Developing COVID-19 vaccine recommendations during the pandemic: The experience of Serbia's Expert Committee on Immunization

Vaccine Effectiveness against SARS-CoV-2 Infection during the Circulation of Alpha, Delta, or Omicron Variants: A Retrospective Cohort Study in a Tertiary Hospital in Serbia

The COVID-19 pandemic prompted rapid vaccine development and deployment worldwide. Despite widespread vaccination efforts, understanding the effectiveness of vaccines in hospitalized patients remains a critical concern. This retrospective cohort study, conducted at a tertiary healthcare centre in Serbia, tracked patients hospitalized during different waves of COVID-19 variants-Alpha, Delta, and Omicron. Data collection included demographics, comorbidities, symptoms, and vaccination status. Among 3593 patients, those with prior exposure to COVID-19 cases or hospital treatment showed higher positivity rates. Symptom prevalence varied across waves, with coughs persisting. Patients without chronic diseases were more frequent among those testing negative. Vaccine effectiveness varied, with Sinopharm demonstrating a 45.6% effectiveness initially and Pfizer-BioNTech showing an effectiveness of up to 74.8% within 0-84 days after the second dose. Mixed-dose strategies, notably Sinopharm as a primary dose followed by a Pfizer-BioNTech booster, suggested increased protection. Despite substantial vaccination availability, a significant portion of hospitalized patients remained unvaccinated. This study underscores the dynamic nature of vaccine effectiveness and advocates for booster strategies to address evolving challenges in combating COVID-19, particularly in hospitalized patients.

SARS-CoV-2 IgG antibody status in unvaccinated and 2-dose vaccinated Indonesians by AstraZeneca

Indonesia began deploying a COVID-19 vaccine in January 2021, prioritising vaccination for high-risk groups such as healthcare workers, the elderly and those with comorbidities, and ending with the general public due to limited vaccine availability. Our study aimed to evaluate antibody response in Indonesians who had received two doses of the vaccine vs. those who had not. The study design was a cohort study involving 46 unvaccinated people and 23 people who had received the second dose of the AstraZeneca vaccine in three months. Methods used for the qualitative and quantitative detection of IgG antibodies included rapid RI-GHA and ELISA tests. Findings showed that positive IgG antibodies qualitatively detected by the rapid RI-GHA test were significantly higher in those vaccinated (60.9%) than in unvaccinated people (26.1%). Using the ELISA assay, all vaccinated individuals qualitatively showed positive antibodies (cut-off ≥4.33 BAU/ml), and the average quantitative titer of anti-SARS-CoV-2 s-RBD IgG was significantly higher in vaccinated (157.06±238.68 BAU/ml) than in unvaccinated (51.90±87.60 BAU/ml) individuals. Some unvaccinated individuals with no history of infection were found to have anti-SARS-CoV-2 antibodies that may have been previously asymptomatic, although their mean antibody titers were certainly lower than those in the 2-dose group. Approximately 56% of vaccinated individuals had antibody titers above 60 BAU/ml as a cut-off for protective threshold, a significantly higher proportion than unvaccinated individuals. In conclusion, vaccination with two doses AstraZeneca increased anti-SARS-CoV-2 antibodies which resulted in enhanced immunity against symptomatic COVID-19.

Molnupiravir compared to nirmatrelvir/ritonavir for COVID-19 in high-risk patients with haematological malignancy in Europe. A matched-paired analysis from the EPICOVIDEHA registry

INTRODUCTION

Molnupiravir and nirmatrelvir/ritonavir are antivirals used to prevent progression to severe SARS-CoV-2 infections and decrease hospitalisation and mortality rates. Nirmatrelvir/ritonavir was authorised in Europe in December 2021, whereas molnupiravir is not yet licensed in Europe as of February 2022. Molnupiravir may be an alternative to nirmatrelvir/ritonavir because it is associated with fewer drug-drug interactions and contraindications. A caveat for molnupiravir is the mode of action induces viral mutations. Mortality rate reduction with molnupiravir was less pronounced than that with nirmatrelvir/ritonavir in patients without haematological malignancy. Little is known about the comparative efficacy of the two drugs in patients with haematological malignancy at high-risk of severe COVID-19. Thus, molnupiravir and nirmatrelvir/ritonavir were compared in a cohort of patients with haematological malignancies.

METHODS

Clinical data from patients treated with molnupiravir or nirmatrelvir/ritonavir monotherapy for COVID-19 were retrieved from the EPICOVIDEHA registry. Patients treated with molnupiravir were matched by sex, age (±10 years), and severity of baseline haematological malignancy to controls treated with nirmatrelvir/ritonavir.

