The anti-vaccine movement is criminal and a serious and growing threat to global health. There is indeed an anti-vaccine movement growing in Brazil, so we cannot ignore it. An article published on 10/09/2020 in magazine The Lancet involving 284.381 people in 149 countries, shows that the anti-vaccine movement, religious extremism, political instability, populism, fake news and issues such as safety can undermine mass vaccination campaigns and confidence in vaccines in countries with these problems. Vaccines, basic sanitation, treated sewage and drinking water are our best public health tools.
Vaccines are responsible for increasing our life expectancy, were mainly responsible for reducing infant mortality and are a milestone in the history of human health. Vaccines save about 3 million people a year, or 5 people every minute. In Brazil in the 1950s, around 10% of children died before their first five years of life. Diseases such as measles, polio, chickenpox, mumps, rubella, tetanus, diphtheria, rotavirus, whooping cough were controlled. Smallpox was eradicated in 1980.
According to data from the National Immunization Program for 2019, after 20 years, Brazil has seen a drop in vaccination coverage for children and has not reached the target for the main vaccines recommended for children up to 2 years of age. Data National Immunization System (Datasus base), show that the dropout rate for nine vaccines in Brazil, such as meningococcal C (two doses), MMR (two doses against measles, rubella, mumps) and polio (three doses), has grown by around 48% in the last five years. Vaccination coverage against polio in the country was 96,5% in 2012 and was 86,3% in 2018, with the 2019 vaccination rate being the worst since 2000.
A vaccine eliminated measles of the Brazilian population, but it was reintroduced in the country and in 2019 we had around 18 thousand cases in 526 municipalities in 23 Federation Units, with 15 deaths. The dropout statistics also include children who took an initial dose of a certain vaccine, but do not return to take the following doses. These data are worrying and highlight the need for that we will need intense mobilization to expand vaccination coverage for Covid-19 in Brazil.
The drop in coverage may have several reasons, from underfunding of public health priorities, logistical issues such as acquisition and distribution, and lack of population awareness campaigns. This reduction in vaccination coverage may also have been influenced by the success of the national immunization program in the country, as we eliminated some of the main diseases and the difficulty in accessing essential health services for families.
We need to have quality scientific information available, didactic, accessible, with clear language to combat anti-vaccine movement and growing denialism in the country, especially at this time of political polarization. We need people to spread the correct messages and information about the importance of vaccination against Covid-19. Among the reasons that have been raised on social media by anti-vaccine groups are conspiracy theories, DNA alterations, Bill Gates, chips in vaccines, that they cause autism, contain mercury, aborted fetuses, the danger and ineffectiveness of vaccines and many people are reading these lies.
We need to start a campaign to engage and prepare the Brazilian population and the SUS infrastructure for fight this anti-vaccine movement, don't let it grow. It is necessary to encourage and deliver a clear message to the Brazilian population about the need and importance of mass vaccination against Covid-19. We have to act on several fronts, the task will be complex, complicatedWe cannot delay in acting if we want to prevent anti-vaccine groups from spreading lies and fake news on social media about vaccines against the new coronavirus. The expansion of conspiracy theories about vaccination is also related to communication problems between researchers, scientists, doctors and other health professionals with society.
The good news :Nnine vaccine candidates in the last phase of testing
According to the World Health Organization (WHO), we have 192 registered vaccine candidates, 146 in pre-clinical trials, 37 in phases 1 and 2 and 9 in phase 3. Almost all required two doses in phase 2 trials to induce a response of antibodies, some of which also induced a T cell response.
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University of Oxford/AstraZeneca (UK) – AZD1222 – Non-replicating viral vector, attenuated chimpanzee adenovirus, two doses 28 days apart
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Janssen Pharmaceutical Companies (USA) – AD26CoV-S1 – Non-replicating viral vector, human adenovirus, two doses 56 days apart
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CanSino Biologics Inc./Beijing Institute of Biotechnology (China) – AD5-nCoV – Non-replicating viral vector, Ad5 human adenovirus, attenuated, 1 dose
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Gamaleya Research Institute (Russia) – Sputnik V – Non-replicating viral vector, human adenovirus, two vectors, one dose of rAd26-S and one dose of rAd5-S after an interval of 21 days.
