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The current scenario in Brazil, which combines the onset of vaccination with the uncontrolled transmission of COVID-19, could turn the country into a “factory” of variants potentially capable of bypassing the efficacy of vaccines altogether.
This is the assessment of a group of British scientists directly involved in some of the main research on coronavirus mutations.
Researchers at Imperial College London and the University of Leicester argue that lockdowns and the like containment measures are particularly necessary during the vaccination of the population.
They explain that it is precisely the contact between the vaccinated and the variants that favors the appearance of “super powerful” mutations, capable of completely bypassing the action of vaccination
And, in Brazil, there is an explosive combination to make this happen: the vaccination continues at a slow pace, there is the variant with the E484k mutation (which avoids antibodies) and the infection rates are high.
The Manaus variant and vaccines
The greatest danger lies in the Manaus variant, nicknamed P.1, coming into contact with recently vaccinated people, says virologist Julian Tang of the University of Leicester in the UK.
By entering the human cell and encountering a still small amount of vaccine antibodies, the variant, by replicating, may promote more resistant mutations to these antibodies, he warns.
“If you get vaccinated on a Monday, you are not immediately protected. It takes a few weeks for the antibodies to the vaccine to appear and you can still get the original virus or the P.1 variant,” says Tang.
Brazil has broken the record for deaths in 24 hours: more than 1,800 victims of covid-19. Porto Alegre hospitals reach 100% occupancy in intensive care units.
“If these vaccine antibodies occur while the infection is occurring and spreading through the body, the virus can replicate itself in a way that escape antibodies in a natural selection process“.
This development is part of the evolutionary process of the virus, which tries to adapt to “adversity”.
A vaccinated but infected person can transmit this mutated virus if there are no control measures, such as quarantining and closing businesses and recreational spaces.
The risk of this happening would be less if the Manaus variant did not spread across the country and if infections were under control.
This is because the possibility that the parent virus could adhere in large amounts to the cells of a vaccinated person is low, since immunization is precisely what it is supposed to prevent.
But the E484k mutation, present in the Manaus variant, affects exactly the main junction point between the virus and cells, making the “coupling” and reduction of the efficiency of the so-called neutralizing antibodies.
Preliminary research indicates reduced efficacy of the Oxford-AstraZeneca vaccine against variants loaded with the E484K mutation, and the Butatan Institute is studying its impact on the percentage of protection offered by CoronaVac.
“If there is uncontrolled transmission of the virus, that is to say in an environment without social distancing rules, without confinement or the use of masks, people likely to be infected will be mixed with those vaccinated“.
“Without barriers, the virus can be transmitted between populations, potentially generating variants that escape the vaccine,” Tang told BBC News Brazil.
Brazil vaccinates around 3% of the population and is still negotiating to acquire enough vaccines to serve all residents. In some health posts, the elderly had to queue.
“And this will happen especially if there is a major epidemic situation in a country with moderate vaccine success.”
“In this way, the perfect balance between immune and infected is achieved. And when these populations mix, there is a risk that a new variant resistant to the vaccine will emerge,” the expert told BBC News Brazil.
The epidemic is out of control in Brazil
Brazil is experiencing exactly this confluence between an early vaccination phase and a peak in COVID-19 cases.
The country topped the United States in the dismal 24-hour infection record.
Data released Thursday by the World Health Organization showed that 59,900 cases of covid-19 were recorded in Brazil in 24 hours. In the United States, it was 57,800.
The number of daily deaths also continues to rise and break records.
On March 3, they signed up 1,800 deaths in one day, the highest number since the start of the pandemic. In more than half of Brazilian states, the occupancy rate of intensive care beds exceeds 80%.
In Brazil, approximately 260,000 people have died from covid-19 to date.
Faced with the collapse of health systems in several municipalities, the governors decreed blocking or social distancing measures.
Despite the uncontrolled infections, the president Jair Bolsonaro he again spoke out against the restrictions.
“As for me, we will never have confinement. It is never a policy that has not worked anywhere in the world, ”said the president.
But the data belies Bolsonaro’s line.
In the UK, lockdown in place across the country since early January has reduced COVID-19 infections by two-thirds.
In London, the drop was 80%, according to a study from Imperial College London.
“From a scientific standpoint, closing borders and enforcing home quarantines are effective in reducing infections.”
“And reducing infections has its benefits. The risk of the emergence of variants is reduced, time is saved for the vaccination campaign to advance and for research to find suitable vaccines for the variants that currently exist, ”says Professor Peter Baker.
Manaus variant may be dominant
In addition, experts warn that if control measures are not taken, the Manaus variant could eventually replace the original virus and become widespread throughout the country.
P.1 is already circulating in at least 10 Brazilian states, in addition to being responsible for almost all current infections in the capital Amazonas.
“Without control measures, P1 will quickly become the dominant virus and generate large epidemic waves, ”analyzes Charlie Whittaker, researcher at Imperial College London.
In Brazil, there were protests against the lockdown announced at the end of February.
A study by Whittaker showed that the Manaus variant is between 1.4 and 2.2 times more transmissible than the parent virus.
Research also reveals that P.1 is able to evade the immune response from previous infections in 25% to 61% of cases.
In other words, it can cause re-infections in people who have previously had covid-19.
And re-infections are another important ingredient for dangerous mutations, says Peter Baker of Imperial College London.
“When these variants come into contact with people who have already been infected, there is pressure to keep them mutating, to find a way to re-infect people who were previously immune,” he says.
“The combination of a previous epidemic and a new major epidemic, in which already immune people are reinfected, creates an environment conducive to mutations. We believe this has happened in the Brazilian context.”
A risk for everyone
In addition to being already expanding throughout Brazil, the Manaus variant has so far been detected in 25 countries, despite the fact that several countries have canceled flights to Brazil and imposed quarantines and covid tests. 19 to all who came from the south. American country.
This reveals that an uncontrolled disease in one country puts other nations at risk.
“If Brazil is allowed to replicate the virus in an uncontrolled fashion, these variants can emerge and travel anywhere,” says virologist Julian Tang of the University of Leicester.
“If you have a virus production barn in a country, if you don’t control transmission, you’re going to have mutations produced by natural selection, if those variants are going around the world and some of them are totally or partially escaped. vaccines, because of course it is a risk. ”
Researchers interviewed by BBC News Brazil believe that mass vaccination, combined with measures to restrict social contact, such as lockdowns, the use of masks and business closures, are important in containing the high rates of disease. infection and prevent new mutations, while vaccination continues. .
“No one is safe until we are all safe. And ensuring safety means limiting the possibility of variants emerging. Control measures are helpful in achieving this, but it is perhaps even more important. to ensure a fair global immunization strategy. ”
“This means that no country should be left behind,” proclaims Charlie Whittaker of Imperial College London.
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