Pfizer and BioNTech have started a clinical trial that provides for the application of a third dose of the covid-19 vaccine developed by them in people already inoculated. The goal is to see if the measure reinforces protection against new variants of the coronavirus, as announced on Thursday (25).
According to the pharmaceutical companies, this booster dose will be administered at an interval between six and 12 months after the application of the first two, making it possible to verify the effects of a third injection on the immunity of the study participants. The researchers want to know whether the antibodies already acquired will be able to fight the Sars-CoV-2 mutations identified in recent months.
The test, which takes place even without companies noticing any evidence that the current vaccine fails to protect against the newly discovered variants, will also allow assessing the body’s safety and tolerability to a new application of the immunizer, but will not measure the effectiveness of the vaccine already proven in previous tests.
For this new study, American volunteers who participated in phase 1 in the original test, which took place last year, will be recruited. They will receive an extra dose of 30 micrograms. “This reinforcement study is critical to understanding the safety of a third dose and the effectiveness against circulating strains,” commented Pfizer executive director Albert Bourla.
Moderna also assesses booster dose
Another pharmacist that can test the use of a third dose of the vaccine against the new coronavirus is Moderna, also with the purpose of verifying protection against mutations of the virus already identified.
The company also revealed to have produced an updated version of its immunizer, called mRNA-1273.351, whose effectiveness against the South African variant, known as B.1.351, it intends to test.
A modified version of the vaccine, for specific protection against new strains, is also not ruled out by companies Pfizer and BioNTech.