University of São Paulo: Coronavac generates satisfactory antibody response in patients with autoimmune rheumatic diseases

FORPatients with autoimmune rheumatic diseases (ARD) had a moderate antibody response to Coronavac after taking the second dose of the vaccine, a response considered satisfactory in 70% of them. The vaccine also demonstrated a good safety profile for this group. These are some of the conclusions of a prospective study led by the Faculty of Medicine of USP (FMUSP).

As expected by the characteristic of the disease, six weeks after the second dose there was a lower rate of seroconversion ( generation of IgG antibodies ) in the group with rheumatic disease (70%) compared to the control group (95%) . The research also pointed out that the identification of neutralizing antibodies – capable of blocking the entry of the virus into cells, preventing viral replication and illness -, was lower in patients with ARD. 56% of them tested positive for these antibodies, against 79% of those in the control group.

The main objective of the study was to evaluate humoral immunogenicity – which is the ability of a substance to provoke an immune response with the production of antibodies by the patient. We also sought to contribute more data on the safety of the vaccine in the studied group.

Volunteers (910 patients with autoimmune rheumatic diseases and 182 healthy adults, age and gender matched) received the two doses of vaccine within a 28-day interval and were followed for 80 days through face-to-face assistance, telephone, instant messaging and and -mail.

Previous work investigating the efficacy of messenger RNA vaccines (such as Pfizer and Moderna) against covid-19 in patients with ARD showed slightly reduced responses, but the results were limited by the absence of a control group and the small number. of patients with ARD. Furthermore, the production of neutralizing antibodies has not necessarily been evaluated.

According to Eloísa Bonfá, a rheumatologist and professor of the Clinical Medicine Department at FMUSP, immunocompromised patients are more likely to develop infectious diseases due to immune dysregulation and treatment regimens for the respective diseases. “For these reasons, we expect a reduced action of the vaccine”, he explains to Jornal da USP . “When we started the work, our intention was to investigate what kind of damage this lesser protection could cause.”

Volunteer Profile
The ARD and control groups were of similar ages (51 and 50 years, respectively) and women were the majority (77%) in both groups. The population of patients with autoimmune rheumatic diseases represented eight systemic diseases, such as rheumatoid arthritis, lupus, systemic sclerosis, idiopathic inflammatory myopathies, among others.

A total of 348 patients with ARD were undergoing continuous treatment with prednisone and 573 were using immunosuppressive drugs (such as methotexate and leflunomide, among others). In addition, 321 of them were being treated with biological therapies: 15% were using tumor necrosis factor (TNFi) inhibitors and the remainder using other types of drugs.

Analyzes performed 28 days after the application of the first dose show that a minority of participants developed IgG-type antibodies in both groups soon after the first dose (19% in patients with ARD and 35% in controls). “With the application of the second dose, this number practically triples, that is, it reaches 70% in patients with ARD and 95% in the control group”, emphasizes Ana Ribeiro, assistant in the discipline of rheumatology at FMUSP and the first author of the study. “This shows the importance of the second dose to ensure protection.”

Regarding the production of neutralizing antibodies, she says that “there is a difference between the groups, but the immune response induced by the vaccine manages to block the virus binding in the cell by a little more than 30%, which is the minimum acceptable in the literature, in majority.”

As for vaccine-related adverse effects, most were mild. The most frequent side effects reported after the first dose in both groups were arm pain, drowsiness and headache. General reactions were reported more frequently in patients with ARD, including arthralgia (joint pain), back pain, malaise, nausea and sweating. After the second dose, patients with rheumatic diseases reported less itching at the application site and more sweating.

Eloísa warns that immunosuppressed patients also have more difficulty in eliminating the virus from the body, which can facilitate mutations and, consequently, the appearance of new variants. “In these people, sars-cov-2 has the opportunity to live longer, multiply and create other strains”, he says. “Caring for this group is to benefit not only them, but the population as a whole.”

Next steps
Some volunteers (30% of patients with rheumatic diseases) did not achieve satisfactory protection against sars-cov-2. This number was around 5% in healthy patients. According to the researchers, this usually happens in elderly patients. “We also know that the use of some medications impair a better response of the body to the pathogen”, explains Ana Ribeiro.

Among immunosuppressive drugs, methotrexate and mycophenolate mofetil had a negative impact on immunogenicity. Abatacept and rituximab caused more damage in those treated with biological products.

Eloísa told Jornal da USP that this research opened up several work fronts. “In one of them, we are going to study the specificity of each pathology because, although they form a large group, each disease can cause better or worse response to vaccines.”

In November of this year, the researchers intend to carry out a new task force to test the serology of the volunteers again, in addition to carrying out an epidemiological surveillance with the aim of investigating new cases of covid-19 in this population. “If that happens, we can think of different treatment strategies, such as a quick booster or even the application of a third dose of Coronavac”, concludes the doctor.

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