how long does the protection last for the second dose and why the third will not be given until 2022

Among the variety of infectologists who have some type of contact with the government of Alberto Fernández – whether they are advisers or occupy positions in the Ministry of Health of the Nation – there is a sort of “round table” of the president. . They have the most important word on the subject of thvaccination strategies.

They say something about vaccines and this is discussed at every meeting of the Federal Health Council (CoFeSa). This is the National Vaccination Commission (CoNaIn).

If the national health authorities do not define themselves, doubt and even contradict each other, in the CoNaIn – although this is only explicit within this circle – experts agree that the “third dose plan” has already been activated in Argentina.

The United States has already announced that will administer it from September 20 in people who received the second dose eight months previously, Chile and Uruguay are already doing so. In fact, Uruguayans are even talking about a fourth dose. Argentina, on the other hand, has barely announced that “there is the possibility”, although it does not plan to do so before the end of the year.

We can say that the silence of the CoNaIn on this question is due to the fact that there is no place for the third doses on a territory which, at the federal level, shows the serious lack of the second.

This is explained by Eduardo López, the renowned infectologist at the Ricardo Gutiérrez children’s hospital and adviser to the executive since the start of the pandemic.

“The United States has already cleared the third dose of the vaccine for people who are immunocompromised. The government in the room is talking about it, but it’s limbo. It is a ball that is kicked for later. The key today is to have as many people as protected with both doses against Delta. If we had the vaccines, today I would give third doses to people who are immunocompromised and over 60 years old, ”López told Bugle.

France and Germany, before the United States, have already decided to recommend that immunocompromised receive a third dose.

Buenos Aires Health Minister Nicolás Kreplak contradicted Carla Vizzotti, his peer in the Nation, when he said he did not believe “that the third dose is a reality that must be achieved”. vaccine conspiracy theories: “It would seem a laboratory campaign; be careful”.

All of this, he said last week, two hours after Vizzotti announced that the third dose is not only “a possibility that has always been present” but even gave a date: “It won’t happen until next year”.

Limbo of the third dose in our country is not just a matter of the scarcity of the second component of Sputnik V for the risk group. Over 5.7 million people use the first dose of AstraZeneca and 68% need the second dose as well.

The Minister of Health of Buenos Aires, Fernán Quirós, portrayed it clearly: he said that talking now about the third dose “is a debate that is improvised in Argentina because here today we have to vaccinate the entire population at risk with the second dose “against the Delta variant.

What about health workers, who are among the first to be vaccinated, with the over 80s? “If an increase in the incidence of infections were to appear in them and we begin to realize that there is a defect in the immunity of the vaccine, we would think about itKreplak said the same day, Aug. 10, at the same conference where he discussed business with vaccines. And those who evaluate what he says, precisely, are the members of CoNaIn.

Third dose or booster?

“I think in Argentina vaccination should be reinforced in immunocompromised groups, which do not have the same immunogenic response to the vaccine. And also to those who have received Sinopharm. We’ll have to continue to see how long the antibodies last for the rest of the vaccines and when a booster is warranted. And there, indeed, it would not be a third dose but, precisely, a booster. In addition, studies are underway for the simultaneous application of the vaccine against influenza and the coronavirus, “he says. Bugle Liliana Vazquez, who is part of the Argentine Society of Infectology.

The concepts of third dose, booster or annual dose, have totally diffuse borders. Will the Covid be the new flu? Will it be administered every year and would that stop talking about a third or fourth injection? For Lautaro de Vedia, infectologist at Muñiz hospital, yes.

“You have to understand that the flu has new strains every year, which are defined by the WHO (World Health Organization) in March for our hemisphere. The 2021 vaccine does not work for 2022. It is a new vaccine. a third dose or a booster. It is also not repeating immunization schedules. If the Covid mutates so much that it becomes another strain (remember the difference with variants), a new vaccine may be needed each time. I think this is what will happen with the coronavirus “, explains the infectious disease specialist.

López agrees that “The Covid will be the new flu” and, concerning those who were vaccinated first, it is said that “they are still protected” and that it is not possible to define today whether, in the event that they receive a third dose in the future, it will be the same brand or not.

Third dose: when crossing the pond or the mountain range

Some Latin American countries are just starting their vaccination, or have just stepped up, as is our case. Others are already applying a third dose to at-risk groups. And they are neighbors: Chile and Uruguay.

This, for the WHO, it’s a controversial decision. Tedros Adhanom Ghebreyesus, the director general of this body, opposes the “Inequalities” in the distribution of vaccines.

“We cannot and must not accept that countries which have already used the majority of vaccines use even more doses, because the most vulnerable countries remain unprotected,” he said. These countries do this for the Delta variant.

He called on states that begin to apply booster doses to immunosuppressed groups – as they have also done from Israel to Russia, via the UK – that wait at least two months. A sort of “time window” for at least 10% immunity to be achieved in each country with the current distribution of vaccines.

In most cases of the third dose, this is countries that have applied Sinovac, whose effectiveness in preventing contagion and serious illness has been called into question by recent studies.

Chile has one of the highest vaccination rates on the continent. It is the second country in the region to launch a vaccination campaign to inoculate a third dose.

Since last week, Chileans who have received the full cycle of the Chinese Sinovac vaccine can receive the booster dose. The schedule is organized by age and date of second dose, as announced by health authorities, starting with the elderly. Despite doubts about this brand of vaccines, the Chilean government clarified that the strengthening is due “to The risks of Delta and studies which show that the immunity of vaccinated people wanes over the months “.

The efficacy of Sinovac – which is not applied in Argentina – to prevent symptomatic infections decreased by 5% compared to June. Pfizer’s vaccine, the second most widely used in the South American country, reduced its effectiveness by 3%. The booster will only be applied, primarily with AstraZeneca and Pfizer, to people vaccinated with Sinovac. Chile vaccinated 88% of the population with one dose and 82% with both doses. About 72% received the Chinese vaccine.

At the end of July, Uruguay, another leading country in vaccination in the region, announced the third dose since mid-August to those who have received the Chinese vaccine and to those who have the Pfizer or AstraZeneca vaccine, but who are at risk. . groups (these will receive a third from Pfizer).

Unlike other countries, Uruguay is already talking about a fourth dose for people with moderate and severe immunosuppression due to different diseases, such as cancer or treatments that include corticosteroids which lower the defenses. 73% of Uruguay’s population – over 3 million – have one dose, and 65% have already received both.

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