The Department of Health (SES) should publish in the coming days a new guideline to municipalities regarding vaccination with a new dose for the elderly aged 80 years and over. Re-application is recommended four months after the booster dose. If the elderly person is overdue for another dose, he/she must first complete the schedule (primary or booster), within the deadlines referring to the vaccine received.

Municipalities are already authorized to start applying this second booster, according to the availability of doses. New transfers are planned by the SES, according to future receipts of lots distributed by the Ministry of Health.

In Rio Grande do Sul, the total population in this age group over 80 years is estimated at 326 thousand people. Of these, 74% (about 243,000 individuals) have already had the booster dose. However, there is still a significant number of people with delayed doses. Approximately 26,000 did not even take the first dose, another 8,300 had the first dose, but they are late with the second dose, in addition to another 63,000 who are late for the booster.

Among those who have already taken the booster dose, 180,000 people would already be on time to make this fourth dose and another 28,000 arrive within four months until the end of the first week of April.

Increase in cases and deaths in people aged 80

The monitoring of cases and deaths of covid-19 by the SES points to an increase in the incidence in the age group over 80 years of age, which demonstrates a trend of loss of protection in properly vaccinated elderly people after a few months. Some studies have shown a reduction in the effectiveness of vaccines against coronavirus after 3 to 4 months of application and more pronounced after 5 months. The reduced effectiveness of vaccine platforms in the elderly can be explained, in part, by the natural aging of the immune system (immunosenescence).

According to a survey by the State Health Surveillance Center (Cevs), the age group over 80 years old was the one with the highest record of hospitalizations and deaths from covid-19 this March. Individuals of these ages accounted for 34% of hospitalizations and 56% of deaths in the period. In absolute numbers, this represented 192 hospitalizations (out of a total of 558) and 71 deaths (out of a total of 128).

These percentages have increased in recent months. At the end of December 2021, for example, people aged 80 and over accounted for less than 20% of hospitalizations and approximately 25% of deaths.

Vaccines available

The Technical Note of the Extraordinary Secretariat for Combating Covid-1 of the Ministry of Health that deals with this expansion of the scheme (number 20 of 2022) establishes that the vaccine to be used for the dose of this new booster should preferably be Pfizer (from the messenger RNA type) or, alternatively, viral vector vaccines (Janssen or AstraZeneca).

Reinforcement reduces the chance of death by up to 17 times

This week, the Department of Health released a new analysis of the relationship between vaccination and deaths from Covid-19. According to the calculation, an elderly person with a booster dose has 17 times less risk of death from coronavirus when compared to the individual without any dose. In the population aged 40 to 59 years, this protection represented 14 times less chance of death for the person with the booster dose in relation to the person not vaccinated.

The data indicate that the risk of death is significantly higher for the unvaccinated, noting that the more complete the vaccination schedule, the lower the recorded mortality.

Experiences in other countries

The announcement of this new dose for this audience pondered some experiences in other countries recently. Preliminary findings from studies carried out in Israel showed that, after the application of a second booster dose (fourth dose), there was a five-fold increase in antibodies after one week. Based on this analysis, the Israeli government started on the day in January of this year the application of the fourth dose in individuals aged 60 years and over, after a 4-month interval from the application of the third dose.

In Chile, the government started in February the vaccination with the second booster dose (fourth dose) against covid-19 for people aged 55 and over, due to the increase in the number of cases related to the Ômicron variant and considering the reduced effectiveness in more vulnerable groups.

Fourth dose for immunocompromised people

In Brazil, since December last year, there is already a four-dose regimen guidance, indicated for immunocompromised people aged 18 years or older, who received three doses in the primary regimen (first and second dose in the primary regimen plus an additional dose ). In these cases, the booster (fourth dose) takes place after four months of the additional dose.