KEY POINTS

  • The vaccine is known as BNT162b1 and is being developed in conjunction with BioNTech SE
  • The results are based on the first 45 people enrolled in the clinical trial since late April
  • The company said those who received the vaccine produced more antibodies than someone who had recovered from a coronavirus infection

Preliminary results from a clinical trial of the BNT162b1 messenger RNA vaccine indicate the vaccine triggers a significant immune response in recipients, Pfizer (PFE) and BioNTech SE (BNTX) announced Wednesday.

The vaccine is among 150 currently under evaluation worldwide. Though there is no guarantee a safe and effective vaccine ever will be developed, several candidates have been labeled promising.

“We are encouraged by the clinical data of BNT162b1, one of four mRNA constructs we are evaluating clinically, and for which we have positive, preliminary, topline findings,” Pfizer Senior Vice President and head of Vaccine Research and Development Kathrin U. Jansen said in a press release.

The phase 1/2 U.S. clinical trial began enrolling 7,600 participants at the end of April. The first batch of 45 subjects were broken into three groups: 24 individuals who received the vaccine in two doses, 21 days apart; 12 subjects who received a single, higher dose of the vaccine, and a third group that was given a placebo.

Those who received the vaccine, whether one dose or two, had more antibodies in their blood after 21 days than people who had recovered from coronavirus infections, the companies said.

Adverse reactions included a low-grade fever, primarily after the second dose, and pain at the injection site.

A global phase 2b/3 safety and efficacy trial was expected to begin later this month and involve as many as 30,000 healthy participants.

Pfizer and BioNTech said they expect to have 100 million doses on hand by the end of 2020, and more than 1.2 billion doses by the end of 2021 to distribute worldwide.

Moderna’s mRNA-1273 also has shown promising preliminary results, and Johnson & Johnson has accelerated its trials of Ad26.COV2-S, which involves recombinant RNA. Novavax ( NVAX ) has said NVX-CoV2373 showed promise in preclinical trials.

Food and Drug Administration Commissioner Stephen Hahn told a Senate panel Tuesday his agency will not be pressured to approve an ineffective or dangerous vaccine. He said any vaccine will need to meet certain standards and will need to prevent the disease or lessen the severity in at least half of those who receive it.

Pfizer traded 3.21% higher Tuesday at $33.75 while BioNTech closed 3.9% lower at $64.14.