Patients suffering from autoimmune inflammatory diseases (AIDs), such as rheumatoid arthritis (RA), systemic lupus erythematosus, spondyloarthropathies, among others, have an increased risk of developing infections, derived from both the immunosuppressed state of the disease and the treatment used1. These are one of the main causes of morbidity and mortality in these subjects2.

Vaccination in patients with AIDs is widely recommended by different clinical practice guidelines against influenza, herpes zoster, Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae, hepatitis A, hepatitis B, human papilloma virus, tetanus, and Neisseria meningitis3,4. However in developed countries such as the United States the vaccination rate against influenza in patients with RA is 45,8%5 while for S. penumoniae it is only 28,5%6. Worldwide the highest vaccination rates are found in France at a rate of 56.5%, whilst in Latin America there are reports in Uruguay of 46.4%, and in Argentina of 36.7%7.

There is little information in Mexico on the adherence of patients with RA and other AIDs to recommended vaccination schedules. One study evaluated adherence by rheumatologists in recommending vaccination to their patients, finding among the 122 professionals consulted that only 50% recommend immunisation against influenza and 36.07% against pneumococcus8. A study in France that evaluated vaccination coverage against influenza and pneumococcus in patients with inflammatory joint diseases on biologic therapy and the factors associated with non-adherence found that rheumatologists recommend vaccination against influenza in 79% of patients and against pneumococcus in 79% of patients, found that rheumatologists recommend vaccination against influenza by 79% and against pneumococcus by 78%, much higher percentages than those recommended by primary care physicians9, but these results present a challenge since the percentage of patients who adhere to the recommendations is even lower. The prevalence of RA patients in Mexico and much of Latin America who comply with the vaccination schedule recommended by clinical practice guidelines is unknown3,4.

In the end, 227 patients were included in the study. Table 1 summarises the characteristics of the population, including demographic data and treatment history.

In the specific questions on influenza vaccination, we initially asked how many patients had current immunisation, i.e., had been vaccinated within the last year, with 71 patients (31.3%) responding affirmatively; we also analysed the distribution of this variable with respect to other independent variables, such as sex, schooling and type of treatment used, with no significant differences between groups. Finally, we studied long-term compliance with continuous influenza vaccination over the last 5 years, with 27 patients (11.9%) reporting having received the influenza vaccine.

Regarding vaccination against S. pneumoniae, only 40 patients (17.6%) received immunisation against this microorganism in the last 5 years; this variable was also analysed by sex, schooling and type of treatment, with no significant differences between groups. The combined protection against pneumococcus (in the last 5 years) and influenza (in the last year) in the same individual was also investigated, with 29 patients (12.8%) fulfilling this condition. The study also asked about the application of other vaccines recommended by the Mexican College of Rheumatology for patients diagnosed with rheumatoid arthritis artritis8, and these data are summarised in Table 210.

Finally, patients who did not comply with the recommended vaccination schedule were asked about the reason(s) for non-compliance; this question had five response options and patients could choose one or more options. The main reason for non-compliance was lack of knowledge about the indication to be vaccinated in 116 patients (51.1%), followed by 98 patients (43.2%), where their rheumatology doctor at some point advised them not to be vaccinated, 38 patients (16.7%) where doctors other than rheumatology also advised against it, finally 29 patients (12.8%) stated that for their own reasons they did not wish to do so, and 23 patients (10.1%) because the institution did not have the vaccines recommended by their doctor.

RA and general patients with AIDs have an increased risk of contracting influenza compared to the general population5 and immunisation is widely recommended and has been shown to be effective in both prevention and reduction of morbidity and mortality. In Mexico, the majority of the population receives a trivalent vaccine with an immunogenicity that has been shown to be optimal in patients treated with any conventional synthetic (sDMARDs) or biological (bDMARDs) disease-modifying drug; except for rituximab, on which there is heterogeneous information, as some authors conclude that it has a lower response in the generation of antibodies11,12; while others show that there are no statistically significant differences in immunogenicity in treatment groups with bDMARDs sDMARDs and combined therapy with bDMARDs and sMARDs, compared to the healthy population; however, a lower rate of immunogenicity against influenza b antigen in the combined therapy group is noteworthy, This study is limited by the small number of participants and the lack of homogeneity with respect to age13. Furthermore, although it is not recommended by clinical guidelines, the suspension of methotrexate two weeks before to two weeks after the application of the vaccine improves the response12,14.

The present study found that 31.3% of patients surveyed had been vaccinated within the last year, a rate below those reported in the United States5 and in Latin America compared with Uruguay and Argentina7.

In the bivariate analysis of our study, we found no significant differences related to adherence in relation to sex, schooling or type of treatment, although patients with postgraduate studies had higher adherence rates.

As with influenza, patients with RA have an increased risk of infection by S. pneumoniae, and the disease is also more severe than in the rest of the population15. In Mexico, two vaccines are available: 23-valent and 13-valent4. In terms of immunogenicity, it has been evaluated with different treatment modalities, in terms of sDMARDs, especially methotrexate16 with antibody levels that persist for up to 10 years. In the case of patients treated with bDMARDs, studies have shown that they do not significantly affect immunogenicity17, with no significant differences between anti-TNF, tocilizumab or rituximab18.

In this study, 17.6% compliance with pneumococcal vaccination was found, lower than that reported in other series and, as with influenza, with non-significant differences in relation to sex, schooling and the treatment strategy employed. It is important to note the low percentage of combined vaccination, as only 12.8% had it, a topic that has not been addressed in other studies.

This research attempts to highlight as a secondary objective the causes for non-compliance with the vaccination schedule by patients, highlighting that the majority 51.1% were unaware that they belonged to a population with specific vaccination indications, and that another large percentage at some point in the evolution of the disease asked their rheumatologist who recommended that they not be vaccinated. Immunisation recommendations have been strengthened by scientific evidence over the last two decades, as there was no research on the immunogenicity and safety of immunisation in these patients.

A French study with a design very similar to the present one found that the main reasons for non-vaccination were forgetfulness and concern about adverse effects, perhaps related to higher rates of adherence on the part of doctors in recommending vaccination and patients in administering it9. A recent publication in northern Mexico asking patients about their knowledge of the influenza vaccine showed that 26.7% of those who had not been vaccinated and 13.5% of those vaccinated considered it unsafe and ineffective, 7.6% said it was not necessary and 11.7% considered that the influenza vaccine could worsen the symptoms of their underlying rheumatic disease19. Based on this, we can conclude that there is very heterogeneous information, especially in the way in which research addresses patient knowledge and the reasons for non-compliance with vaccination schedules; patient ignorance is an important factor in Mexico. Our study addresses an aspect not taken into account in other questionnaires on the role that physicians play in discouraging vaccination, requiring extensive campaigns throughout the country to educate medical personnel on the correct implementation of this practice.

This study has limitations due to the number of patients included, the selection bias, since the study was carried out during the COVID-19 pandemic, which meant that most of the patients surveyed were those receiving intravenous biological therapy. Patients with other treatment modalities only came for drug reformulation and this made it difficult for them to be included. In addition, the hospital where the research was carried out is a national reference centre attended by people with severe RA, of long standing and with failure of several lines of treatment.

In conclusion, this research reveals worrying coverage figures, with opportunities to improve and reinforce the adherence of RA patients to vaccination, emphasising education as a fundamental pillar and opening up opportunities for new studies such as the one cited by Figueroa et al.19, in which knowledge, fears and apprehensions are investigated, not only in patients, but also in doctors.

The authors have no conflict of interests to declare.