Several countries have experienced a sharp drop in new cases of Covid-19 after the arrival of vaccines, such as the United States, the United Kingdom and Israel, leaders in vaccinating their populations.
However, it is still too early to link the drop in infections with injections, as countries like Portugal and Japan, which applied few doses, have also observed a marked decrease in contagions.
According to experts, the drop is due more to containment measures, such as lockdowns, adoption of remote work, mask wearing and social distancing, than vaccination.
Among the 50 countries that recorded the largest reduction in daily new cases between December 5 and March 5 – after three months have passed since the first vaccination in Russia – 25 have already started their vaccination campaigns. Due to the volatility of the situation, only 13 of them continue to show a steady decline after peaking between the end of last year and the beginning of this year.
The rest reached a plateau or saw new infections resurface. Among the 12 that do not show a steady decline, there are countries with advanced vaccination, such as Serbia, which has already applied at least one dose to 15% of its population. The moving average of business rose sharply after the easing of restrictive measures, which led to a further tightening, without leading to a decline in the workforce.
Others, with a lower vaccination rate, between 5% and 8%, have also relaxed restrictions. The case of Switzerland, which reached a plateau at the beginning of the month, and of Germany, where cases have again increased. India, flagged as a point off the curve to show an unrestricted decline in movement, again increased cases.
Some of the countries with a drop in contamination have been hit hard by the coronavirus. The United States, which has become the epicenter of the pandemic, saw a peak in cases in the middle of the holiday season on January 2, with a daily moving average of 905.7 cases per million population.
On March 5, the number fell 77.5% to 203.6 – when the country had 16.6% of its population vaccinated.
“It’s a mixture of many factors. Vaccines probably have some effect, but not all, ”says John Brownstein, professor of medicine at Harvard University and head of innovation at Boston Children’s Hospital in the United States. “After the holidays, people stopped traveling, reduced interactions. I think people in winter keep more social distance. “
The doctor also links the fall to a possible seasonality of the virus and to a certain natural immunity of the population. He warns, however, that this does not mean that there cannot be further outbreaks, as changes in guidelines, reopenings and the presence of new variants have already led to new highs and plateaus in the country.
“If we hold it a little longer, the vaccines will have their impact and we won’t see the big effect of the variants, but it is very possible to see outbreaks due to the new strains and the fact that the populations that are contaminated with them are young adults who have not yet been vaccinated. “
Head of the Department of Epidemiology at the University of Michigan, Joseph Eisenberg also stresses the importance of maintaining measures until herd immunity, estimated between 50% and 60%, is reached.
Israel is the country closest to that range: until last Friday (5), 56.6% had received at least one dose of the vaccine and 42.3% had already been fully vaccinated. While not among the biggest drops seen in the three months analyzed, the country saw its maximum moving average on January 17 drop from 996.4 new daily cases to 423.9 – a drop from 57.4 %.
Regarding the US scenario, Eisenberg says that, at the moment, there should not necessarily be a drop in transmission, but deaths, since the vaccines are being applied in groups at high risk for Covid-19. “It’s only when we have herd immunity that we will see a significant drop in transmission. This huge decrease in cases is probably related to other factors, ”he said, referring to the containment measures.
This helps explain why countries like South Africa, Portugal and Japan experienced some of the largest declines examined during the period. The African country saw a drop of 93.8% in the moving average of new daily cases, from 321.1 infections per million population on January 11 to 19.8 on March 5, with 0.12% of the vaccinated population.
President Cyril Ramaphosa ordered a curfew between 9 p.m. and 6 a.m. and banned the sale of alcoholic beverages on December 28. With the drop in cases, however, there has already been a relaxation of measures, with the curfew suspended – which had already been reduced – and the release of the sale of alcohol.
“Nothing that is projected is guaranteed, it will depend on whether the current trend of decreasing new cases continues,” Portuguese epidemiologist Baltazar Nunes, of the Dr Ricardo Jorge Institute, said earlier this month. , about the achievements of the European country. .
Portugal experienced its largest outbreak on January 28, when the moving average of daily cases reached 1,264.2 per million population. Days earlier, on January 22, as the country saw its numbers skyrocket, a lockdown was declared, with schools and universities closed and increased control over commercial establishments, in addition to a cover-up. stricter fire.
Thus, the moving average of daily cases was 78.9 per million inhabitants on March 5, a drop of 93.8%, while at that date the country had vaccinated 6.8% of the population.
In Japan, on the other hand, the decline was slightly smaller, but still significant. On January 11, Japan’s moving average hit 51 cases per million population, the highest figure for any pandemic in the country, a figure that fell to 8.3 on March 5 – a drop from 83.7 % over the period.
As of that date, however, only 0.04% of Japanese had been vaccinated, the lowest rate among the 13 countries analyzed. With its peak earlier this year, the government declared a state of emergency in Tokyo and three other cities in the region on January 7, extending the resolve to seven more municipalities a few days later. The measure allows local governments to restrict the movement and operation of businesses.
These rules are more or less found in the 13 countries that break records among those that have already started vaccination. The champion, Belize, a small country of 397.6 thousand inhabitants in southern Mexico, adopted a curfew between 10 p.m. and 5 a.m. on November 28, a measure which has been prolonged since and which is supplemented by restrictions to the occupation of places such as gymnasiums and churches.
The Central American nation peaked on December 9, with a moving average of 957.5 cases per million population, falling to 15.1 on March 5, down 98.4%. Vaccination, on the other hand, started recently, in the last days of February, and on March 5 was equivalent to 0.25% of the population.
Second on the list, Iceland fell from a moving average of 253.3 daily cases per million population on October 11 to 4.2 on March 5, a drop of 98.3%. The island nation, which has already vaccinated 7.92% of its population, adopted a series of measures when it reached its peak, controlling how many people can gather and how schools operate. Even with the improving figures, he now only allows entry into the country after a negative test for Covid-19 and a five-day quarantine in hotels.
Analysis of the 13 countries also indicates that a national response may be more effective than delegating restrictions to states, provinces and regions. In the list, Japan (8th place), Colombia (9th), the United States (10th), Canada (12th) and Russia (13th) adopted regionalised responses.
Colombia, for example, which recorded an 80.2% drop in the moving average of cases between its peak on January 10 (350.9 cases per million inhabitants) and March 5 (69.6). , adopted measures that only affected the main cities of the country at the end of the year.
At the start of the year, it determined mobility restrictions and banned meetings in public spaces in municipalities and departments with more than 70% of ICUs. As of March 5, 0.47% of Colombians had received at least one dose of the coronavirus vaccine.
In Russia, the country which posted the smallest decline among the group analyzed, the peak in the moving average of new daily cases, from 195.3 on December 26, fell to 75.5 on March 5, a decrease of 61.3%. Amid the increase in cases, even in November, the country’s leader, Vladimir Putin, delegated the determination of restrictions to local governments.
In Moscow, one of the epicenters of the republic in the country, limitations were imposed on the operation of educational institutions, museums, exhibitions, libraries and cultural centers, in addition to the will of a party of company employees to work remotely. However, in mid-January, these measures began to be relaxed. Although Russia was the first country to start vaccinating, with the controversial Sputnik V, only 3.36% of the population received at least one dose.