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Sinovac (China) – CoronaVac – Inactivated virus, two doses 14 days apart
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Sinopharm/Wuhan Institute of Biological Products (China) – Inactivated virus, two doses 14 or 21 days apart
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Sinopharm/Beijing Institute of Biological Products (China) – Inactivated virus, two doses 14 or 21 days apart
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Moderna/National Institute of Allergy and Infectious Diseases (USA) – mRNA-1273 – messenger RNA, two doses 28 days apart
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Pfizer/BioNTech/Fosun Pharma (USA and Germany) – BNT162 – messenger RNA, two doses 28 days apart
Although it is not yet clear what the main marker of protection against Covid-19 is, the phase 3 clinical trial aims to evaluate the effectiveness in preventing infection and preventing cases of Covid-19 in the vaccinated population or making the disease milder. . An ideal vaccine would be one that is effective in just one dose, inducing sterilizing immunity, immunizing the majority of those inoculated, producing long-lasting immunity, with little reactogenicity and few immediate or late side effects, ease of storage, distribution and application. That does not require a cold chain with very low temperatures and that is accessible, available and cheap.
Once all testing phases are complete, what are the next steps?
We will certainly have more than one approved vaccine for Covid-19. ANVISA will also have to work on an accelerated basis to register vaccines approved in phase 3, maintaining the necessary scientific rigor. But there is a real possibility that we will need vaccines in at least two doses. We are 212 million Brazilians, if we have 80% adherence, we will vaccinate around 170 million people. If the vaccine offers protection in a single dose, we will need 170 million doses, but if it requires two doses, we will need 340 million doses. And as this will be the largest vaccination program in the history of humanity, we can expect some logistical challenges, in addition to hoping that people who take the first dose will return for the second dose and return for a possible third dose, especially groups of elderly people and people with comorbidities, with a more deficient and less robust immune system in terms of vaccine response. People will have to take time off work, waste time in long lines, all twice. And they will possibly experience unpleasant side effects, such as fever, pain and swelling at the injection site, all twice, in a short period of time.
It is necessary to produce millions of doses and we will need to purchase inputs and adjuvants from foreign markets, as Brazil does not produce them here. From the acquisition of the Active Pharmaceutical Ingredient (IFA) and adjuvants, the stages of formulation, quality control, packaging and labeling begin. Then comes the storage stage, the cold chain, transportation and movement, distribution and administration. Personal protective equipment is also necessary for handling vaccines in cold rooms, so that batches of doses can be properly packaged and shipped. And after that we will need syringes, needles, glass vials, lids for the vials, packaging to store the vaccine vials, gloves, all disposable materials. A lot of hospital waste will be generated and great care will be needed when disposing of it. There are many challenges, in addition to hoping for good efficacy, sustainability and duration of vaccine protection.
The stability of vaccines depends on storage temperature. Vaccines may lose effectiveness due to temperature variations during batch production, storage and transportation. Vaccines are very sensitive products and heat, cold and ambient light can weaken a vaccine depending on the formulation. Some of them can be stored at temperatures around 0° to 10°C, but it is necessary to think about cold chain strategies, so that adequate storage is maintained at all stages of production, storage, transport and distribution until reaching to the health center or application site. As mRNA molecules are very sensitive, vaccine candidates from the American company Moderna and Pfizer / BioNTech can bring logistical challenges, as they will certainly need freezers with temperatures of -20 degrees Celsius a -70 degrees Celsius, which is common in university laboratories and research institutes, but not in SUS health centers. Inactivated virus vaccines, such as the one from China's Sinovac, can perhaps be stored in common refrigerators, but it is necessary to take care of their stability and maintain a low temperature, especially in places with unstable electricity supply.
Brazil is a gigantic country, with people spread out in very remote places, so vaccines have to arrive by land, water and air. Some carriers like UPS and DHL are gearing up and airports need to do the same. We will need good stocks of dry ice to keep the temperature low to ensure that the doses are not compromised when transported to places without electricity. There can be no mistakes along this path, as any exposure to too much light or inappropriate temperatures could harm the quality of the vaccines, leading to a loss of potency, which would be a huge disservice.
And, of course, the professionals responsible for the applications must receive training, instructions for packaging, opening and handling the vials with the vaccines.
Brazil has a lot of experience in mass vaccination campaigns, the National Immunization Program (PNI) works very well and we can overcome these barriers. But without a doubt, great coordination between various segments of civil society will be necessary. The vaccine candidates are in the hands of scientists, but what about vaccination? In Brazil, who will decide who takes it first? What are the decision mechanisms? Will it be a political decision? What role will science play in this decision-making moment? Are we ready for mass vaccination, thinking about applying two doses in periods ranging from 14 to 60 days? And how will possible adverse effects be monitored during the pharmacovigilance phase after applications? I hope logistical planning has already begun.
Note: This text does not necessarily reflect the opinion of Unicamp.
