Cross-reactive coronavirus immunity | Professor Mala Maini
This theme investigates whether previous exposure to other coronaviruses, such as the four seasonal coronaviruses that are currently circulating in the UK, might influence how people’s immune systems respond to SARS-CoV-2. Researchers are investigating whether this could alter disease severity, perhaps offering some protection against SARS-CoV-2, as well as how the immune system responds when the virus mutates in places that help T cells recognise it.
Theme 4 Lead, Professor Mala Maini, and the Sub-theme Lead, Dr Thushan De Silva, have answered some common questions about our understanding of SARS-CoV-2 and the cross-reactive immunity they are investigating. These questions will be updated and added to over time as our understanding develops and priorities for research change.
Does having had a cold recently protect me from COVID-19? Could I have had a different strain of coronavirus (i.e. a different seasonal coronavirus) before that makes me immune to this one?
"SARS-CoV-2, the virus that causes COVID-19, comes from the coronavirus family of viruses so is closely related to the seasonal coronaviruses that cause the common cold (called OC43, HKU1, 229E, NL63). We all get these common colds from time to time and make immune responses to them (antibodies and T cells) which are usually quite short-lived. There is some evidence accumulating that some of our immune responses triggered by a recent common cold may be able to recognise similar portions of the SARS-CoV-2 virus – called immune ‘cross-reactivity’. This cross-reactivity is unlikely to make us immune to catching COVID-19 but it might change the way we mount an immune response to it. For example, it might partly explain why children (who get colds more frequently than adults) have milder COVID-19. Studies funded by UK-CIC are looking into this. (Cross-reactivity also means that tests showing T cells responding to COVID-19 need to be carefully distinguished from cross-reactive responses that may already have been present before the pandemic)."
If I have the flu and then catch COVID-19, am I likely to become more unwell?
"Having any two infections in quick succession can make you feel worse, particularly if both affect your lungs. However, there is no specific evidence that having flu will make you more ill if you then get COVID-19. In addition, it is not thought that the flu vaccine will alter COVID-19 infection or vaccination, although it is advised to leave at least a week between receiving these two vaccines."
Can any of the mutated forms of COVID-19 (i.e. a variant) escape the immune response?
"Viruses commonly develop mutations over time, although this has happened less for the SARS-CoV-2 virus that causes COVID-19 than for some other viruses like flu. Mutations are tiny changes in the virus’s genetic code. In principle, some variants that have been detected may be able to evade recognition by very specific antibodies. There is currently no evidence that a broad antibody response, such as one elicited by the currently approved COVID-19 vaccines, would be affected by these variants. Detailed studies are ongoing, and scientists are constantly checking any new mutations as they arise to ensure that immune responses induced by current vaccines will still be effective."
This page was last updated on: 15/01/2021