Vaccine co-administration is an important tool with several advantages for public health, among which is the increase of vaccination coverage, as well as economic and logistical benefits. The purpose of this study was to assess and compare the immune response to the COVID-19 first booster dose in healthcare workers (HCWs) who chose co-administration and in HCWs who received only COVID-19 vaccination and to investigate personal opinions about the experience of co-administration. We carried out a retrospective analysis involving two groups of HCWs, both vaccinated with the complete primary cycle and the first booster dose of the COVID-19 vaccine, but one of them was also vaccinated, at the same time as the first booster dose, with the influenza vaccine. Active phone calls were also performed, and specific questions about the onset of side effects and general opinions were asked. A good immune response was found in both two groups without any statistically significant difference in the immune response. No severe reactions occurred in either group. A greater part of the sample was completely satisfied, and they would do it again. Our findings are totally in favor of the co-administration, considering the many positive aspects provided by administering, at the same time, more vaccines.

Severe Acquired Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) infection represents an unprecedented public health problem and, at present, vaccination is the only weapon available to combat the infection. The simplest and most immediate method to quantify the response of the subject's immune system to vaccination and / or infection is the serological assessment of the antibody titer. The objective of our study was 1) to evaluate the presence of antibody responses in a sample of healthcare workers subjected to a complete vaccination course as per ministerial provisions (double dose for negatives and single dose for ex-SARS-CoV subjects -2 positive) with Comirnaty vaccine (Pfizer / BioNTech) 2) evaluate the presence of statistically significant associations for sex, age and previous positive swab. the antibody levels of both nucleocapsid antibodies and anti-Sars-CoV2 Spike antibodies of the study subjects were examined with the electrochemiluminescent immunoassay (ECLIA) method developed by Roche®. The cut-off value, as suggested by the manufacturer, for anti-nucleocapsid antibodies was 1 COI, while the Ig Spike value was 0.8 I / mL. The study sample was stratified by age (≤45 years, 46-55, ≥56 years old), previous positive molecular swab, gender and IgG S1 / S2 values ​​at the completed vaccination course (≤200, ≥200 AU / mL ). Statistical analyzes were carried out with the R software. almost all of the sample (89.45%) showed IgG Spike values> 200 AU / mL with statistically significant associations in relation to sex (greater in females, p≤0.05), to previous swab positivity in the presence of a vaccine dose (n = 44; p <0.001) and at age (with greater antibody response in subjects under 45; p <0.001). The current study confirms what is reported in the literature. In the light of the results obtained, it could be interesting to promote studies that evaluate the antibody titers trend over time a) in women of childbearing age and postmenopausal age b) in particular categories of subjects with chronic degenerative diseases to assess the actual need for doses booster, it being understood that the immune system response is guaranteed by both cellular and humoral immunity and that the antibody titer does not faithfully reflect the protection obtained.

The vaccination of pregnant women against influenza and COVID-19 may reduce the risk of severe illness in both the women of this population and their babies. Although the risks of non-vaccination are more serious than the side effects, maternal immunization is still the least-used method of prevention due to a lack of information leading to concerns about the safety and efficacy of vaccines, resulting in a low prevalence rate among pregnant individuals. Our study investigates vaccination coverage and the knowledge, attitudes and perceptions of COVID-19 in pregnant women at a university hospital. A questionnaire was created with the following three scores: a vaccination propensity score, a knowledge score and a hesitancy score. The first observation in the results was the very low number of immunized women (only 4.7% received their first dose). The main barrier towards vaccination was found to be fear of adverse events. We noticed a low percentage of influenza and diphtheria tetanus pertussis vaccination compared to other studies. Vaccination propensity was higher when healthcare workers educated their patients. As immunization is a crucial part of public health policy, measuring coverage to identify gaps and monitor trends, especially for individuals considered at high risk, and developing new strategies in order to increase awareness of vaccination during pregnancy is particularly timely and relevant.

On 11 June 2021, the Italian Ministry of Health authorized the heterologous vaccination schedule. The goals of our retrospective study were to (a) evaluate the undesirable effects after the administration of Vaxzevria and Comirnaty vaccines; (b) evaluate the antibody response after 28 days from the administration of the second dose; and (c) compare the antibody responses after the homologous and heterologous vaccination regimens. The undesirable effects were collected using a survey; IgG Spike was quantified using the electrochemiluminescence method; the comparison between the antibody responses was carried out using the sample of a homologous vaccine schedule previously analyzed. Pain at the injection site is the most common undesirable effect after the administration of both vaccines (62.1% after Vaxzevria vs. 82.75% after Comirnaty); swelling at the injection site is more frequent after the administration of Vaxzevria than after the administration of Comirnaty: (15.52% vs. 5.17%); headache is more frequent in women than in men for both the vaccination types (p < 0.05); 49.09% of the sample reported IgG Spike ≥ 12,500 U/mL; the antibody titer of the heterologous schedule is higher than that of the homologous vaccination. Our study demonstrated that the undesirable effects after the administration of the second dose are less frequent and less severe than after the administration of the first dose, and that the immunogenicity of the heterologous vaccinations is higher than that of the homologous ones.