Even vaccines that do well on tests will go a long way before being applied to people, including a gigantic structure to manufacture, fill and distribute millions of doses worldwide.
Amid widespread anxiety over the approval of a safe and effective vaccine against covid-19, experts hold the expectation that a solution to contain the pandemic will be available to the entire population from December 2020 or early 2021.
The message came on Wednesday (14/10) by the chief scientist of WHO (World Health Organization), Soumya Swaminathan. “For an ordinary, young and healthy person, it may be necessary to wait until 2022 to get the vaccine.”
According to the analysis, it is likely that the world will have an immunizer by 2021, but it should be restricted at first to health professionals, the elderly and people with chronic diseases, such as diabetes and hypertension.
In an interview with the CNN Brasil broadcaster on Tuesday, the sanitarian Mariângela Simão, deputy director-general of WHO, also stated that it is impossible to think about a mass immunization against Sars-CoV-2 in Brazil in 2021.
“There will not be enough vaccine next year for the entire population, so what the WHO is advising is that there is a prioritization for health professionals and people over 65 or who have an associated disease,” said the expert.
Currently, 213 candidates for the covid-19 vaccine are in development. Of these, 36 are in the clinical research stage, which involves testing with humans? in this group, there are nine immunizing agents in phase 3 of the studies, the last step before final approval by country regulatory agencies.
Although this race has many competitors, the challenges are not limited to scientific experiments: even those vaccines that do well in tests will go a long way before being applied to people. After all, it is necessary to create a gigantic structure to manufacture, fill and distribute millions and millions of doses to the entire planet.
Considering that humanity will not be able to produce billions of coronavirus vaccines overnight, scientists and public health officials are working to answer a rather complicated question: who should be the first groups to be immunized?
The H1N1 pandemic that occurred between 2009 and 2010 may offer some clues as to how humanity will deal with this issue.
Another virus, another story
According to data from the United States Center for Disease Control and Prevention (CDC), the H1N1 influenza virus responsible for the 2009 pandemic caused between 151,000 and 575,000 deaths in the first twelve months.
Did the disease appear in mid-April in Mexico and soon spread to several countries? WHO established a pandemic peak on June 11 of that year.
The difference between past and present is precisely how fast (or how long) it takes to develop a vaccine: on June 12, 2009, the day after the WHO pandemic decree, Swiss pharmacist Novartis announced that it had developed a first version of the immunizer against the new strain of H1N1.
Three months and three days after that first good news, the Food and Drug Administration (FDA), the American regulatory agency, approved four types of vaccines against this pandemic influenza. And in October 2009, a massive immunization campaign was already underway in the United States.
But how was it possible to do the whole process at this speed? “We speak of a disease with which we already had extensive experience in prevention and treatment and there was a whole structure set up for the manufacture of vaccines”, says pediatric infectious disease Renato Kfouri, director of the Brazilian Society of Immunizations (SBIm).
Therefore, as flu vaccination was already routine in many countries, experts were able to use this expertise to contain the pandemic relatively quickly.
In Brazil, immunization against pandemic H1N1 started in March 2010 and its main objective was to contain a “second wave” of cases in early autumn and winter from April to May of that year.
In a technical note, the Ministry of Health defined five priority groups for vaccination: indigenous people in villages; pregnant women; people with chronic diseases; children older than six months to two years of age; young adults between 20 and 39 years old.
Contrary to what normally happens in regular flu campaigns, the elderly did not form part of the priority vaccination groups for that specific influenza.
“Older people are believed to have had some contact with a variant of this H1N1 in past decades, which gave them greater protection in that 2009,” explains Kfouri.
The data indicate that this strain of influenza affected young people more frequently: data from the period estimate that adults aged 20 to 29 years accounted for 24% of cases of Severe Acute Respiratory Syndrome (SARS), one of the most serious manifestations of influenza. Have individuals between 30 and 39 years old been the age group with the highest mortality from the disease at that time? hence the need to protect this age group as soon as possible.
Back to the present
While vaccines against covid-19 are not approved, public health officials are already discussing how to define who will be the priority groups for the campaigns. For now, there are many proposals and ideas, but few definitions.
A report published in the newspaper O Globo on August 10 points out that the Health Surveillance Secretary of the Ministry of Health, Arnaldo Medeiros, had proposed that the government use the same strategy as the flu immunization campaigns in the current pandemic.
