Wednesday, July 6

Why Chile is unable to control the virus despite vaccination: population boredom, failure to comply with measures and a less effective Chinese vaccine

There is a certain air of discouragement in Chile, a kind of dejection caused by the feeling that, despite the progress in the vaccination campaign, the country does not find the formula to control the third wave of the pandemic.

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Although virtually the entire country remains confined and some areas are undergoing weekend quarantines, infections are still very high and deaths exceed 100 per day, as occurred in the first stage of the health emergency.

According to the latest data from the Ministry of Health, during the last week the new daily infections have oscillated between 5,000 and almost 7,000, and the cumulative incidence of the last 14 days has revolved around 457 and 497 confirmed cases per 100,000 inhabitants. . Hospital capacity continues at critical levels, with ICU occupancy reaching 96.3% as of June 15.

Two weeks ago, the Chilean government completely confined the entire Metropolitan Region. It was the third time that this measure had been taken since the outbreak of the health crisis. Now, considering that since the beginning of the second Chilean wave some communes (neighborhoods) have been closed for more than 90 days, the authorities decided to relax some restrictions despite the fact that their incidence rates are higher than when they entered quarantine.

The other side of the pandemic, which has to do with the progress of the inoculation campaign, is much more encouraging. Up to now, more than 50% of the population is fully vaccinated (in Spain, that percentage is 32%). The injections have been administered to all age groups from 18 years old and this Tuesday they also began to immunize minors.

Sinovac, ineffective to stop infections

At the end of May, the doctor of the University of Chile Juan Carlos Said published a column in the research medium Ciper entitled Sinovac is not enough. It was one of the first voices that publicly and openly expressed why, despite the advances in vaccination, the cases of COVID-19 in Chile are not decreasing. The doctor argued that the Chinese Sinovac-CoronaVac vaccine is “ineffective” in cutting off the circulation of the virus, but not in “reducing the number of hospitalized.”

“If we compare the vaccination rates of Chile with those of other successful countries such as Israel, some states of the United States or even France, the results have been different and, in this, the effectiveness to cut the infections can be one of the factors” , explains the national secretary of the Medical College of Chile, José Miguel Bernucci. “Sinovac is a good vaccine to reduce the risk of death, the severity of the disease and the need for intensive care, but it is not as effective in cutting transmission”, agrees the vice president of the Chilean Society of Infectology (Sochinf), Claudia Cortés.

The increase in the number of cases also has to do with other factors: “There is relaxation, pandemic fatigue and a decrease in self-care; the crowds are still present, there is no control of sanitary measures and, while there are new variants circulating, the borders are not completely closed “, adds the doctor.

Genomic sequencing studies by the Institute of Public Health (ISP) have shown that, since the summer until now, the gamma variant, detected for the first time in Brazil, is the one that predominates in the country. It is a doubly contagious variant with respect to the original virus and, according to Bernucci, “it has been transmitted with greater speed and severity in young people who are, precisely, the mass that is not vaccinated.” Although there is a large pool of vaccinated population, “there are still 10 million people without complete immunity and that is a lot if we consider that the other 10 million [ya vacunados] they can also transmit the virus, “says the doctor.

Although the initial calculations of the Government of Sebastián Piñera aimed to achieve group immunity with 80% of the target population vaccinated, experts are now looking towards another horizon: “We will have to wait to be closer to 100% of the total population (minors included) to reach immunity “, predicts Bernucci.

Another change that the authorities have also begun to consider in recent days is the possibility of administering a third dose to those who have been inoculated with the Chinese vaccine. “The first people who were vaccinated with Sinovac in February received the second dose in March, according to the results that we will see in July, we could require a third dose in September,” says the Undersecretary of Health, Paula Daza.

Income of people over 70 years old increases

In the last month, the percentage that the elderly represent of the total ICU admissions went from 10% to 15%. This is another of the effects of the worsening of the pandemic that worries health personnel.

“One possibility is that older adults sometimes get the virus from younger people who participate in parties and infect their father, mother or grandfather,” said Health Minister Enrique Paris.

A preliminary study prepared by a group of researchers from different universities in Brazil, Spain and the United States, who measured the effectiveness of CoronaVac (Sinovac) against this variant in older adults, and concluded that the general efficacy of the Chinese vaccine is 42% in those older than 70 years. By sections, between 70 and 74 is when the greatest protection is reached, with 62%; Between 75 and 79, 49% are registered, and 28% with those over 80 years of age.

“Although the elderly were the first to be vaccinated, between 10% and 15% of people (and in some ages even 20%) have not been vaccinated,” recalls Bernucci. According to figures released by the president, so far in Chile there have been about two million laggards, that is, they could have been vaccinated, but did not.

Claudia Cortés recalls that the immune system ages with age and the response to vaccines in older people is weaker. Bernucci also points out that the cause-effect relationship is complex to establish because “one may think that if the person had not received the vaccine, they would have already died because the severity scale of the disease is always low”.

Buying vaccines for next year

This week the Ministry of Health intends to modify the “Step by Step” plan, which has guided the relaxation of measures (or their tightening) since the beginning of the de-escalation, at the beginning of the southern spring. A decision that the authorities have taken pushed by the Medical College, which a few days ago presented a proposal to face a crisis that the country cannot control.

Some of his suggestions will be included in the government’s new strategy, such as the opening of schools despite the fact that they are in confined communes. According to Unesco data, Chile is among the 20 countries in the world that have kept schools closed the longest (14 weeks are with total closure and 39 with partial). In South America, it is only surpassed by Bolivia and Argentina and is even with Brazil.

On the other hand, the Executive has already begun to negotiate the purchase of millions of new doses for next year. Dr. Said recommended in his column “to incorporate more effective vaccines: Pfizer, Moderna or Sputnik” for the next inoculation campaigns. An advice shared by the experts and that the president and his advisers will have to listen to in the face of this negotiation.