May 16, 2022 11:49 am

When does the third dose of the vaccine take effect?



Spain is currently totally dedicated to the campaign of booster dose vaccination of vaccines against Covid-19. According to the latest data from the Ministry of Health, 90.7% of the population over 70 years of age, 88.9% of those over 60, 78.8% of those over 50 and 66.7% of those over 40, already have the third dose of the drug. And little by little other age groups go to the centers authorized for vaccination to receive their corresponding dose.

Vaccination is becoming more and more necessary. Spain, like much of Europe, is mired in sixth wave of the pandemic. The accumulated incidence in most of the autonomous communities exceeds 500 cases per 100,000 inhabitants, which places our country in high risk.

Vaccines have been shown to be effective in preventing severe illness and death from coronavirus, although not as effective in preventing infection. However, this third dose or booster dose, in the case of those vaccinated with Janssen, is necessary since, as several studies confirm and the ECDC confirmed, the effectiveness of the injection, close to 80%, slightly decays over time, so that acquired immunity is being lost.

In addition, it seems that the third dose, at least of the Pfizer/BioNTech vaccine, is effective against Omicron, the South African variant causing this increase in infections. In fact, a study published by the journal ‘Science’ shows that this booster dose can offer a sufficient level of protection against the disease caused by this new variant of the coronavirus.

The study is in line with a study recently published in ‘Cell’ that pointed out the need for a booster dose of the Covid-19 vaccine from Modern or Pfizer to provide immunity against the Omicron variant of SARS-CoV-2 because they did not produce antibodies capable of recognizing and neutralizing the Omicron variant.

But when does this booster dose take effect?

Immune response after booster dose

Data from a study
posted on medRxiv
show that the immune system generates a large antibody response six to ten days later of the booster dose against coronavirus.

According to this research, carried out by scientists at Northwestern University and in which 33 people participated, the levels of antibodies that are achieved after the booster dose exceed the levels documented after natural infection of SARS-CoV-2, with vaccination with two doses or after natural infection and vaccination with a single dose.

Apparently, although people with two doses have antibodies needed to prevent serious illness or death by coronavirus, after administering the booster dose against Covid-19, antibody levels are multiplied by 25, going from 4.4µg/mL to 101.6µg/mL. Thus, the mean antibody concentration after the booster dose was significantly higher. All participants responded to reinforcement with a increased antibodies.

All in all, the results of this study indicate that the reinforcements of the mRNA vaccines, those of Pfizer and Moderna, generate large antibody responses in healthy adults. However, the researchers note that limitations of the study include a small sample size, a short period of time and the absence of cellular immunity measures. Although decreased antibodies may contribute to breakthrough infections, it is important to investigate the effects of boosters on cell-mediated immunity.

See them

Comments (0)

Leave a Reply

Your email address will not be published.