AstraZeneca reported in a press release on 23/11/2020 that in the first interim analysis, AZD1222 (ChAdOx1 = Chimpanzee Adenovirus Oxford One) has an average efficacy of 70%, reaching 90%, depending on the dose. Interestingly, 90% efficacy was achieved after applying a half dose of the vaccine followed by applying a full dose approximately 30 days after the first dose. In the group in which two full doses were applied, the effectiveness was only 62%, leading to an average effectiveness of 70%.
The interim analysis detected 131 events or 131 infected volunteers, 30 of which were infected in volunteers who received two doses of AZD1222 and 101 cases of infections in the placebo group. There is no point speculating about the effect of the half dose, we need to wait for an analysis with a larger number of infected people.
According to the company, no serious adverse effects and no hospitalizations or serious cases occurred among volunteers in the vaccine group. If these data are confirmed, Fiocruz predicts that it will be possible to vaccinate 130 million Brazilians in 2021. The data has not yet been published in an international journal reviewed by other scientists.
AZD1222 can be stored, transported and handled at temperatures in the range of 2 and 8 degrees Celsius, which is great in terms of logistics. One publication in the journal The Lancet Infectious Disease on 19/11/2020, it has already brought encouraging results for the elderly, as the Oxford vaccine candidate showed good safety and efficacy results in phase 2, both for people between 18 and 55 years old and for those over 56 years old , including volunteers over 70 years old. However, this result, although encouraging, may not be representative of the older population over 70 years of age, as the study did not involve volunteers with more serious comorbidities.
The study involved the participation of 560 healthy volunteers (160 between 18 and 55 years old, 160 between 56 and 69 years old and 240 aged 70 and over). Few side effects were observed, 14 days after the first dose the production of T cells was observed and 14 days after the second dose, the presence of neutralizing antibodies against the Sars-CoV-2 virus was observed. The study was placebo-controlled, using the meningococcal conjugate vaccine (MenACWY). Without a doubt, these are good results. The University of Oxford and pharmaceutical company AstraZeneca will submit the results to Anvisa and request authorization for the emergency use of AZD1222 in Brazil.
CoronaVac: Good news!
The Butantan Institute announced on 23/11/2020 that CoronaVac's phase 3 clinical study reached the minimum number of 74 volunteers infected by Covid-19, which will allow the interim analysis, or the first analysis of the candidate's effectiveness, to be carried out. vaccine, by the independent DSMB committee (data and safety monitoring committee), which monitors the studies. Brazil is once again becoming an ideal setting for phase 3 clinical studies for vaccines against Covid-19, as we are seeing an increase in the number of people infected by Sars-CoV-2, which helps to accelerate the testing process. The first batch with 120 thousand doses of CoronaVac arrived in Brazil on 19/11/2020. The São Paulo government states that in another 40 days Butantan will receive 6 million ready-made doses and the raw materials (inputs) necessary to produce another 40 million doses.
Um article published in the medical journal The Lancet Infectious Diseases on 17/11/2020, showed that CoronaVac is safe and produces neutralizing antibodies against Sars-CoV-2 in 97% of volunteers, 28 days after application of the first dose (dose of 3 micrograms (µg) and requires two doses at an interval of 14 days). The researchers did not observe the presence of neutralizing antibodies in volunteers in the placebo group and the level of antibodies in volunteers in the vaccine group is lower than in people who have recovered from the disease. These results, evaluated by other scientists, correspond to phases 1 and 2 of clinical trials (randomized, double-blind, placebo-controlled study) and were carried out in China from April to May with 744 healthy volunteers (144 in phase 1 and 600 in phase 2) aged 18 to 59, who have never contracted Covid-19.
Sputnik V: Another one with positive results
Russia reported on 24/11/2020 that the Sputnik V vaccine candidate, developed by the Gamaleya Institute, is 95% effective in the second preliminary analysis, 21 days after the second dose of the vaccine and 42 days after the first dose. Russia had already reported on 11/11/2020 that Sputnik V was 92% effective, after the first interim analysis of phase 3, one day after applying the second dose and 21 days after application of the first dose. According to the researchers, no serious adverse events were observed.
The results were not published in an internationally circulated scientific journal and consequently were not reviewed by other scientists. The phase 3 study is being conducted in Russia and involves the participation of 40 volunteers. Russia has not released the partial analysis protocol and without data we cannot evaluate it and we need to wait for the results to be published with the necessary transparency. Sputnik V uses a platform based on two human adenoviruses Ad5 and Ad26 that cause colds and requires two doses to trigger an immune response, 21 days apart.
