A new study from the University of Oxford has found that the risk of developing Long-Covid symptoms is significantly lower in individuals who have received two doses of the Covid-19 vaccine compared to those who are unvaccinated. While previous research has shown that Covid-19 vaccinations reduce the rate of SARS-CoV-2 infections, it was unclear whether the risk of Long-Covid was lower in vaccinated individuals who still contracted the virus. The study, published on the preprint server medRxiv, found that the likelihood of Long-Covid symptoms in vaccinated individuals after a SARS-CoV-2 infection was 41% lower.
The researchers analyzed data from 3,090 participants who were double vaccinated and tested positive for SARS-CoV-2 between April 2020 and November 2021. The majority of participants (74%) received the Oxford/AstraZeneca vaccine, while the rest received Pfizer/Biontech (25.5%) or Moderna (0.5%). The study also included a control group of unvaccinated individuals who were matched 1:1 with the vaccinated group. The results showed that Long-Covid symptoms occurred in 9.5% of vaccinated participants, compared to 14.6% of unvaccinated participants.
The study also found that the type of vaccine (vector or mRNA) did not affect the risk of developing Long-Covid symptoms. However, it is important to note that the study was conducted during a period when the Delta variant was dominant in the UK, and the unvaccinated participants were infected mostly before this time. Therefore, it is possible that the differences in the likelihood of Long-Covid symptoms between the two groups may be due to exposure to different Covid-19 variants.
Overall, the study provides further evidence that Covid-19 vaccinations not only reduce the risk of infection but also significantly lower the risk of Long-Covid symptoms after a breakthrough infection. These findings highlight the importance of vaccination in preventing both short-term and long-term health consequences of Covid-19.
