Postvaccination breakthrough SARS-CoV-2 infections among adults in Malaysia and attitudes towards future vaccination

Objective:To determine the frequency and severity of the breakthrough infections and the associated factors in Malaysia.Methods:This cross-sectional study was conducted among the adult general population in Malaysia who completed at least one dose of vaccination.The validated online questionnaires were used for data collection between December 2022 to February 2023.The participants were recruited by a convenient sampling method.The data were analysed by descriptive statistics,and logistic regression by using SPSS(Version 27).Qualitative data from open-ended questions were analysed as thematic analysis by using RQDA software.Results:A total of 524 participants'data were analyzed and 77.5%of them completed three doses of COVID-19 vaccination.Breakthrough infections after vaccination were reported in 57.3%of the participants.Age group of 18 and 30 years(aOR 2.32,95%CI 1.01-5.32)and other ethnicities(aOR 2.00,95%CI 1.02-3.93)significantly associated with the occurrence of breakthrough infections.A total of 35.5%of the participants were not willing to take another booster dose in the future because of their attitudes towards fear of long-term side effects,lack of trust to the vaccine,less susceptibility to severe infection,belief in natural immunity,and myths.Conclusions:Future public health policies and interventions should be focused on disseminating the information about safety of booster doses of vaccine,management and re-assurance of side effects,and targeted vaccination to the working(younger age group)and ethnic minorities.

Effectiveness of intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine: An in silico pharmacological model

Objective:To explore the efficacy of intermittent preventive treatment in pregnancy(IPTp)with sulfadoxine and pyrimethamine(SP)against sensitive parasites.Methods:A pharmacological model was used to investigate the effectiveness of the previous recommended at least two-dose regimen,currently recommended three-dose regimen and 4,6,8-weekly regimens with specific focus on the impact of various nonadherence patterns in multiple transmission settings.Results:The effectiveness of the recommended three-dose regimen is high in all the transmission intensities,i.e.>99%,98%and 92%in low,moderate and high transmission intensities respectively.The simulated 4 and 6 weekly IPTp-SP regimens were able to prevent new infections with sensitive parasites in almost all women(>99%)regardless of transmission intensity.However,8 weekly interval dose schedules were found to have 71%and 86%protective efficacies in high and moderate transmission areas,respectively.It highlights that patients are particularly vulnerable to acquiring new infections if IPTp-SP doses are missed.Conclusions:The pharmacological model predicts that full adherence to the currently recommended three-dose regimen should provide almost complete protection from malaria infection in moderate and high transmission regions.However,it also highlights that patients are particularly vulnerable to acquiring new infections if IPTp doses are spaced too widely or if doses are missed.Adherence to the recommended IPTp-SP schedules is recommended.