It's not just for you, but for everyone around you, it's for understanding, empathy, altruism, respect for life e social responsability. The vAction and non-pharmacological measures to overcome the pandemic must be seen as a collective pact for life. Vaccinated people have a lower chance of becoming infected and just over 90% of infected cases in the world occur among the unvaccinated.
A study, still in the form of preprint, published on 25/08/2021 showed that vaccinated people, when infected, têThey generally have a lower viral load and stay with the virus for a shorter period of time, compared to unvaccinated people who are infected with Sars-Cov-2. If people recover faster, they transmit the virus for less time and this reduces the transmission rate of the disease.
Studies in the real world with the Pfizer and AstraZeneca vaccines show that vaccination reduces household transmission by up to 50%, including just with the first dose of either of the two vaccines, that is, people living in the same house, when not vaccinated, becoming infected , contaminate twice as many people in the same house. This can be extrapolated to other covid-19 vaccines as well.
Um another study published on 28/09/2021 in the journal PLOS Medicine, conducted by the University of Oxford and the United Kingdom's National Institute for Health Research, involving 273.618 patients, showed that 37% of people recovered from covid-19 remain with, at least least one symptom of the disease for up to six months. According to the study, theOlder people and men have more symptoms such as breathing difficulties and cognitive problems, while young people and women have more headaches, abdominal symptoms, anxiety or depression.
It will be necessary to vaccinate children and adolescents
To control the pandemic, we will need to vaccinate our teenagers aged 12-17 and, in the near future, our children aged 5-11. This will be fundamental in this process of blocking the transmission and circulation of the virus. Children can also die from covid, they can have serious sequelae and long Covid-19, with symptoms that can last for months. Infected children and adolescents can also transmit the disease, although less so, as vaccinated people have a lower viral load, transmit the virus less, have milder conditions and recover more quickly from the disease as the body eliminates the virus more quickly.
Another important point is that Science is showing that evolutionary capacity of the virus is lower in vaccinated people, which means that the virus mutates less in vaccinated people, compared to the greater number of mutations that occur in vaccinated people. There are many advantages to taking vaccines, vaccinated people have less chance of being infected, more likely to have milder cases if infected and transmit the virus less when infected.
Our children, young people and teenagers need to return to school safely, without guilt and without fear. There are many actors involved in the return to school, affecting not only family members, but school employees, teachers, bus drivers, van drivers, in short, everyone in the daily school life of our children and teenagers.
The vaccine is our best strategy to combat the disease, reduce the spread of the virus and contagion, reduce serious cases with hospitalization and death, but they are just one of the layers of protection. Even if we are vaccinated, we need other protection tools such as non-pharmacological measures, the use of masks, hand hygiene habits, avoiding crowds and closed spaces with little ventilation.
The benefits of vaccination are much greater than any risks or adverse effects. The vaccines are safe, effective and continue to be evaluated in the pharmacovigilance phase for the possibility of possible adverse events occurring. Most of the time, there is only a temporal relationship, not a cause and effect relationship between the effect observed with vaccination. The vaccination campaign must follow scientific evidence and remain firm in its purpose of achieving broad vaccination coverage.
About hybrid immunity - 1a part
Um article published on 25/06/2021 in the prestigious scientific journal Science, suggests that people who have so-called hybrid immunity would be more protected against new variants of the Sars-CoV-2 virus. But who would own such hybrid immunity, considered so special? In principle, people who were infected by one of the Sars-CoV-2 variants, but who subsequently took at least one dose of vaccines based on the messenger RNA platform (but perhaps this is true for all vaccines).
It would be a combination of natural immunity acquired through infection, with immunity generated by the production of neutralizing antibodies induced by vaccines. In summary, neutralizing antibody titers against the Beta variant after vaccination of people recovered from Covid-19 were approximately 100 times higher than in people infected with the same variant but not vaccinated and about 25 times higher than in vaccinated people , but never infected by the virus.
