Chile and Uruguay, from model to emergency

Chile and Uruguay emerged as model cases last year for their handling of the COVID-19 crisis and are among the top five countries in the world with the most vaccine doses administered per 100 people daily. But both countries are now experiencing their worst moment of the pandemic with sustained peaks of daily COVID-19 infections.

The relaxation of self-care measures — hand hygiene, masks and social distancing — along with the political handling of the crisis, and the appearance of more infectious variants, may be some of the factors behind this situation, say experts.

In Chile, 30 per cent of the population has been inoculated since the COVID-19 vaccination campaign began in February. More than a third of those have received the second dose.

“It is important to slow down the rate of contagion in the middle of the vaccination campaign because the increase in cases may bring about the emergence of new variants,”

Pilar Moreno, researcher, Republic University and Institut Pasteur de Montevideo

In Uruguay, where vaccination began late February, more than 830,000 people [23 per cent of the population] have received one dose and about 200,000 [five per cent] have had two doses.

However, with record case numbers in both countries, experts agree that control measures must be maintained.

Pilar Moreno, researcher at Republic University and the Institut Pasteur de Montevideo, said: “It is important to slow down the rate of contagion in the middle of the vaccination campaign because the increase in cases may bring about the emergence of new variants.”

World Health Organization director-general Tedros Adhanom Ghebreyesus told a briefing on Monday [12 April] that there had been seven consecutive weeks of increasing cases and four weeks of increasing deaths globally, despite more than 780 million vaccine doses administered.

“Make no mistake, vaccines are a vital and powerful tool. But they are not the only tool,” he said, adding: “Physical distancing works. Masks work. Hand hygiene works. Ventilation works. Surveillance, testing, contact tracing […] all work to stop infections and save lives.”

Record daily cases

In March both Chile and Uruguay witnessed the most pronounced increases in cases since the start of the pandemic, while April brought record numbers of daily cases.

On 9 April, Chile registered a record high 9,171 daily COVID-19 cases, well above the 2020 winter peak of 6,938 cases.

In Uruguay, daily cases peaked on 7 April, with 3,935 new infections, while on 9 April a daily record of 52 deaths was recorded.

Looking to explain the situation in Chile, experts point to the relaxation of measures in the “Paso a paso” [Step by step] strategy, the Chilean government’s roadmap for managing the pandemic.

Juan Pablo Torres, infectious disease specialist at the University of Chile School of Medicine, said: “The message of relaxation was transmitted, especially with summer vacation [January to March].” The rules were eased to allow people to move within the country, which may have resulted in people also relaxing self-care measures, he explained.

“Traceability and isolation” processes are also “deficient” in Chile, Torres added. In the recent test-traceability-isolation monitoring report at primary health care level, one in three centers said they were not tracing suspected cases. In previous reports, that number was less than one in ten.

Holiday season

Katia Abarca, an academic at the Pontifical Catholic University of Chile and medical director of one of the Sinovac vaccine studies in Chile, says the opening of international borders has contributed to rising infection rates. “This allowed new variants [from Brazil and the UK] to reach Chile,” she said.

Borders have only just been closed, on 5 April. “The government has had great concern for the economy, but without health we have no economy,” said Abarca.

By the end of March, Chile’s Ministry of Health had identified 64 cases of the UK variant and 45 of the Brazilian variant [P1]. “The problem is that sequencing [to identify variants] is slow and cumbersome,” said Abarca. At the end of March, the Chilean Ministry of Science said university laboratories would join efforts to sequence the virus, increasing weekly sequences from 150 to 500.

In Uruguay an inter-institutional working group for the genomic surveillance of SARS-CoV-2 led by the Institut Pasteur de Montevideo announced on 23 March the detection of P1 in the country. Since then studies based on national samples reveal that its prevalence has increased. The UK variant has not been identified.

Although experts from both countries believe the surge in infections could be partly down to the high transmissibility of new variants, there is no data to confirm this.

Vaccine rollout

In Chile and Uruguay, but also Brazil, Argentina and Paraguay, “the case curve is very similar, with a rise in mid-January and another since the second half of February,” said Ximena Aguilera, director of the Center of Epidemiology and Health Policies of the Faculty of Medicine from Universidad del Desarrollo, and member of the COVID-19 advisory council of the Chilean Ministry of Health.

Christmas and New Year’s Eve celebrations in 2020, followed by the summer recess, could partly explain this. “It would be the reason why cases in the region did not drop considerably during the summer, as it did in the northern hemisphere,” said Aguilera.

One month later, both countries started rigorous vaccination campaigns.

“In Uruguay vaccination is good. But we are in an exponential phase of infections and we have to wait until May to see the effect of the vaccine on the population,” said Moreno.

In Uruguay, of the total vaccinated people with one dose, about 20 per cent received Pfizer and the rest the Sinovac vaccine.

In Chile, according to official figures, the occupancy of critical beds among over 70-year-olds fell 13 per cent in March. Eighty-three per cent of this group are vaccinated. In the same month, among people aged 40 to 49 years [with a vaccination rate of one per cent] infections increased by 158 per cent.

“This shows that as long as herd immunity is not achieved, self-care measures cannot be relaxed,” added Torres.

This article was produced by SciDev.Net’s Latin America and Caribbean desk.