RESULTS

A total of 116 patients receiving molnupiravir for the clinical management of COVID-19 were matched to an equal number of controls receiving nirmatrelvir/ritonavir. In each of the groups, 68 (59%) patients were male; with a median age of 64 years (interquartile range [IQR] 53-74) for molnupiravir recipients and 64 years (IQR 54-73) for nirmatrelvir/ritonavir recipients; 56.9% (n=66) of the patients had controlled baseline haematological malignancy, 12.9% (n=15) had stable disease, and 30.2% (n=35) had active disease at COVID-19 onset in each group. During COVID-19 infection, one third of patients from each group were admitted to hospital. Although a similar proportion of patients in the two groups were vaccinated (molnupiravir n=77, 66% vs. nirmatrelvir/ritonavir n=87, 75%), more of those treated with nirmatrelvir/ritonavir had received four vaccine doses (n=27, 23%) compared with those treated with molnupiravir (n=5, 4%) (P<0.001). No differences were detected in COVID-19 severity (P=0.39) or hospitalisation (P=1.0). No statistically significant differences were identified in overall mortality rate (P=0.78) or survival probability (d30 P=0.19, d60 P=0.67, d90 P=0.68, last day of follow up P=0.68). Deaths were either attributed to COVID-19, or the infection was judged by the treating physician to have contributed to death.

CONCLUSIONS

Hospitalisation and mortality rates with molnupiravir were comparable to those with nirmatrelvir/ritonavir in high-risk patients with haematological malignancies and COVID-19. Molnupiravir is a plausible alternative to nirmatrelvir/ritonavir for COVID-19 treatment in patients with haematological malignancy.

Myotonic dystrophy type 1 in the COVID-19 era

INTRODUCTION

Myotonic dystrophy type 1 (DM1) is the most prevalent muscular dystrophy in adults. People with DM1 might represent a high-risk population for respiratory infections, including COVID-19. Our aim was to evaluate the characteristics of COVID-19 infection and vaccination rate in DM1 patients.

METHODS

This cross-sectional cohort study included 89 patients from the Serbian registry for myotonic dystrophies. Mean age at testing was 48.4 ± 10.4 years with 41 (46.1%) male patients. Mean duration of the disease was 24.0 ± 10.3 years.

RESULTS

COVID-19 infection was reported by 36 (40.4%) DM1 patients. Around 14% of patients had a more severe form of COVID-19 requiring hospitalization. The severity of COVID-19 was in accordance with the duration of DM1. A severe form of COVID-19 was reported in 20.8% of patients who were not vaccinated against SARS-CoV-2 and in none of the vaccinated ones. The majority of 89 tested patients (66.3%) were vaccinated against SARS-CoV-2. About half of them (54.2%) received three doses and 35.6% two doses of vaccine. Mild adverse events after vaccination were recorded in 20.3% of patients.

CONCLUSIONS

The percentage of DM1 patients who suffered from COVID-19 was like in general population, but with more severe forms in DM1, especially in patients with longer DM1 duration. The study indicated an overall favorable safety profile of COVID-19 vaccines among individuals with DM1 and its ability to protect them from severe COVID-19.

Guillain-Barre Syndrome Followed by Covid-19 Infection, Vaccination and Other Precipitating Factors during the Pandemic

Background and Aims

Guillain-Barré syndrome (GBS) is usually triggered by an infection. Vaccination is mentioned as a possible trigger in a small number of GBS cases. The aim of this study was to notice GBS distinctness provoked by various triggers during the COVID-19 pandemic.

Material and Methods

A total of 109 GBS patients were divided into three groups, respectively: COVID-19 infection associated (19 patients), COVID-19 vaccination associated (16 patients) and precipitated by some other factors (74 patients). We compared the clinical, neurophysiological and laboratory characteristics of these three groups.

Results

Neither were differences recorded in the age of the patients of these three groups at the time of illness, nor in the number of days from the precipitating factor to the onset of symptoms. There were no clinical differences between groups related to severity of the disease or patients' recovery. The only clinical difference was observed in relation to facial nerve bilateral affection because it was significantly higher in the post-vaccination group. According to neurophysiological findings, demyelinating form dominated in all three groups.

Conclusion

Clinical characteristics, electrophysiological findings and laboratory characteristics did not differ significantly in Guillain-Barre syndrome followed by COVID-19 infection, vaccination and other precipitating factors during the pandemic. The bilateral involvement of facial nerves was significantly higher in the post-vaccination group. Most of these cases had a mild form of the disorder-distal paresthesias GBS variant.