Brazilians can take 4th wave lessons in Europe, say epidemiologists

Could the fourth wave that scares Europe this end of the year arrive in Brazil in a few months? Can Brazilians remove any connection from the European situation and prevent the country from going down the same paths?

The first lesson, according to specialists, is that, like the European continent, Brazil has great regional diversity and no conclusion or measure will be valid for everyone.

“It is necessary to monitor each region as closely as possible, to notice an increase in contagion, to understand what is causing it and to act appropriately,” the executive director of the WHO (World Health Organization) said on Thursday (25th). , Michael Ryan.

He said the ability to quickly analyze microdata is one of the weapons that is enabling the UK to avoid tougher general restrictions, such as those adopted recently in the Netherlands and Austria.

Another key action to stop further damage from the pandemic is to increase the percentage of those vaccinated as much as possible and, where the campaign is already underway, reinforce the immunization of the population approximately six months after complete vaccination, says Raghib Ali, senior clinical researcher at the Cambridge University MRC Epidemiology Unit (UK).

At that point, he says, European governments themselves could have already learned their lesson from Israel, “which suffered a strong fourth wave a few months ago, controlled by boosting vaccinations” in August of this year.

Unlike some European countries where citizens are reluctant to take Covid injections, Israel had a sizable percentage of those immunized, but even the remaining 20% ​​or 30% is enough to keep the pathogen circulating, particularly the more contagious delta variant.

In addition, evidence suggests that the protection against infection offered by the vaccine drops considerably over time, says Ali.

This reduction varies by manufacturer — in the case of Pfizer, for example, protection against contagion drops to 20% after five months, according to the researcher.

That is what explains the resurgence of cases even in countries that have surpassed 75% of the total population fully immunized, such as Belgium and Ireland, he says.

Vaccination of children from 5 years of age, authorized on Thursday (25) by the European regulatory agency, could also help contain the pandemic, says Jeremy Rossman, professor of virology at the University of Kent (UK).

Ali also raises the hypothesis that countries that suffered the most during Covid’s first wave, such as Italy and Spain, may now also be benefiting from the natural immunity developed by those who recovered from the disease — which, in theory, could also happen in the Brazil.

The effect, however, is difficult to estimate, as only the UK does this follow-up systematically. Last month’s survey indicated that 97% of the country’s inhabitants have antibodies against Sars-Cov-2, part of them because they have come into contact with the pathogen, says Ali.

Another lesson for policymakers who want to avoid a fourth wave is not to abruptly remove restrictions on movement and contact when the number of cases and deaths is declining, says WHO technical leader Maria van Kerkhove.

“The measures need to be adjusted slowly, taking into account all the epidemiological information, the percentage of vaccinees, the protection of the most vulnerable and, above all, communicating clearly with the population”, she says.

Relaxing the rules cannot mean a reduction in vigilance either, says Van Kerkhove. “The pandemic is dynamic, the coronavirus is on the lookout to take advantage of new loopholes, and if that happens, it is necessary to detect and correct the course.”

“Overall, what Brazil can learn from the current experience in Europe is that you can’t just rely on protection from vaccination and previous infection,” says Rossman. According to him, additional public health measures are still needed, and without them, the chance of another wave of infections grows — a recommendation also defended by the World Health Organization.

“In the same way that we buckle up when driving, we should routinely wash our hands, wear a mask in closed or crowded spaces, cover coughs and sneezes, and keep our distance from others to protect each other,” it said.

Reducing contagion, and not just hospitalizations, is important to avoid the risk of mutations, cases of long Covid not yet sufficiently studied, and serious illness or death in those who cannot be vaccinated — which includes children who, despite the lower risk, they can also become seriously ill.

Rossman says there is evidence that indoor use of face masks “is very effective in minimizing infection” and prevents closures and confinements, but all of these practices take time to show results.

“Starting early the combination of vaccination, tests, use of masks, restriction of crowding and communication allows avoiding the peak of infections and eliminating the need for blocks”, says the professor.

Rossman says that, although Brazil’s vaccination rate is not low and the country is already applying booster doses, there are still no guarantees that a fourth wave will be avoided without additional protective measures. Furthermore, there is a risk of a mutation that escapes the effect of the immunization.

“We simply cannot rely on just one measure. The more layers of prevention we overlay and the more we recognize that the pandemic is still going on, the better it will be,” says Rossman.

fourth wave lessons

How to avoid a new spike in cases and deaths

1 – Public health measures

• Vaccinate as many elderly, vulnerable and health professionals as possible
• Vaccinate as much of the adult population as possible
• Listening to those who refuse the vaccine to understand their reasons, answer their questions and restore confidence in immunization
• Vaccinate young people and children, in countries where there are enough and already approved immunization agents for these age groups
• Give all adults a booster dose six months after full vaccination, prioritizing elderly and vulnerable
• Maintain testing system, contact tracking and isolation of suspected cases
• Keep clear guidelines against crowding and using a mask indoors or where distancing is not possible
• Disclose information clearly and transparently
• When numbers ebb, withdraw restrictions gradually, without reducing vigilance

2 – Individual measurements

• Get fully vaccinated and take the booster six months after full vaccination, if available.
• Avoid agglomerations and closed places
• Wear masks when distancing is impossible; effective mask use involves covering your mouth and nose and avoiding contamination by removing the mask.
• Cover mouth and nose with the inside of the elbow when coughing or sneezing, to avoid hand-transmission of the virus
• Wash your hands constantly, with soap, for at least 20 seconds
• Test yourself for symptoms and avoid contact until you get a negative result
• Isolate yourself and notify contacts if you have a positive result