About the Pfizer vaccine
After the announcement that its vaccine candidate (BNT162) is 90% effective, Pfizer updated the preliminary results and announced on 18/11/2020 that its vaccine candidate is 95% effective in phase 3 studies (after two doses ), including the elderly. Without a doubt, this is great news, although the results have not yet been published in a specialized international journal and have not been evaluated by other scientists. The phase 3 study of the Pfizer/BioNTech vaccine candidate involves around 44 thousand volunteers, distributed between the vaccine group and the placebo group. The efficacy study was open with a total of 170 events, or 170 volunteers infected with Covid-19.
According to Pfizer, 9 volunteers in the placebo group had more severe forms of the disease, compared to just 1 volunteer in the vaccine group. BNT162 showed good efficacy for all age groups, races and ethnicities, and presented adverse effects in only 3,7% of volunteers after taking the second dose. Pfizer reported that its messenger RNA vaccine, despite being sensitive to heat, can be stored in special packaging, with dry ice, for around 15 days at -70 degrees Celsius, replenishing the dry ice and opening the boxes no further. than twice a day. Then, upon arriving at the application sites, the vaccines can remain in common refrigerators for up to 5 days. This is good news in terms of logistics.
The companies Pfizer and BioNTech announced that 50 million doses will be available in 2020 and plan to produce 1,3 billion doses in 2021. Pfizer and BioNTech, which invested around 2 billion dollars of their own resources in the development of vaccine, are negotiating with the Brazilian government the purchase of doses of the vaccine, which would be imported from Pfizer factories in the United States and Europe, for the first quarter of 2021. Brazil does not master this messenger RNA technology. Once approved in phase 3, the vaccine will have different prices for rich countries, middle-income countries (such as Brazil) and low-income countries. Based on these results, Pfizer and BioNTech will request emergency authorization from the FDA, the United States regulatory agency.
Brazil does not have an agreement with the Moderna vaccine (mRNA-1273)
The pharmaceutical company Moderna, based in Massachusetts, USA, announced on 16/11/2020 that its vaccine candidate (mRNA-1273) showed safety and 94,5% efficacy in a preliminary phase 3 analysis, involving 95 events, or 95 volunteers infected with Covid-19. There were 11 more serious cases, all in the placebo group. Moderna will wait for the clinical study to reach the goal of 150 events (or 150 infected volunteers) to carry out a second interim analysis and have more robust data.
In total, 30 healthy people over the age of 18 are participating in the phase 3 study. If approved and recommended for emergency use, the company promises to release 20 million doses to the US population soon and guarantees it has the capacity to production of 1 billion doses for 2021. Brazil does not have any agreement with Moderna for the purchase and distribution of mRNA-1273.
According to Moderna, mRNA-1273 can be stored at -20 degrees Celsius for 6 months, in the temperature range of 2-8 degrees Celsius for 30 days and at room temperature for just 12 hours. The required temperature ranges are different for BNT162 and mRNA-1273 because the companies use different lipid (fat) formulations to surround and protect the messenger RNA.
The issue of storage temperatures poses logistical challenges for distribution in low-income countries and hot climates. Both Pfizer and Moderna announced their results in press releases and to date, there has been no disclosure of phase 3 efficacy results published in scientific journals whose articles are reviewed by other scientists. We must wait for the completion of phase 3 studies and the publication of the results. Moderna has never put a vaccine on the market.
Vaccines only protect if people adhere to mass vaccination
Um article published by Unicamp colleagues on 26/10/2020 in Frontiers magazine, with repercussions on Science magazine, brings data that suggests that the YouTube platform contributes greatly to the dissemination of false information and increased distrust among the Brazilian population about vaccines. Among the fake news found on the platform, there are numerous claims that vaccines contain dangerous and toxic ingredients that cause illnesses or serious side effects, videos that defend individual freedom to choose whether or not to take the vaccine and various conspiracy theories.
The conclusion of the study authors is that YouTube has not acted clearly and firmly to combat the spread of Fake News and misinformation about vaccines and appears to encourage the production of this type of content, generating profit for those who produce it and for YouTube itself. through content monetization. For more details in Portuguese, click here.
The topic of vaccines must be treated as a scientific issue, not one of political ideology. There cannot be a confrontation of narratives against a public health policy that saves lives, prevents disability and improves people's quality and life expectancy. Vaccine hesitancy and the anti-vaccine movement are considered among the 10 biggest threats to global health, along with dengue fever, HIV, air pollution and climate change, non-communicable diseases such as cancer, diabetes and heart disease, the global influenza pandemic, fragile and vulnerable populations, antimicrobial resistance (to parasites, viruses, bacteria, fungi), Ebola and other high-threat pathogens and fragile health systems.