The idea has aroused a lot of criticism, since the groups at risk for influenza and covid-19 have many differences. Children, for example, are part of the target audience for immunization against influenza. However, the evidence indicates that they are little affected by the coronavirus that is currently in circulation.
In the state of São Paulo, health secretary Jean Gorinchteyn announced at a news conference on October 5 that the first phase of vaccination in the state will include health professionals. Then, educators and people with chronic diseases would be contemplated.
There is even a bill in the Chamber of Deputies in Brasília that seeks to establish an order for access to the vaccine against covid-19.
Authored by Wolney Queiroz (PDT-PE), the document argues that the first recipients are professionals essential to disease control and the maintenance of public order, followed by people over 60, individuals with chronic diseases, teachers and professionals support in public and private schools, public servants, journalists and, finally, the healthy population under 60.
As much as there are many ideas under discussion, the Ministry of Health will beat the hammer. “The scenario will be designed not by governors or deputies, but by members of technical chambers, with experience in the national immunization program”, adds Kfouri.
The proposals on priority groups appear to be a little more advanced in international bodies and some countries in the Northern Hemisphere.
In a statement published on September 14, the WHO Strategic Advisory Group on Immunization Specialists (Sage) says that immunizers are a public good. “The general objective is that vaccines against covid-19 contribute significantly to equitable protection and promotion of human well-being among all peoples,” write the experts.
Along these lines, there are initiatives for vaccines to be offered first to priority groups worldwide before they are made available to the general population of countries with better conditions to manufacture or buy doses.
In practice, health professionals and the elderly from all nations would be immunized before others. “This would require a major global discussion, with multilateral agreements, partnerships and patent breaks,” predicts Kfouri.
In the United Kingdom, the Joint Vaccination and Immunization Committee, which brings together experts from several universities, issued an opinion on September 25 that defines the following order of priority:
– Elderly people who need care at home and their caregivers;
– All over 80 years old and health and social service professionals;
– Everyone aged 75 or over;
– Everyone aged 70 or over;
– All aged 65 and over;
– High-risk adults under 65;
– Moderate risk adults under the age of 65;
– Everyone aged 60 or under;
– Everyone aged 55 or under;
– Everyone aged 50 or under;
– The rest of the population.
In the document, the experts themselves admit that this strategy can be completely modified according to the results of phase 3 studies of the vaccine candidates, which should be released in the coming months.
If the first approved immunizers prove to be ineffective in the elderly and work well in young adults, the regimens will be changed.
In the United States, the National Academies of Science, Engineering and Medicine have also drawn up a vaccination plan against the coronavirus. The proposal has important changes when compared to the UK version:
– Phase 1a: high-risk workers in health units and emergency services;
– Phase 1b: people of all ages with chronic diseases at high risk of complications and elderly people living with other people or in places with a high population concentration;
– Phase 2: workers in industries and services essential to the economy with a high risk of exposure to the virus; school teachers and staff; people of all ages with chronic diseases with a moderate risk of complications; elderly people not included in phase 1; individuals living in hostels or on the streets; patients with physical or mental disabilities; people in prisons and detention centers; prison staff;
– Phase 3: young adults; children; workers in industries and services essential to the economy with a high risk of exposure to the virus who were not included in phase 1 or 2;
– Phase 4: all residents in the United States who have not received doses in the previous phases.
Can you copy?
As much as foreign models serve as inspiration, Renato Kfouri does not believe that it is possible to adopt a single path for all countries.
“It is necessary to take into account the particularities of each location, such as the age pyramid, the number of elderly people and the size of the population”, points out the director of SBIm.
Predictions about whether mass vaccination will occur in 2021 or 2022 also depend on the type of vaccine that will be approved by regulatory agencies. “Some synthetic immunizers can be produced on a large scale in a short period of time, while others, which require living organisms and more complex laboratories, can take time,” says Kfouri.
Nor, in the current scenario, is it possible to rely on a policy adopted to contain the H1N1 pandemic, about 11 years ago. “At that time, we did not learn to use masks. Countries did not cooperate very much in relation to vaccines. We could have learned more from this experience in 2009 and developed better strategies to deal with the Covid-19 pandemic now”, laments the doctor.