Research by the RIVM shows that this unusual summer peak may be due to the fact that the Dutch population had fewer antibodies against the RS virus. Adults in particular seem to be the first to be infected again after the lifting of most corona measures.
Corona measures
Research in France and the United Kingdom also showed that more people became ill from the RS virus. Possibly because people came into less contact with the virus due to the corona measures. But how did immunity against the RS virus decrease due to the corona measures, and could that explain the summer peak? This has been investigated with blood samples from the PIENTER corona study.
PIENTER corona research
The PIENTER corona study has been looking at immunity against the SARS-CoV-2 virus since 2020. To this end, this RIVM study measures the antibodies of the Dutch population. The blood samples of 558 participants in this study were further examined for antibodies against the RS virus. These participants were randomly selected and between the ages of 1 and 89.
Fusion protein
The researchers looked for the presence of IgG antibodies against the fusion protein of the RS virus. These antibodies help render the RS virus harmless. The researchers compared blood samples from 558 participants taken at three different times in:
* June 2020 – a few months after the introduction of the corona measures.
* February 2021 – approximately 1 year after the last normal RS virus season.
* June 2021 – a few weeks after the lifting of the corona measures and the start of the increase in hospital admissions of patients with RS virus.
The comparison of the blood samples showed how immunity against the RS virus changed during the corona pandemic.
Between the 1st and 3rd measurement point, the IgG antibodies against the Fusion protein decreased significantly for almost all age groups. Only in the group between 31 and 40 years was the decrease not significant. People aged 71 and older had the most IgG antibodies. But in 9 of the 558 (1.6 percent) of the participants, IgG antibodies rose, probably due to exposure to the RS virus. These people were all over the age of 30.
Adults
The increase in the small group of participants over the age of 30 is striking. This could mean that adults were the first to become infected with the RS virus again when the corona measures were released in June 2021. Adults have been in contact with the RS virus more often than young children. As a result, they usually do not develop serious complaints and do not end up in hospital. We have found indications that the virus has circulated more in the Netherlands after the measures were lifted. The decreased immunity may have caused the striking summer peak.
It is clear that monitoring antibodies helps to understand why we saw a different summer peak in 2021 and who was the first to become infected again. The research continues to substantiate these preliminary results with additional time points and new blood samples. The researchers are therefore looking at which people are the first to become infected with the RS virus again.
By: National Education Guide