COVID-19 vaccines have been shown to be highly effective in preventing infection, severe illness, and death if a person is exposed to the coronavirus. Its benefits have changed the course of the pandemic despite the emergence of priority variants of the coronavirus such as Delta: today the majority of people who acquire the infection are those who are not yet immunized. But since inoculants are not 100% effective in prevention, some people who are already fully vaccinated may have the infection because the community circulation of the coronavirus still persists.
In Argentina, a report from the ANLIS / Malbrán Institute, which depends on the Ministry of Health of the Nation, detailed What are the variants of the coronavirus that affect today people who have not yet been vaccinated and those who already have the complete scheme. The study is part of the genomic surveillance of the coronavirus carried out by the group of researchers made up of Carla Voto, Elsa Baumeister, Carlos Giovacchini, and Josefina Campos, among others.
“After the start of the vaccination plan in the country, it began to request that in any confirmed case of COVID-19 it be registered if the person was vaccinated. In our national reference laboratory, samples from these patients are received along with those from others who have only one dose and those who have not yet been vaccinated ”, explained to Infobae Dr. Josefina Campos.
Since the start of the pandemic in March last year, More than 5.3 million confirmed cases of COVID-19 and more than 116 thousand deaths have been reported in Argentina. The ANLIS / Malbrán Institute report took into account the samples of patients with COVID-19 between last January and until October 23 as part of the genomic surveillance of the evolution of the virus.
In this context, it was reported that a total of 3,960 cases of COVID-19 that were studied had a history of vaccination. Within these cases, 1,791 cases had received the application of the first dose of vaccine and 2,169 cases occurred after the application of the second dose. Within the group of people with a complete vaccination scheme, the report included the results of the genomic sequencing of 1,854 cases analyzed.
The researchers found that 54.2% of fully vaccinated people had been infected with the Gamma variant of the coronavirus. 17.8% had the Delta variant. Then followed Alpha (3.5%), Lambda (20%), and Mu (0.3%). That analysis included people who had received both doses and who had passed at least 21 days from the date of vaccination and the date of sampling.
Meanwhile, among 3,436 COVID-19 cases that were not immunized and that were analyzed, the researchers detected that 58.6% had the Gamma variant. Delta was in 7.5% of those cases, Alpha (6%), Lambda (18.5%), and Mu (0.4%). “The results of the report allowed us to know that the proportion of the coronavirus variants that affect the unvaccinated is quite similar to that of the variants acquired by the unvaccinated. Of course, it must be taken into account that the cases of immunized people who acquire the infection are rare within the total number of cases that are sequenced ”, clarified Dr. Campos.
The second wave of the pandemic in the country – from March to June – passed. There was a sustained decline in COVID-19 cases for 20 weeks, but during the previous five weeks there was a slight upward trend with increasing frequency of Delta variant detections. The Delta variant of the coronavirus is already detected in more than 80% of the samples, especially in the City of Buenos Aires, province of Buenos Aires, and Córdoba.
“With the full sequencing of samples from confirmed COVID-19 cases, we have observed a clear increase in the circulation of the Delta variant. We know that the Delta variant is more transmissible than others and that it increases the risk of hospitalization if the person is not vaccinated ”, Campos pointed out. The researcher said that they are already conducting another study that will evaluate the effectiveness of vaccines in the context of the variants that are now circulating in the country.
According to Dr. Humberto Debat, a researcher in molecular virology at the National Institute of Agricultural Technology (INTA) and a member of the Proyecto País consortium that also does genomic surveillance and depends on the Ministry of Science, Technology and Innovation, “It is important that we now have the results of this report from the ANLIS / Malbrán Institute to know which are the variants of the coronavirus that have been detected in people with the complete vaccination scheme in the country.”
The expert added in the dialogue with Infobae: “As different variants have circulated in South America compared to the Northern Hemisphere, such as Lambda and Mu, and there was a predominance of Gamma, the new data suggests that there would be no partial escapes to the protection of vaccines against severe cases and deaths so far . With the passage of time, the infections could become largely due to the Delta variant. For this reason, it is necessary to continue monitoring the high effectiveness of vaccines in the country against this variant ”.
Consulted by Infobae, Javier Farina, member of the Argentine Society of Infectology and head of infectology at the Hospital de Alta Complejidad Cuenca Alta, in Cañuelas, province of Buenos Aires, commented: “In Argentina, there was a predominance of the Gamma variant between February and last August. There was also circulation of Lambda, which has been little detected in the Northern Hemisphere. Now Delta is predominant as is also the case in other countries in South America and previously in the Northern Hemisphere ”.
In addition, Farina pointed out: “As has happened in all regions of the world, vaccines provide high protection against the coronavirus. But with the emergence of the variants of the coronavirus, cases of those vaccinated with the infection began to be registered. This reinforces the importance of remembering that vaccination must continue to be accompanied today by preventive measures such as the use of the chinstrap, distancing, and permanent and cross ventilation when a person is in closed spaces with non-cohabitants ”.
On November 17, the head of the Argentine Health portfolio, Carla Vizzotti, announced that, faced with the possibility of the growth of the Delta variant and to prepare for the fall, “The entire population is going to receive a reinforcement, it has already started with the health personnel and with those over 70 years old according to the provincial plans. An immunity boost is clearly needed ”.
In the United States, the Centers for Disease Control and Prevention (CDC) are also monitoring the status of infections in already vaccinated people. “People who are fully vaccinated with an infection are less likely to develop a serious illness than those who are not vaccinated and have COVID-19,” they recently clarified.
When fully vaccinated people become infected and develop symptoms, they develop fewer severe cases than in unvaccinated people. This means that they are much less likely to be hospitalized or die than unvaccinated people. It is also known that people who contract the coronavirus after being vaccinated can also be infecting others. Therefore, its isolation is important to avoid the circulation of the virus and protect others.