why do highly vaccinated countries see the number of patients increasing

why do highly vaccinated countries see the number of patients increasing
why do highly vaccinated countries see the number of patients increasing
Coronavirus: why highly vaccinated countries see the number of patients increasing

United States, Chile, United Arab Emirates … These countries are ahead of vaccination but continue to record worrying figures on the progression of the Covid.

Despite everything, it does not go down. Good pupils of the coronavirus vaccination, the United States, Chile and to a lesser extent the United Arab Emirates have a problem. No matter how hard they vaccinate since the first months of 2021, they are now facing an increase in the number of cases, unlike other top of the class like Israel.

Compared to France, which with 19 doses of vaccine per 100 inhabitants is in the middle of the world table, they have nevertheless taken a considerable lead. The United States have already administered 50 doses per hundred inhabitants, Chile 59, and the Emirates 89: figures which make you dream here in France, and which however do not prevent the bad news.

In the United States, as the number of cases, at its highest in early January, continued to collapse, it has started to rise again slightly since the end of March. In Chile, the situation is much more dramatic, since the country has just recorded a new record of infections at the beginning of the month, with a third wave which is strikingly reminiscent of the hexagonal situation. In the Emirates, the number of people affected is not decreasing, despite a particularly aggressive vaccination campaign. Should we see in these cases a bad omen? Let’s start with the good news.

In the United States, more young people are declaring themselves sick

Covid is getting younger, and that’s a good thing. It may sound contradictory, but in the United States in particular, the increase in numbers is largely due to younger people: adolescents, unlike 2020, are now the age group where the virus is increasing, while almost ‘one in two adults is vaccinated, effectively forming a barrier to infection. This phenomenon, added to the ubiquity of a more contagious British variant, changes the demographics of the virus.

For American epidemiologists, this is rather reassuring. As explained to the American channel NBC News the doctor Frederick Davis, the reported cases are overwhelmingly not serious, with hospitalizations sometimes, but more rarely than before. It is the consequence of this displacement of the infections, due to the fact that the vaccination works.

The US CDC confirms it: today in the US emergency services, there are more 25-49 years than 65 and over. Despite everything with more than 55,000 cases per day, the rejuvenation is far from sufficient to explain this rise. Of course, the sick are changing, but why are there also more of them? This is where the bad news begins.

The great relaxation

In the United States, as in Chile and the United Arab Emirates, the central problem is in fact the negative counterpart of vigorous vaccination campaigns: the population relaxes its efforts to respect barrier gestures and social distancing, sometimes with the support of public authorities which stopped too soon the restrictions on movements, gatherings and the opening of businesses.

The case of Chile is particularly telling in this respect. The country records nearly 7,000 contaminations per day despite an impeccable record of the number of vaccinations: 7.1 million people have received at least one dose of vaccine in this country of 19 million inhabitants. But as the president of the Chilean Doctors Association explained to the New York Times, these good figures have given Chileans, exhausted by the pandemic, “a deceptive feeling of security”.

The Chilean government is also said to have contributed to this upturn, by dropping restrictions on business activity as soon as possible. To allow Chileans to go on vacation, an interregional travel permit was also created in January, when vaccination was still in its infancy.

The result: what many see as a “race against time” between vaccination and the relaxation of barrier measures turns to the benefit of the disease. A study from the University of York, Ontario, in January 2021 sought to quantify the conditions under which vaccination could “speed up” the number of contaminations, and thus avoid a Chilean scenario.

The conclusions are very clear: without control measures taken throughout the vaccination campaign, the number of contaminations is not likely to decrease, but on the contrary to increase. It is also a problem for the United Arab Emirates, which is very dependent on their commercial activities, which is experiencing a recovery similar to that experienced by the United States after a partial reopening of their businesses, especially in Dubai.

Vaccine efficacy in question

The other variable, in addition to the restrictions to reduce contact, is of course vaccine efficacy. The authors of the study estimate that with a vaccine effective at 70%, a significant increase in the number of contacts in the population is not likely to make excessively take off the number of cases. Below, the problem is quite different. And here again, Chile is more of a counter-example.

The country, largely funded by the Covax international aid fund, has relied heavily on the vaccine from the Chinese laboratory Sinovac to implement its vaccination blitz. With its millions of vaccinated inhabitants, the country has just produced a large-scale study on the effectiveness of the latter against Covid, and the figures are not good, without being catastrophic.

The Sinovac vaccine, says the University of Chile, is 54.4% effective against the coronavirus two weeks after receiving the second dose, and 27.7% after just one dose. It is certainly beyond the threshold of 50% necessary for the vaccine to be considered sufficiently effective by the health authorities, but it is considerably below Pfizer, Moderna, or Astrazeneca. But there is worse.

With just over 50% effectiveness, the Sinovac vaccine in Chile could have contributed to the poor contamination figures, in a scenario precisely described by the Canadian study: “a mass vaccination with vaccines of low efficacy will always increase the rate of reproduction of the disease, even if the efforts to quarantine the unvaccinated are high ”. Concretely, the vaccinated people relax their precautions, while their immunity is not total. And the virus, which circulated a lot in the country at the beginning of the vaccination campaign, continues its devastation, without a collective immunity coming to stop it.

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