the pharmaceutical company Pfizer announced that its COVID-19 vaccine candidate, which was already showing good results in June, is more than 90% effective in preventing the disease, according to initial data from the phase 3 study. The efficacy rate is data that represents how many people received the vaccine and did not get sick. With the rate being 90%, this means that 9 out of 10 patients who participated in the trial are not getting sick, indicating that the Pfizer vaccine is generating an immune response. 26e2k
Pfizer vaccine must be at least 50% effective 5y4y17
A FDA, a regulatory agency in the United States, has already announced that any vaccine must prove 50% effective before being released, and that companies testing vaccines must track 50% of participants for two months to record side effects. Pfizer believes and hopes to reach this mark by the end of this month, as according to the pharmaceutical company, no serious cases of COVID-19 have been recorded among participants so far.
The American regulatory agency also requires that candidate vaccines in the country be studied in at least 30 people, and the Pfizer vaccine has already been applied to more than 43.538 participants from 4 countries, including Brazil. The vaccine effectiveness data was released after 94 of the participants had contracted the new coronavirus, with the company not disclosing how many of those cases took the vaccine or the placebo.
Pfizer plans to continue testing until 164 participants have contracted COVID-19, to confirm the rate of effectiveness. For now, the published data have not been checked by other scientists, an important step for publication in scientific journals. According to the company, the data will be checked when the entire study is finished.
The 3 Phases of COVID-19 Vaccine Testing: How They Work 452l4z
Vaccine tests are carried out so that scientists try to identify serious adverse effects and whether the immunization is effective, which means inducing a response from the body's defense system. Phase 1 has tests that usually involve dozens of volunteers, and with each subsequent phase the number of volunteers increases, reaching hundreds in phase 2 and thousands in phase 3.
Before human trials begin, vaccines are tested on animals – typically on mice and then on monkeys. The various testing phases are usually conducted separately, but because of the urgency of the new coronavirus pandemic, several studies have carried out more than one step at the same time, which in some cases leads to questions about the real safety of these vaccines.
Source: G1
