Pfizer’s experimental coronavirus vaccine, which is based on RNA gene technology, has shown promising results in an early trial.
According to a news release from the journal Nature, the vaccine candidate, called BNT162b1, “elicited a robust immune response in participants, which increased with dose level and with a second dose.”
Dr. Judith Absalon of Pfizer, who led the early clinical phase I/II trial, said BNT162b1 is based on messenger RNA, a genetic code that helps kick-start the immune response when the body encounters the novel coronavirus.
The journal noted, “Vaccine development strategies focused on RNA are generally considered safe and have facilitated the rapid development of vaccines against SARS-CoV-2.”
The trial involved 45 healthy adults aged between 18 and 55. They were divided into two groups, with one group received a low, medium, or high dose of the experimental vaccine, while the other a placebo.
“The vaccine elicited a robust immune response in participants,” according to the results. The authors reported that the higher the dose, the stronger the response.
Getting a second “booster” dose also increased the immune system response.
The journal mentioned that in participants who got the vaccine, “levels of [coronavirus-] neutralizing antibodies were 1.9 to 4.6 times higher than those in patients recovering from SARS-CoV-2.”
However, Dr. Absalon and her team stressed that Phase III clinical trials are still needed to confirm the safety and efficacy of the vaccine.
The journal also mentioned that the shot was “generally well-tolerated” but some participants experienced side effects such as fatigue, headache, fever, and sleep issues, and soreness at the injection site. “Those tended to clear up within a week of vaccination,” the researchers said.
Infectious disease expert Dr. Amesh Adalja of the Johns Hopkins Center for Health Security in Baltimore said, “The study provides more evidence of mRNA candidate COVID vaccines do induce neutralizing antibodies after two doses.”
Dr. Adalja explained that there are “multiple” experimental vaccines that are based on RNA technology, suggesting that they could spark a strong immune response in people. “What remains to be seen is what these antibodies translate to when a vaccinated individual is faced with the wild virus,” Dr. Adalja added. “Until we see phase 3 clinical data, it is still an extrapolation to understand how effective these vaccines will be in the real world.”
