Chile - Why are Covid-19 cases rising?

The country's successful vaccination campaign has prevented deaths, but case numbers are still far too high.

While many countries are underperforming or simply limited by supplies, there is one Latin American country that has vastly over-performed expectations on vaccines: Chile. Around 6.8 million people have received at least one dose of the vaccine in a country with fewer than 20 million people. 

That’s what makes the rise in cases and hospitalization rates in Chile so frustrating and frightening. For Chile, March 2021 had more recorded cases of Covid-19 than any other month of the pandemic. In recent weeks, Chile has had to reimpose lockdown measures and postpone its municipal and constitutional convention elections for several weeks due to the rising cases and the full hospital systems.

In this graph of the last six months of new cases, you can see that Chile has around the same number of new cases per capita as Brazil.

Source: Our World in Data

But if you look at the numbers of deaths per capita, Chile’s have been relatively steady while Brazil’s have rocketed to the worst in the world. (Chile’s small spike at the end of the graph is due to a single recent day of data and it’s not clear yet whether it’s a trend or an anomaly.)

The fact that Chile’s mortality rate has remained relatively low in spite of the spike in cases can likely be credited to the vaccine campaign. 

But the growth in cases is still very concerning. There appear to be three reasons that cases are spiking in Chile, some of which are shared by other countries in Latin America:

Variants. New variants are spreading around South America. Those variants appear to impact younger people in a greater way than the original variant of Covid-19 (I think the current data show that they are more transmissible but it’s not clear if they are more lethal, but that analysis could change. Hospitalization rates among young people for Covid-19 show that something is going on that makes the new variants more dangerous for younger age groups). 

Reopenings. Multiple news articles cite Chile’s reopening in recent months as a reason for the rise in cases. Chile reduced its restrictions and quarantines and then many people went on vacation in February. The renewed restrictions just imposed by the government, however, aren’t without controversy. This Al Jazeera article does an excellent job describing critiques of the government’s inability to help the poor during lockdowns. 

Vaccine choices. Chile’s vaccination campaign has included millions of doses from Sinovac. Countries should operate on the assumption that the vaccine is as effective as advertised, which is about 50% effectiveness in preventing symptomatic cases and better than that in terms of reducing hospitalizations and fatalities. That’s great! It is almost certain that the Sinovac vaccine is better than no vaccine and the rapid vaccination campaign will help prevent a large number of deaths in Chile in the coming months. At the same time, while initial studies of other vaccines are showing that they are quite effective at preventing the spread of the virus (though more data are needed; keep wearing masks!), basic math suggests the Sinovac vaccine is likely less effective in terms of reducing transmission because it has a lower effectiveness rate in terms of infections than other vaccines. A significant number of people who are vaccinated with the Sinovac vaccine, even if they are better protected from worst case outcomes, can still spread the virus to others. 

I get nervous about writing that because we don’t want citizens or governments waiting for a better vaccine. If the choice is Sinovac today or a more effective vaccine six months from now, getting people vaccinated rapidly is almost certainly the better option. See the mortality rate chart above if you need further proof. However, some social distancing and mask wearing is still going to be necessary, even among the vaccinated for a greater amount of time if the primary vaccines in use have lower effectiveness rates. Governments, particularly those relying on less effective vaccines, need stronger messages about the fact that vaccination campaigns do not mean the pandemic is totally over.

Chile’s case rise is a warning for the rest of Latin America

I included Argentina and Colombia in the charts above, both of which are seeing a renewed spike in cases. In terms of vaccinations, those countries (plus nearly every other country in Latin America) are more similar to Brazil than Chile and that’s not likely to change in the coming month. The experiences in Chile and Brazil are a reason to be concerned that other countries in Latin America are going to see bad months ahead. In the race of the variants vs the vaccines, Chile is the only country even close to having the vaccination campaign win. 

Thanks for reading

Have a good afternoon.