Another new coronavirus candidate has shown encouraging results in phase 1/2 trials in the United States,media BGR reported. Pfizer has partnered with BioNTech to develop an experimental mRNA drug that has been shown in trials to provide neutralizing antibodies that block the new coronavirus and prevent infection. According to data published by the two companies, including a complete study of clinical trials, various doses of experimental drugs can cause a better immune response than was observed in COVID-19 survivors.
BNT162b1 is the most advanced of the four candidates in BioNTech’s BNT162 mRNA vaccine program. Each vaccine uses a unique combination of mRNAs and target antigens, the two companies explained in a press release. The researchers divided 45 volunteers between the ages of 18 and 55 into three groups of 12 people, and nine people in the fourth group were compared to a placebo. Two groups received two doses of 10 micrograms or 30 micrograms of BNT162b1, 21 days apart, one of which received a single dose of 100 micrograms of mRNA vaccine. The placebo group was also vaccinated twice.
7 days after vaccination of the second shot of 10 ?g or 30 ?g — the 28th day after vaccination, neutralizing the highest antibodies. Antibody titer was 1.8 times higher and 2.8 times higher than antibodies in the recovery serum, respectively. After the second injection on the 28th day, the researchers observed an increase in concentrations of RBD-combined IgG in the blood — eight times higher and 46.3 times higher than the IgG concentrations in the serum of the COVID-19 survivor group, respectively. The concentration of IgG and neutral titer of RBD-binding were also higher than the recovery period serum after 21 days in the group receiving the highest single-dose course of treatment, which was 3 times higher and 0.35 times higher, respectively.
The 12 participants were not given a second dose because more patients had local reactions and systemic events after a single dose of 100 ?g, but did not exhibit better immunogenicity than the 30?g group. One of the volunteers, 100 sg, showed severe pain at the injection site. The most common side effect is mild to moderate pain after injection. People who received a dose of 10 ?g or 30 ?g were more likely to develop low-level fever after the second dose. 8.3% of the 10 micrograms group and 75% of the 30 micrograms group showed a fever of 38 degrees C.
Pfizer and BioNTech published a full study detailing their findings in a preprinted form of medRxiv, which will present the paper to a possible peer-reviewed journal. The paper says current observations suggest that “the dose levels of this candidate vaccine with good tolerance and immunogenicity may be between 10 micrograms and 30 micrograms”.
Pfizer and BioNTech plan to begin a large-scale global phase 2/3 trial in late July, awaiting approval, that will include up to 30,000 healthy participants. If all goes well, the two companies hope to produce 100 million doses of the vaccine by the end of the year and as many as 1.2 billion by 2021.