The Covid-19 pandemic has brought to the popular imagination a worrying and frightening situation in which people feel that they no longer have control over their lives and, therefore, as they do not understand scientific facts, they are more susceptible to conspiracy theories, that offer psychological relief to those who believe in them. One article published in the American Journal of Preventive Medicine suggests that a good vaccine needs to be at least around 80% effective to combat the Covid-19 pandemic. A vaccine with an efficacy of 60% to 80% will help reduce transmission of the virus, but a fundamental point is the population's high adherence to vaccines, once available. The lower the effectiveness of the vaccine, the greater the population's adherence must be to end the outbreak of a disease.
Immunity may be longer than expected
Two recent publications suggest that immunity against Sars-CoV-2, after recovery from the disease, may be longer than initially expected. One of the articles was published in the journal Nature on 12/11/2020 and shows that people recovered from Covid-19 have defense memory cells (T cells) that remain in the body, and can produce a rapid protective response in the event of reinfection.
The second article, published on 16/11/2020 on the bioRxiv platform and still unreviewed by other scientists, suggests that immunity against Covid-19 can last at least eight months after infection with Sars-CoV-2 and that the slow rate of decline observed may indicate that defense cells can last in the organism for a few years. The research was carried out with 185 men and women as volunteers, aged between 19 and 81 years old, all of whom had recovered from mild symptoms of Covid-19.
The seven groups of Covid-19 symptoms
Um article published on 31/10/2020, in the scientific journal Allergy, brings a very interesting study in which researchers from the Medical University of Vienna identified seven groups of symptoms that can accompany Covid-19. The study included interviews and blood control of 109 convalescent people who are recovering from Covid-19 and 98 healthy people, with the main objective of discovering what it would be like and how to measure good immunity after an infection with Sars-CoV-2. Scientists observed that several symptoms are related to each other and identified the seven groups below:
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Flu-like symptoms such as fever, chills, fatigue, dry cough
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Symptoms of cold, rhinitis, sneezing, dry, irritated throat and stuffy nose
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Muscle pain and joint pain
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Inflammation of the eyes and nasal mucous membranes
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Lung problems, pneumonia and shortness of breath
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Gastrointestinal problems, diarrhea, nausea and headache
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Loss of smell and taste
Even separate and independent symptoms such as dry cough, fever and loss of smell and taste should raise a warning signal. There may be overlaps between the symptoms of the different groups. The authors observed that high fever in Covid-19 may be related to a longer immunological memory, while the loss of smell and taste appears to be related to higher levels of T lymphocyte response.
Brazilians trust science more
One of the 3M global research, with results from the Annual State of Science Index (SOSI), brought interesting results about the public perception of science during the Covid-19 pandemic. The research was carried out in two stages, the first involving around 14.000 people in 14 countries, in the period August-October 2019, while the second involved participants from 11 countries, in the period July-August 2020. Each stage counted with the participation of 1.000 Brazilians and aimed to analyze the population's perception regarding the image, sustainability, importance, impact of science on society and equity in the areas of Science, Technology, Engineering and Mathematics.
In relation to the previous survey, carried out in 2019, skepticism towards science in Brazil decreased from 42% to 33%. Around 86% of Brazilians agree that science plays a fundamental role in resolving public health crises, 92% believe in science to contain the Covid-19 pandemic, 88% believe that science can improve their quality of life and 89 % believe that science needs more funding.
With the pandemic, the percentage of Brazilians who defend science increased to 73%. Around 65% of Brazilians defend racial equality in society and the guarantee that minorities have access to education in the areas of Science, Technology, Engineering and Mathematics (STEM). A very high percentage, 89-92% of Brazilians, believe that governments should be more involved in solving problems such as combating Covid-19, offering free access to public healthcare, improving air quality in cities, providing access to energy clean and renewable, invest in infrastructure, encourage education in science, technology, engineering and mathematics and reduce ocean pollution.
In time: About the BCG vaccine
On 16/11/2020, Fiocruz started phase 3 studies with the BCG (Bacillus Calmette-Guérin) vaccine in Rio de Janeiro, with around 1.000 health volunteers. BCG is used to prevent tuberculosis and the study is called Brace Trial Brazil (BTB) and its main objective is to reduce the impact of Covid-19 on healthcare professionals on the front line of fighting the disease, protecting or mitigating the symptoms.
Note: This text does not necessarily reflect the opinion of Unicamp.
