Pfizer Inc. and BioNTech SE have announced a new clinical trial that will test the ability of four experimental messenger RNA (mRNA) vaccine candidates to prevent infection with SARS-CoV-2, the virus that causes COVID-19. The trial in the United States will be at the NYU Grossman School of Medicine and the University of Maryland.
In Germany — where BioNTech has its headquarters — the companies launched a similar trial with the vaccine (called BNT162) last month, dosing the first subjects in the German trial in late April.
The vaccines being studied are all part of a class called mRNA vaccines. These types of vaccines are made up of viral messenger RNA, genetic material similar to DNA that instructs cells to make new proteins.
A successful vaccine teaches the immune system to recognize microbial invaders for future encounters. Two of the study vaccines contain viral mRNA with instructions for the "spike protein." This protein is used by SARS-CoV-2 to attach to human cell surfaces and invade human cells. The other two vaccines contain viral mRNA with instructions for receptor-binding domains, regions of the spikes that help attach the virus to human cells. By including the viral instructions for the spike protein and receptor-binding domains, the vaccines could allow our bodies to recognize and destroy important viral components early.
The initial phase of the study will test safety, dosing and the number of doses needed by midsummer with 360 healthy participants. Patients will receive either 1 or 2 doses of one of the vaccines or a placebo (saline solution). Participants will be split into two age groups: 18 to 65 years old and 65 to 85 years old. Younger adults will be tested first, and when there is initial evidence of safety, older adults will be tested.
Mark J. Mulligan, M.D., is the director of the Division of Infectious Diseases and Immunology and the Vaccine Center at NYU Langone Health. "Vaccines have always been our most effective weapons to protect the health of the public from infectious disease threats, which is why it's so important to study these candidates closely," he said in a press release. Further phases of the trial will determine if these vaccines will be effective in the global fight against COVID-19.