Clear doubts about the effectiveness of AstraZeneca: one dose of the vaccine significantly reduces hospitalizations

Recent studies conducted by the The University of Oxford has shown in the UK, where the delta variant is prevalent, that applying a single dose of AstraZeneca vaccine prevents hospitalizations in 72% of cases. Anyway, he established that the ideal is the application of two doses, even when the window between the two exceeds three months.

Argentinian pathologist Marta Cohen, residing in UK, told Infobae who spoke to him Andrew Pollard, director of vaccine research at Oxford-AstraZeneca, who personally explained the details of the study to him.

These latest analyzes have determined that “the protection of a dose of vaccine is very good, of the order of 72% with one dose of AstraZeneca to prevent hospitalization and 92% with two doses ” of this inoculant, which implies levels “Similar” to Pfizer which are “96% with two doses”.

Tests have shown that one dose would not prevent the symptoms of the infected, but the worsening of symptoms and the consequent overload of the hospital system.

Dr Pollard, Cohen added, “He explains that in his work they called the volunteers who had not received the second dose”, after which they had “The pleasant surprise that up to 45 weeks or more after the first dose, the second dose had good immunity. It’s for immunological memory ”.

“But on top of that, they called another group that got the second dose in a timely manner and they gave them the third dose and immunity. it was also very good ”, revealed.

“This would indicate that countries that have only received one dose can still administer the second dose several weeks later. And the more developed countries which received the second dose should receive a third injection ”, He said.

In short, stressed the Argentinian specialist, the study “indicates that the second dose of the Oxford-AstraZeneca vaccine awakens immunity months after the first dose ‘, although it will always imply greater protection to receive both vaccines and even, for those who accepted, a booster, a third.

In Argentina, where they have so far arrived 25,706,730 doses, 580,000 from AstraZeneca-Covishield, 1,944,000 from AstraZeneca via the WHO COVAX mechanism and 7,057,900 from AstraZeneca and Oxford whose active ingredient was produced in Argentina, according to official data.

The remainder, 10,124,830 correspond to Sputnik V (8,234,670 for component 1 and 1,890,160 for component 2) and 6 million to the Sinopharm laboratory.

What the PHE and Oxford said

On the other hand, Cohen cited an article in Public Home England (PHE) of June 14, referring to a study carried out in 14,000 symptomatic people with the delta variant between who “Only 166 had to be hospitalized.” There it was established that “The protection of the vaccine is very good, it is of the order of 72% with one dose of AstraZeneca” to avoid hospitalizations and 92% with two doses.

“It’s fantastic, it means that one dose of vaccine doesn’t necessarily prevent symptomatic infection, but one dose of vaccine prevents hospitalization or reduces the risk of requiring hospitalization,” the doctor said.

This same article specified by means of a table that “of the 166 people hospitalized with the delta variant who presented symptoms requiring hospitalization, only 6% had both doses, 52% had one dose and 42% had none, they were not vaccinated ”.

“This indicates that, then, the two doses are ideal, but in places where the second dose cannot yet be received, at least there is a good chance of a good level of prevention of hospitalization”, Cohen concluded.

As mentioned by the pathologist, the study conducted by EPS published on May 22 “shows for the first time that 2 doses of COVID-19 vaccine” from AstraZeneca “They are very effective against the B.1.617.2 variant first identified in India.”

This research showed that AstraZeneca and Pfizer “were 33% effective against symptomatic disease of B.1.617.2, 3 (delta) weeks after the first dose relative to about 50% efficacy against variant B.1.1.7 (Kent) ”.

June 28 Amy Flaxman and Natalie Marchevsky from Oxford University also published a survey in The Lancet in which they pointed out that “A longer time to the second dose” of AstraZeneca “results in an increase in antibody titer after the second dose. A third dose of ChAdOx1 nCoV-19 induces antibodies to a level correlated with high efficacy after the second dose and increases cellular responses. “

This analysis, said the authors, was carried out in the face of “the shortage of supply of COVID-19 vaccine” which “raises concerns about compromised immunity in some countries as the interval between the first and second dose lengthens ”.

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