The laudable introduction of the vaccine in Chile fails to save it from the Covid wave

Barely a month ago, the center-right Chilean government boasted about its model of introducing the Covid-19 vaccine, as it ran ahead of the rest of Latin America – and most of the world.

But since then the mood in Santiago has darkened. Chile’s impressive vaccine program has not spared it from the recent rise in coronavirus cases in the region, which have at least doubled in Chile and most neighboring countries over the past few weeks.

“Nowhere are infections more worrying than in South America, where cases are increasing in almost all countries,” Carissa Etienne, director of the Pan American Health Organization (PAHO), told a news conference on Wednesday.

Despite high vaccination rates in Chile, experts say more infectious variants of the virus, relaxation of social distancing and increased mobility have contributed to an increase in the number of cases, illustrating that vaccination alone is not a cure.

“We did not expect an impact [of vaccines on infections] by June or even July, ”said Miguel O’Ryan, a professor at the University of Chile’s School of Medicine who is a member of the Chilean ministry’s coronavirus vaccine advisory board. “What we are seeing now is simply – and tragically – what happened in the entire northern hemisphere, with a few exceptions, as autumn began. [six months ago]. ”

Local experts say the jump in infections in Chile is unlikely to be due to the effectiveness rate of the Chinese Sinovac vaccine, which received more than 90 percent of those vaccinated. Other vaccines are now arriving in larger quantities.

The Brazilian Butantan Institute announced in January that last night’s CoronaVac vaccine had an overall efficacy rate in trials of 50.4 percent, just above the 50 percent minimum threshold for the vaccine to be considered viable. However, it has been found to be 100 percent effective in preventing serious cases that require hospitalization or intensive care.

Police officers on Monday are checking citizens for permits that allow them to move through the streets of Santiago, the capital of Chile

Police officers on Monday check citizens for permits that allow them to move through the streets of Santiago, the capital of Chile © Marcelo Hernandez / Getty Images

Jarbas Barbosa, assistant director of PAHO, agrees that vaccination programs will have a delayed effect, as as many as 70-80 percent of the population needs to be immunized to prevent the virus from spreading. “We really don’t know yet what level it will provide. . . herd immunity, ”he said, adding that it is therefore crucial to keep all measures [in place] which can prevent transmission ”.

For Ximena Aguilera, an epidemiologist on the advisory council of the Chilean Ministry of Health, there are three broad reasons for the jump in daily coronavirus cases in Chile from less than 3,500 at the end of February to about 7,000 now.

The first is the spread of new, more virulent strains of the virus, especially from Brazil. Second, Chileans move more after returning from the summer holidays in March. And third, he said he was less strict about social distancing, in part because people felt safer because of the vaccination program – but also because of the fatigue of being locked up.

A graph showing that mobility levels in Chile were relatively high when the vaccination campaign was launched, while in the UK and Israel, restrictions have already reduced mobility.  This meant that the Chilean vaccination campaign intensified with already growing infections, while the UK and Israel had already knocked down infections before the introduction of the vaccine

In addition, Sinovac does not work completely after the second dose, unlike BioNTech / Pfizer, which is much more effective after just one dose. Although about 40 percent of Chileans have received one dose so far, less than half of those have had two. A recent study on the effectiveness of a vaccination program in Chile found that two weeks after receiving a second sting, it was 56 percent effective, but with a single sting, the effectiveness drops to just 3 percent.

“The government was too optimistic in believing that its successful vaccination program would avoid a new wave of contagion,” said Eduardo Engel, an economist who co-authored the report, explaining that in early February the government had the impression that a single dose was likely to have a significant effect.

“This has led to people relaxing too much, while the government has not been very strict in enforcing restrictions. The second factor is that the government has done little to stop new variants of entering the country, even though it has known since December that it is a major risk factor, “he added.

O’Ryan pointed out that while the steep curve of cases in Chile may seem alarming, the death toll is not rising as sharply as in the first wave, which peaked in June last year. That’s because the most vulnerable are vaccinated, with fewer older people in intensive care units – these are mostly adults in their 40s and 50s, who were less likely to die than Covid, he said.

A graph showing that Chile’s renaissance has been less steep than in other Latin American countries, suggesting that the vaccine may be slowing growth rates

But only when vaccinations reach the most mobile population group most likely to spread the virus – people between the ages of 20 and 55 – will cases begin to decline significantly, he added.

Mercedes López Nitsche, director of the immunology department at the University of Chile, stressed that there was no “magic wand” when handling pandemics. “To think that the whole solution can rely on just one strategy is a conceptual mistake,” she said, arguing that the vaccination program, however, is not successful.

Etienne of PAHO said similarly. “Vaccines are just one part of our response to Covid – and we must continue to rely on public health measures to keep our people and our countries safe,” she said.

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