Vaccines may not be able to ward off long Covid risk, finds study

Even vaccinated people with mild breakthrough Covid-19 infections can experience debilitating, lingering symptoms that affect the heart, brain, lungs and other parts of the body, according to new research.

Previous studies claimed that vaccination, which remains critically important in the fight against Covid-19, wards off the long Covid risk. Yet the study found long Covid risks to be higher among people who are unvaccinated.

The study, published in the journal Nature Medicine, showed that long Covid risks were 17 per cent higher among vaccinated immunocompromised people with breakthrough infections compared with previously healthy, vaccinated people who experienced breakthrough infections.

But, compared with unvaccinated patients infected with the virus, vaccination were found to reduce the risk of death by 34 per cent and the risk of getting long Covid by 15 per cent, said researchers at Washington University in St. Louis.

The findings also showed vaccines to be most effective in preventing some of the most worrisome manifestations of long Covid - lung and blood-clotting disorders - which declined about 49 per cent and 56 per cent, respectively, among those who were vaccinated.

"Vaccinations reduce the risk of hospitalisation and dying from Covid-19. But vaccines seem to only provide modest protection against long Covid. People recovering from breakthrough Covid-19 infection should continue to monitor their health and see a health-care provider if lingering symptoms make it difficult to carry out daily activities," said first author Ziyad Al-Aly, a clinical epidemiologist at the Washington University.

Al-Aly stressed the need to "urgently develop and deploy additional layers of protection that could be sustainably implemented to reduce the risk of long Covid".

Such protective layers could include nasal vaccines that are more convenient or potent than the current shots, or other types of vaccines or drugs aimed at minimising the risks of long Covid.

For the study, researchers examined data of 113,474 unvaccinated Covid-19 patients and 33,940 vaccinated patients who had experienced Covid-19 breakthrough infections, all from January 1 through October 31, 2021.

A further analysis of 3,667 vaccinated patients who were hospitalised with breakthrough Covid-19 infections showed that they had a 27 per cent higher risk of long Covid in the first 30 days after diagnosis compared with 14,337 people who were hospitalised with seasonal influenza.

--IANS

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