SINGAPORE: An infectious disease expert in Singapore has raised concerns over findings that COVID-19 may lead to long-term cognitive impairment, including a decrease in IQ, especially in high-risk groups.
Reinfection, the expert told 8World, could exacerbate these cognitive declines.
He emphasized the importance of high-risk individuals receiving updated COVID-19 vaccines to mitigate the potential cognitive impacts of the virus.
The expert’s comments follow a series of studies from the United Kingdom that have uncovered significant cognitive declines in patients who have recovered from COVID-19.
One study indicated that the average IQ of patients dropped by approximately three points after recovery, with those who required intensive care experiencing a nine-point decline.
Additional findings from research conducted over two to three years post-infection suggest that cognitive decline in some patients can be as high as ten IQ points.
A study published in February by Imperial College London in the New England Journal of Medicine showed that, on average, COVID-19 patients who had recovered exhibited mild cognitive impairments, equivalent to a three-point IQ reduction.
This impairment was noted to persist for up to a year or longer compared to individuals who had never contracted the virus.
Patients whose COVID-19 symptoms had not resolved demonstrated an even more significant decline, equating to an IQ loss of six points, with intensive care patients showing an equivalent drop of nine points.
Researchers associated with this study explained that those with lingering symptoms exhibited more severe cognitive issues, impacting memory, reasoning, and executive functions.
Interestingly, patients infected with the early B.1.1.7 strain experienced greater cognitive deficits than those infected later, such as during the Omicron wave, suggesting that the connection between COVID-19 and cognitive decline may have weakened over the pandemic.
In another recent study published in The Lancet in September, teams from the University of Oxford and the University of Leicester found similar results, reporting an average IQ reduction of ten points in individuals two to three years after infection.
Notably, vaccinated individuals who had received two or more COVID-19 vaccine doses demonstrated better cognitive performance than unvaccinated counterparts.
Singapore’s Ministry of Health introduced updated Pfizer-BioNTech and Moderna/Spikevax vaccines last week to target the new JN.1 COVID-19 variant.
The ministry has recommended that people aged 60 and above, vulnerable individuals aged six months and older, and nursing home residents receive these updated vaccines.
Health authorities have also advised medical staff and those working closely with high-risk patients to consider vaccination, with eligibility for a booster dose starting five months after a previous shot.