novartis in 2005, are major shareholders of BioNTech.