SAO PAULO, SP (FOLHAPRESS) – A vaccine against Covid-19 developed by the Beijing Biological Products Institute, linked to Chinese state pharmaceutical Sinopharm, had promising results from initial clinical tests (phases 1 and 2) released on Thursday ( 15) in the scientific journal The Lancet Infectious Diseases.
According to the study, signed by Chinese researchers from several research institutions in that country, the vaccine called BBIBP-CorV, still in development, was able to generate neutralizing antibodies to the Sars-CoV-2 coronavirus even in people over 60 years old , those with the highest risk of death from Covid-19.
In older participants, however, the immune response took longer to detect than in those between the ages of 18 and 59 – according to the results, there was an average delay of about 14 days before the reaction was recorded. The levels of antibodies found in these people were also lower than in younger people.
It is not yet possible to say whether the vaccine protects against infection by the new coronavirus – only a phase 3 clinical test, carried out with thousands of participants followed for several months, can attest to the substance’s effectiveness and demonstrate the level of protection it provides.
A phase 3 clinical study (the last phase of testing prior to the release of a drug or vaccine) is to be carried out in Argentina with approximately 3,000 healthy participants aged 18 to 85 years. A record of the test was filed at the end of September on the ClinicalTrials.gov page, maintained by the United States National Institutes of Health (NIH). A similar survey, involving about 15 thousand people, is underway in the United Arab Emirates.
According to Anvisa (National Health Surveillance Agency), there is no application for registration or research with the Sinopharm vaccine in Brazil so far.
More than 600 healthy people over the age of 18 participated in the two initial phases, designed to verify the safety of the vaccine and the doses necessary to generate an immune response. The study was randomized and included a control group, which received a dose of placebo (substance without effect) in place of the vaccine.
The researchers concluded that the best result was achieved with the application of two doses with an interval of 21 or 28 days between them. 42 days after the first vaccination, all participants had an immunological response against the virus detected. On average, participants took 28 days to develop neutralizing antibodies to the new coronavirus.
The vaccine also proved to be safe, say the scientists. The most common reactions were pain at the application site and fever. All effects were mild or moderate in intensity.
The Sinopharm vaccine is based on the inactivated virus, unable to start the infection, but sufficient to generate an immune response. Another Chinese vaccine, CoronaVac, developed by Sinovac and tested in the state of São Paulo by the Butantan Institute, uses the same method to generate an immune reaction in the human body.
Inactivated virus vaccines are among the easiest to handle and transport because they have storage temperatures closer to room temperature. CoronaVac, for example, can be stored in a refrigerator (2ºC to 8ºC) and can withstand up to 27 days at 37ºC, according to the Butantan Institute. This characteristic makes them the most suitable for a country like Brazil, with a warmer climate and long distances.
The development of Sinopharm’s immunizer and the first tests on monkeys were described in an article published in August in the scientific journal Cell. The results show that the immunizer was safe and efficient to prevent infection by Sars-Cov-2 in monkeys.
Until this Thursday (15), more than 40 of the vaccines under development go through one of the phases of clinical tests, according to WHO (World Health Organization). Another 156 substances are in the preclinical stages. According to experts, several different types of immunizers will be needed to contain the current pandemic. Vaccines use different methods to generate protection and must be of varying effectiveness when used on different groups of people.