There is a lack of clear evidence that someone who has contracted Covid-19 will develop the long term anti-bodies to protect them from further infection, according to a new analysis of research by Ireland's health service watchdog.
The Health Information and Quality Authority (HIQA) has published new summaries of academic research and evidence to support the National Public Health Emergency Team’s (NPHET’s) response to COVID-19.
HIQA said it also found that there remains a lack of clear evidence as to whether long-term immunity is possible from SARS-CoV-2 - the virus that causes Covid-19.
HIQA’s Deputy CEO and Director of Health Technology Assessment is Dr Máirín Ryan.
“Studies have shown that antibodies against SARS-CoV-2 develop soon after infection. Immunoglobulin G antibodies (that contribute to long-term immunity) have been detected for at least two months after infection. However, as SARS-CoV-2 is a new virus, there is no long term evidence of immunity. Continued monitoring is needed to assess the adequacy and duration of the immune response for COVID-19.
"Evidence for other types of serious coronavirus infections, such as SARS-CoV-1, shows that the antibody response is maintained for one-to-two years after initial infection and decreases thereafter. As yet, it is also not certain if antibodies are transferred from mother to the child in the womb via the placenta.”
“It is not yet possible to determine if reinfection is possible following recovery from Covid-19. While some individuals have tested positive after recovery, this is likely due to virus re-detection where there is intermittent shedding of the virus rather than reinfection with a second virus. To date, there is no evidence that these individuals are infectious to others," she said.
The evidence summaries were developed by HIQA following requests from NPHET’s Clinical Expert Advisory Group and are informing the national response to the pandemic.
Dr Ryan said HIQA develops evidence summaries following a thorough search of bibliographic databases, screening of identified studies to match relevant clinical questions, data extraction and quality appraisal of included studies.
"This robust process ensures that public health decisions are informed by the best available evidence and information from across the world,” she said.
Read the evidence summaries at https://bit.ly/2R4eL6f.