Immune cell activation is a feature of COVID-19, that leads to cytokine storm which causes neurotoxicity, neuroinflammation, and neurodegeneration, related to psychiatric symptoms due to the depletion of neurotransmitters, dopamine, serotonin, norepinephrine, GABA, and glutamate which play a major role in adult neurogenesis. ACE2 receptors are expressed in the hippocampus and decreased neurogenesis in this region is a major factor behind the neuropsychiatric disorders. SARS-CoV-2 can affect the brain indirectly through neuroinflammation and altered neurochemical signaling and even mild COVID-19 infections can lead to sustained microglial activation, which disrupts neural networks and impairs cognitive function. The long COVID-19 may be associated with cognitive dysfunction in those who recovered and immunological response may affect synaptic pruning and reduced anterior cingulate cortex volume at one year after COVID-19. Post-acute sequelae of SARS-CoV-2 infection or PASC, commonly known as Long COVID is a significant public health concern and "brain fog" is one of the most debilitating cognitive impairments, affecting memory, concentration, and executive function occurring in 88% of cases. Brain fog may be linked to persistent changes in neurotransmitter levels, particularly involving dopamine and serotonin which play an essential role in cognition, attention, and emotional regulation. Elevated levels of pro-inflammatory cytokines, the chemokine CCL11, is linked to cognitive impairments in patients with persistent symptoms. Neuroprotective agents that support neuronal health, such as antioxidants and mitochondrial enhancers and noninvasive brain stimulation techniques such as transcranial magnetic and direct current enhance cortical excitability are investigated in cognitive recovery. Evaluation of the currently predominant VUM (a Variant Under Monitoring), LP.8.1, and the most recently designated NB.1.8.1, is increasing as 10.7% of global sequences reported recently due to minor mutations in spike protein. In May 2025, TAG-CO-VAC (Technical Advisory Group on COVID-19 Vaccine) advised that the monovalent vaccines targeting against JN.1 or KP.2 lineages are highly appropriate.