SARS-CoV-2 S-RBD IgG & Neutralizing antibodies among different categories of health care workers post third dose BNT162b2 mRNA COVID-19 vaccine.

Neutralizing antibodies (NTAb) play a significant role in preventing and protecting against SARS-CoV-2 virus infection. Identifying NTAb is undoubtedly imperative in understanding the immunity toward COVID-19 better. However, it is interesting to note that the production of NTAb varies among individuals, especially among healthcare workers (HCWs), as they are exposed to the virus daily. Hence, we would like to investigate factors affecting the production of S-RBD IgG and NTAb among different categories of HCWs, particularly after receiving the third dose of the BNT162b2 mRNA COVID-19 Vaccine. A total of 361 HCWs from our hospital were prospectively enrolled and had their S-RBD IgG and NTAb titers measured. They were studied in relation to the degree of exposure to COVID-19, breakthrough infections, gender, age, race, household income, housing type, household number, and education levels. HCWs with the highest risk of exposure to COVID-19, breakthrough infections, and male gender displayed the highest median titers of both S-RBD IgG and NTAb, and the differences were statistically significant (p < .05). Age, race, household income, housing type, household number, and education levels were revealed to be insignificant. We concluded that the degree of exposure to COVID-19, breakthrough infections, and male gender are significant factors in NTAb production among HCWs.

Lime juice as a dietary alternative to mist potassium citrate for urine alkalinisation: A prospective, cross-over clinical trial.

Introduction: Urinary citrate is a potent inhibitor of urinary crystallization that is freely filtered in the proximal tubule of the kidney. We aimed to investigate the effect of citrate supplementation with fresh lime juice on the urinary pH and calcium excretion level among healthy individuals compared with that of mist potassium citrate. Method: In this prospective, cross-over single-centre study, 50 healthy medical student volunteers were randomly allocated to two treatment arms. One arm was prescribed with potassium citrate, while the other arm received citrate supplementation with a home preparation of fresh lime juice. The urinary pH and calcium-to-creatinine ratio (uCa/uCr) were measured at baseline and after 7 days of treatment. This was followed by a washout period of 2 weeks, after which each participant crossed over to the other treatment arm, and the urinary measurements were repeated. Results: Potassium citrate significantly increased the urinary pH among all participants, while fresh lime juice did not. Both fresh lime juice and potassium citrate reduced the uCa/uCr, although this effect was not significant. Conclusion: Fresh lime juice is not as effective as potassium citrate in improving the urinary pH and calcium excretion level of healthy individuals. Therefore, it should be used as an adjunct rather than an alternative to potassium citrate.