A hybrid immunity proposal is based on a supposed evolution of neutralizing antibodies that are produced after natural infection. With vaccination, the new antibodies would be much more numerous and potent and would be more resistant to the natural evolution of the virus. In combination, these studies suggest that in people who have already been infected, subsequent vaccination greatly reduces the risk of reinfection. There is a greater amount of antibodies compared to natural infection and homologous vaccination.
About hybrid immunity - 2a part
In this text, we will consider that natural immunity is the immunological protection obtained as a response to Sars-Cov-2 infection. And let's consider the term immunity conferred by vaccines, as the immune protection response after taking any of the vaccines against Covid-19. In these cases, immunological memory is the source of protective immunity, although natural immunity and immunity generated by vaccines in response to Sars-CoV-2 are actually different paths to protection conferred by the immune system.
We are learning that the potency or effectiveness of neutralizing antibodies in combating new variants of concern reduces over time for both natural immunity and vaccine-generated immunity. This is where the concept of hybrid immunity comes in, which is considered a more robust immunity that develops in people with natural immunity acquired after Covid-19 infection, who are subsequently vaccinated. There is a protective response from memory B cells (which produce antibodies) and more robust T cells, resulting from a combination of natural immunity and vaccine-induced immunity. It is as if the quality and robustness of these memory B cells increases with exposure to vaccine antigens. The virus is trying to adapt to the host, which is us humans. In this process, the virus undergoes random mutations with the aim of escaping the protective response conferred by vaccines, as a pressure from natural selection to escape the immunity generated by the host.
Natural infection with Sars-CoV-2 generates high-quality memory B cells after the original infection, but which would increase in quality and quantity after the application of vaccines, offering broader cross-protection against new variants. The immune system of people recovered from Covid-19 identifies exposure to vaccine antigens as a more serious threat to be combatted. The hybrid immunity response was observed for people recovered from both mild and severe cases of Covid-19.
Interchangeability - The combination of different vaccine platforms, or heterologous vaccination, can apparently work as in the concept of hybrid immunity and lead to more robust and consistent protective responses.
Second dose of Janssen increases protection against covid-19
Johnson & Johnson had described in a study published on 02/09/2021, that the Ad26.COV2.S vaccine induced significant protection against COVID-19 up to eight months after the initial vaccination. Recent data from ENSEMBLE 2 study, show that a booster dose of the Janssen vaccine (Ad26.COV2.S) administered 2 months after a single dose of the same vaccine increases protection by 94%, leading to an increase of approximately 4 to 6 times in the level of antibodies, 14 days after the vaccine booster. If the booster dose is administered after 6 months of the single dose, there is a 12-fold increase in the level of antibodies, regardless of age.
Around 14 days after the booster dose, the protection observed was 100% against severe cases and 75% protection against symptomatic Covid. Protection against mild to moderate disease is lower and people can still become infected and transmit the disease. The study included 390.000 people who received the Johnson & Johnson vaccine and the results were compared with a placebo group of about 1,52 million unvaccinated people, conducted from March to the end of July 2021. Janssen had already published on 16/09/2021 a study showing that the effectiveness against serious cases of Covid-19 in the real world, in places with the Delta variant circulating, is 79% for infections and 81% for hospitalizations, 14 days after the single dose.
ABOUT NEW VACCINES
- Fiocruz may produce a new vaccine against
AOPan-American Health Organization (PAHO) announced on 21/09/2021, the choice of the Institute of Technology in Immunobiologicals (Bio-Manguinhos) of Fiocruz and the biopharmaceutical company Sinergium Biotech, in Argentina, as centers in Latin America to produce a new vaccine against Covid-19, with the aim of expanding access to vaccines in the region. The vaccine candidate is based on messenger RNA (mRNA) technology, expressing the Spike protein, as in the Pfizer and Moderna vaccines, but also the virus's N protein (nucleocapsid protein, which is inside the virus), with the objective of expanding the immune protection response. In addition to Fiocruz, around thirty Latin American companies and scientific institutions participated in a global WHO call. If this venture is successful, it will be a gigantic scientific achievement, as it will allow Brazil to master technological knowledge for the development of future vaccines to treat other diseases. It's Science that calls, you know?
