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Percorrer Departamento de Doenças Infecciosas por Domínios Científicos e Tecnológicos (FOS) "Ciências Médicas::Outras Ciências Médicas"
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- Do COVID-19 and Influenza vaccines influence susceptibility to other respiratory viruses? A population based studyPublication . Almeida Santos, João; Gomez, Verónica; Guiomar, Raquel; Verdasca, Nuno; Gomes, Licínia; Machado, Ausenda; Rodrigues, Ana PaulaIntroduction: Studies have raised concerns that Influenza and COVID-19 vaccination may influence susceptibility to other respiratory viruses (ORV), potentially increasing the risk of non-target infections. This challenges a key assumption of test-negative design studies—that vaccines do not affect the risk of other infections within the same clinical syndrome. Nevertheless, current evidence remains inconclusive. This study aimed to evaluate the association between COVID-19 and influenza vaccination and the risk of non-influenza/COVID-19 respiratory virus infections. Methods: Test-negative design (TND) study using Portuguese data from a primary care vaccine effectiveness study (VEBIS Primary Care study) between October/2022-April/2025. Data on influenza/COVID-19 vaccination status, age, sex and chronic conditions were collected. Samples were tested by RT-PCR for influenza, SARS-CoV-2 and ORV. Patients with laboratory-confirmed influenza/COVID-19 infection were excluded. Logistic regression estimated adjusted odds ratios (aOR) of being vaccinated among cases (ORV positive) and controls (pan-negative). Results: Of the 1096 patients included, 4.5% received the COVID-19 vaccine, 5.9% the influenza vaccine, 13.3% both, and 76.3% neither. Human Rhinovirus (44.2%), human Coronavirus (14.6%) and Respiratory Syncytial Virus (14.1%) were the viruses more frequently identified. Individuals 65+ exhibited significant lower odds of infection with ORV (OR=0.45, 95%CI:0.25-0.81) compared to younger age group (<18yo). Vaccination status, including influenza only (aOR=1.01, 95%CI:0.59‐1.72), COVID only (aOR=0.88, 95%CI:0.48‐1.59), and both vaccines (aOR=1.38, 95%CI:0.92‐2.06), were not associated to ORV infection risk. Conclusions: Our results suggest that vaccination status—whether for influenza, COVID-19, or both—was not significantly associated with the risk of ORV infections. This supports the use of test-negative controls for influenza/COVID-19 within the same clinical syndrome, as it upholds a key TND assumption of no association between vaccination and risk of non-target infections. While mechanisms such as reduced cross-protection from natural infection or potential vaccine-induced cross-immunity have been proposed, our findings reinforce the validity of the primary methodological assumption rather than suggesting evidence for these alternative effects.
- The spread of Aedes albopictus in Portugal: an update of its geographic and seasonal distributionPublication . Costa Osório, Hugo; Soares, Patricia; Freitas, R.; Fernandes, R.; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria JoãoOver the last two decades, the invasive mosquito Aedes albopictus has spread across Europe. Portugal was the last country in southern Europe to report this species, which was first detected in 2017 under the National Vector Surveillance Network—REVIVE. Despite all the measures taken, its distribution has increased rapidly and in 2023, it was introduced in Lisbon, a major urban centre. As Ae. albopictus is a competent vector for dengue, Zika and chikungunya viruses, monitoring its geographic distribution and seasonal dynamics is crucial for public health risk assessment.
- Wolbachia Screening in Aedes aegypti and Culex pipiens Mosquitoes from Madeira Island, PortugalPublication . Fernandes, Rita; Melo, Tiago; Marques Zé-Zé, Líbia Maria; Campos Freitas, Inês; Silva, Manuel; Dias, Eva; Santos, Nuno C.; Gouveia, Bruna R.; Seixas, Gonçalo; Costa Osório, HugoSimple Summary: Mosquitoes can spread serious diseases like dengue and West Nile virus. On Madeira Island, two mosquito species—Aedes aegypti and Culex pipiens—are present and may pose a risk to public health. Scientists are exploring new ways to control these mosquitoes using a natural bacterium called Wolbachia, which can reduce a mosquito’s ability to transmit viruses and even lower mosquito populations. However, for these methods to work, it is important to know first if the mosquitoes in the area already carry this bacterium. In this study, we tested Ae. aegypti and Cx. pipiens from Madeira for Wolbachia. Wolbachia was absent in all 100 Ae. aegypti tested but present in all 40 Cx. pipiens. We also found that the Wolbachia in Cx. pipiens belonged to a group commonly seen in other parts of the world. These results are important because they help us understand which mosquito control strategies might work in Madeira. Specifically, if scientists want to use Wolbachia to control Ae. aegypti on the island, they would need to introduce it artificially. This information can help improve public health efforts and reduce the risk of mosquito-borne diseases in the region.