COVID-19 Antibody Levels among Various Vaccination Groups, One-Year Antibody Follow-Up in Two University Hospitals from Western and Central Turkey

Various clinical outcomes, reinfections, vaccination programs, and antibody responses resulted from the COVID-19 pandemic. This study investigated the time-dependent changes in SARS-CoV-2 antibody responses in infected and/or vaccinated and unvaccinated individuals and to provide insights into spike and nucleocapsid antibodies, which fluctuate during infectious and non-infectious states. This cohort study was carried out at the Ege University Faculty of Medicine hospital in İzmir (western Turkey) and the Erciyes University Faculty of Medicine hospital in Kayseri (central Turkey) between December 2021 and January 2023, which coincided with the second half of COVID-19 pandemic. The study included 100 COVID-19 PCR-positive patients and 190 healthcare workers (HCWs). Antibody levels were followed up via quantitative anti-SARS-CoV-2 spike and qualitative anti-nucleocapsid immunoassays (Elecsys™). Antibody levels declined after infection but persisted for at least 6-8 months. Individuals who had received only CoronaVac had higher anti-nucleocapsid antibody levels in the early months than those who received mixed vaccination. However, anti-spike antibodies persisted longer and at higher levels in individuals who had received mixed vaccinations. This suggests that combining two different vaccine platforms may provide a synergistic effect, resulting in more durable and broad-spectrum immunity against SARS-CoV-2. The study provides information about the vaccination and antibody status of healthcare workers in the second half of the pandemic and provides valuable insights into the dynamics of antibody responses to COVID-19 infection and vaccination.

[A Marginal Case of Malaria: An Interesting Malaria Story of Cameroon Origin]

Malaria is a serious, contagious infection caused by single-celled parasites. About 200 species of Plasmodium have been described that can cause infection in vertebrates. Five different species of Plasmodium are known to cause infection in humans to date. Infection with more than one type of pathogen is called coinfection. This type of infections can be caused by different species of the same genus, as well as by different species. Malaria coinfections are mostly caused by the combination of Plasmodium vivax and Plasmodium falciparum. In this study, a case of malaria admitted to the hospital and diagnosed was presented. Thin smear blood preparations were prepared from the peripheral blood of a 54 year-old Republic of Türkiye citizen male patient who applied to the emergency department with fever and chills. The preparations were stained with Giemsa and examined under a microscope with a x 100 objective, and trophozoite and gametocyte forms belonging to Plasmodium genus were determined. As a result of probe-based quantitative real-time polymerase chain reaction (qRt-PCR) study with primers specific to Plasmodium vivax, Plasmodium malariae, Plasmodium falciparum, Plasmodium ovale and Plasmodium knowlesi for definitive species identification, co-infection of P.vivax, P.falciparum, P.ovale and P.knowlesi was detected in the patient. In addition, it was proved that our patient was infected with four different species by conventional PCR study in which five species were studied and then by DNA sequence analysis. On the fourth day of artemether-lumefantrine treatment, the patient's fever response was observed and the trophozoite forms disappeared from the third day in the daily peripheral smear follow-up. Since P.vivax and P.ovale species were also detected after species determination by molecular methods, primaquine 1 x 30 mg tablet was added to the existing drugs for the treatment of hypnozoite forms of the parasite. In recent years, there has been an increase in malaria imported cases, especially after visits to African countries. Such rare cases of malaria coinfection may be encountered during visits to geographies located at the intersection of endemic regions. According to the data of the World Health Organization, maximum attention should be paid to the prevention and prophylaxis protocols from vectors, especially in travels to countries with the highest mortality and morbidity. In co-infection cases similar to our patient, for tertian malaria and tertiary ovale malaria, hypnozoid therapy should not be overlooked. When the insecticide-resistant vectors and drug-resistant Plasmodium strains encountered in recent years are evaluated as a whole, there is a need to develop more effective strategies in the fight against malaria. In addition to microscopic examination, which is accepted as the gold standard, we believe that evaluating molecular studies together in diagnosis is extremely important for the treatment process when hypnozoite periods are considered.