COVID-19 vaccine campaigns in Latin Americalag well behind those in the global north. But Chile has been an outlier. It has defied the regional trend and plowed ahead with a campaign that has fully vaccinated a higher percentage of its population than any other country with more than 10 million inhabitants. By the end of March more than one in three Chileans had received a full course of vaccination for COVID-19.
But while it has celebrated its successes, Chile has also served as a cautionary tale about the dangers of vaccine complacency. Coronavirus infections have surged there in recent months, reaching a record high of 9,151 daily cases on April 9. Most intensive care units have been operating near capacity for the past month as around 100 COVID-19 deaths have been recorded each day.
Chile swiftly rolled back public health restrictions in 2021, after securing large vaccine deals with global pharmaceutical companies—primarily Sinovac but also other firms, including the Pfizer-BioNTech collaboration. It began vaccinating frontline health workers on December 24, 2020. In March schools reopened, and high-risk activities such as indoor sports, gyms and casinos were allowed to resume.
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The reopening was premature, public health experts say. Now, unlike Israel and the U.K., which are smoothly peeling back restrictions as more vaccines are rolled out, Chile has had to make a U-turn and clamp down on personal freedoms once again. Later in March authorities reimposed strict lockdowns on most of the country and even paused permits that allowed Chileans to buy groceries in what they called a “last effort” to bring infections down.
“We started relaxing lockdowns and social distancing measures before we had a significant percentage of the population effectively immunized against COVID-19,” says Juan Carlos Said, an internal medicine specialist at the Sótero del Río Care Complex in Santiago, Chile. “Now we are in a situation where, even though we have vaccinated a lot of people, we still do not have the pandemic under control.”
A study published in Science on April 27 found that COVID-19 infections and fatalities were higher in poor communities in Santiago. Lower socioeconomic status (SES) areas had not adhered as much to stay-at-home orders, “possibly because people from lower SES areas are unable to work from home, leaving them at a higher disease risk,” according to the paper. The worst-hit areas also had inferior testing and tracing. The government, Said says, should have recognized where to focus public health measures to drive down infections before relaxing restrictions. Instead it issued permits that allowed millions of people to travel around the country.
“It’s the same as treating a patient in a hospital,” Said says. “You cannot say, ‘I’m just going to perform a good surgery, but I’m not going to take care of rehabilitation or antibiotics.’ You need to do a lot of steps very well, and I think that we placed a lot of confidence in one thing.”
Public health in Chile was also undermined by politicians who were eager to ensure that they would score points for the nation’s vaccination campaign instead of emphasizing the need for a multipronged strategy that would embrace safety measures, says Claudia Cortés, an infectious diseases specialist at the University of Chile. “It was like a party every time a new batch of vaccinations arrived, with the president and health minister celebrating them at the airport,” she says. “It gives a message, not just in words but in the feeling of extreme happiness and success, that ‘we have the first batch of vaccines, and we are done.’”
In the first months of the year, millions of Chileans, fatigued with the pandemic after almost a year of restrictions, vacationed around the country. They abandoned the use of masks and gathered in crowds. Chile’s health minister admitted in March that the careless behavior of holidaymakers caused the spike in infections and that authorities should have been clearer that vaccines alone are not a panacea.
Cortés hopes other nations will be more cautious in their tone and coherent in conveying the message that vaccines are not an instant solution. “You need to keep telling the entire population that they need to take care of themselves, wash their hands, use a mask and avoid crowds,” she says. “The message needs to be very, very clear and very explicit.”
The spike in cases also highlights the need to ensure that members of the public are aware that they will not be fully protected until they get all of their prescribed vaccine doses, says Eduardo Undurraga, a global health expert at the Pontifical Catholic University of Chile.
A study presented by researchers at the University of Chile on April 6 found that the CoronaVac vaccine, made by the Chinese manufacturer Sinovac Biotech, was 56.5 percent effective in preventing infections two weeks after a second dose. But it only reached 3 percent after the first shot.
Of the vaccines administered, 85 percent were CoronaVac, and most Chileans did not understand that they would not have a strong immune response until two weeks after the second dose, Undurraga says. By early 2020 the majority of Chileans had only received one dose rather than two, and they may have been transmitting the coronavirus unknowingly or even getting sick themselves.
“We need to transmit a consistent message to avoid this idea of a silver bullet, because we know there’s no silver bullet for this pandemic,” Undurraga says.
New variants of the coronavirus that are better at spreading and evading antibodies—such as P.1, which originated in Brazil—are also believed to have driven up infection rates in Chile. As the spread of new variants pushes the herd immunity threshold higher across the world, the public must remain patient, and governments need to stay firm, with restrictions for a while longer, Said says.
“[The Chilean government] did a good job in buying vaccines, but they lacked the confidence to keep doing the public health measures that were needed to stop the circulation of the virus,” Said says. “The key message here is that you cannot focus your strategy only on one thing. There’s only one way to do things properly but many different ways to fail.”
Read more about the coronavirus outbreak from Scientific Americanhere. And read coverage from our international network of magazines here.