A vancomycin dosing guideline was published in 2020 specifically for the management of serious methicillin-resistant Staphylococcus aureus (MRSA) infection with a recommended target area under the concentration-time curve (AUC)/minimum inhibitory capacity (MIC) of 400 to 600 mcg*h/mL using the Bayesian model. Aside from MRSA, there is limited data available regarding the AUC target goal for other antibiotic-resistant organisms which has excluded recommended AUC goals for other infections. As a result, the 2022 vancomycin-focused guideline from the Japanese Society of Therapeutic Drug Monitoring (JSTDM) recommends altering the dosing regimen based on treatment response when treating non-MRSA infections, possibly yielding AUC/MIC <400 mcg*h/mL. For empiric therapy prior to determining the MIC, a target AUC of 400 mcg*h/mL or greater is recommended (presuming MIC is 1 mcg/mL). AUC should not exceed 600 mcg*h/mL due to the increased risk of acute kidney injury (AKI). [1-2]
A Q&A briefing on the Sanford Guide website regarding the 2020 guidelines addresses similar concerns regarding the AUC/MIC 400 to 600 limit. Due to limited data, the AUC target range only applies to serious MRSA infections. Other serious and nonserious infections are excluded from the recommendations. 
A 2021 meta-analysis analyzed the efficacy and safety of vancomycin AUC cutoff in five clinical trials, although the primary infection was MRSA-associated bacteremia or septic shock. No other infection was evaluated. Target AUC/MIC breakpoints varied between studies ranging from 393 to 451. The meta-analysis authors utilized an AUC/MIC cutoff of 400 (400 ± 15%, 392.7 to 451) to indicate success which found a higher AUC/MIC ratio was correlated with lower rates of treatment failure (odds ratio [OR] 0.28; 95% CI 0.18 to 0.45; p<0.0001). In contrast, an AUC/MIC cutoff of 600 was associated with higher rates of acute kidney injury. 
A 2020 review reported data on vancomycin AUC monitoring specifically within the pediatric population, although evidence is limited. Retrospective studies did not reveal a relationship between the vancomycin AUC24 ≥ 400 mg*h/L in patients with MRSA bacteremia. But given the lack of prospective pediatric data, the authors suggest extending the guideline recommendation of 400 to 600 AUC/MIC to the pediatric population.