- Butanvac test results
Preliminary results published on the platform MedRxiv preprints on 22/09/2021, involving phase 1 clinical studies conducted in Thailand, show that the Butanvac vaccine candidate (called NDV-HXP-S) is safe and presents a strong immunogenicity response. Butanvac is also being tested here in Brazil and Vietnam. The clinical study involved the participation of 210 volunteers (82 men and 128 women between 18 and 59 years old), was randomized and controlled by a placebo group. Each volunteer took two doses 28 days apart and the adverse effects were considered mild. NDV-HXP-S will be tested on a larger number of participants in phase 2 and if everything goes well, it will enter phase 3 where its effectiveness will be verified. Phase 1 studies verified the safety of NDV-HXP-S and dose selection showed that the 3 microgram and 3 microgram plus adjuvant formulations were selected for evaluation in phase 2. Read more details about Butanvac.
About the batches collected from Coronavac
Butantan published on 28/09/2021, note advertising the collection of approximately 8 million doses of CoronaVac, as advised by Anvisa. Anvisa ordered the recall of these doses, as they were bottled in a Sinovac factory not inspected by the agency, which violates the terms of the Temporary Authorization for Emergency Use of the CoronaVac vaccine. Butantan analyzed the quality and integrity of the vaccines, found no problems and has been monitoring the adverse effects reported by people who took doses from these batches and concluded that the safety profile is the same as other batches bottled in factories approved by Anvisa. Butantan advises that there is no need for revaccination and states that the effectiveness of the vaccine does not change. According to Anvisa, the banned lots will be destroyed or rendered unusable.
More information about Anvisa's position on this matter, as well as the impacted lots. If you have any questions, people should call SAC Butantan, number 0800-701-2850.
STUDIES ON THE PFIZER VACCINE
- Include a booster dose in the leaflet
Anvisa received a order from Pfizer to include the booster dose of the Comirnaty vaccine in vaccine leaflet. Today, the leaflet contains two doses and is recommended for individuals aged 12 years and over. Pfizer's request includes safety and efficacy data for the application of a booster dose and concerns homologous vaccination, to be applied to people who have received two doses of the Comirnaty vaccine, with the booster being applied with the same vaccine, 6 months after the second dose.
- It is safe and immunogenic for children aged 5 to 11 years
Preliminary results of a Phase II/III clinical study with approximately 4.500 children aged between 6 months and 11 years in the United States, Finland, Poland and Spain, suggest that Pfizer's Comirnaty vaccine is safe and induces a robust antibody production response in children aged 5 to 11. The study was divided into 3 groups by age group: (1) 6 months to 2 years of age; (2) 2 to 5 years of age and (3) 5 to 11 years of age. The approximately 2.268 children aged 5 to 11 who participated in the study received two injections with a lower dose, 10 micrograms each dose (the Pfizer vaccine leaflet states for those over 12 years of age, a dose of 30 micrograms for each dose). The aim of the study was to evaluate the amount of neutralizing antibodies produced in children compared to the amount observed in previous studies in adults. The vaccine showed an excellent safety profile, with mild adverse effects compared to those observed in volunteers aged 16 to 25 years.
- Booster dose increases antibodies in those who took Coronavac
In Uruguay, just over 74% of the population has already taken 2 doses of vaccines against Covid-19. A preliminary study, presented at a press conference, conducted by scientists from the Pasteur Institute (IP) in Montevideo and the University of the Republic (Udelar) shows that the application of a booster dose of the Pfizer vaccine increased the level of antibodies in up to 20 times people immunized with two doses of Coronavac. The study evaluated the evolution of levels of specific antibodies against the coronavirus and found that, 18 days after the booster dose with the Pfizer vaccine, participants had an increase of around 20 times in the level of antibodies compared to the level of antibodies observed 18 days after the second dose of CoronaVac. Science is still seeking to understand the correlate of protection with the aim of determining what level of neutralizing antibodies is associated with the effectiveness of vaccines against Covid. Although the duration of protection is not yet known, these are very important results.
Observation: The articles published do not reflect the opinion of Jornal da Unicamp. Its publication aims to stimulate the debate of ideas in the scientific, cultural and social spheres.
