CORONAVIRUS vaccines are being rolled out across the UK in order to protect people from the deadly illness.
But how long will immunity last after your jab and will antibodies protect you for long periods of time?
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So far across the UK over 22.2 million Brits have received a first dose of either the Pfizer/BioNTech jab or the Oxford/AstraZeneca offering – with over 1.1 million having now had a second dose.
Last week Health Secretary Matt Hancock revealed that a single dose of either the Oxford or Pfizer vaccine can slash hospitalisations from Covid in older people by 80 per cent.
He said that "a single shot of either the Oxford/AstraZeneca vaccine or of the Pfizer vaccine works against severe infection among the over-70s with a more than 80 per cent reduction in hospitalisations".
"In fact, the detailed data show that the protection that you get from catching Covid 35 days after a first jab is even slightly better for the Oxford jab than for Pfizer, albeit both results are clearly very strong", he said.
Experts have however stated that booster shots could be needed in order for people to continue to have protection from the virus – as immunity from jabs may not last forever.
Writing in The Conversation expert in biochemistry at Trinity College Dublin, Professor Luke O'Neill said there are several different variables when it comes to how long you will have immunity for after any vaccine – including the Covid jabs.
He explained that the type of pathogen (an organism that causes disease) infecting you, to how bad the initial disease is, to your overall health, and your age can all have an impact.
Prof O'Neill said that Covid sits somewhere between measles and the flu when it comes to how effective jabs and antibodies can be.
People develop antibodies when they have been exposed to a virus and this can protect them from catching a virus again and become ill from it.
Measles is a stable virus, it doesn't change much and produces a strong immune response and you only need one vaccine to be protected.
The flu however is ever changing and people need to be jabbed each year as it continues to evolve.
Prof O'Neill said: "We might expect immunity to last against Covid-19, but probably not as long as measles. And we’ll probably have to vaccinate against variants that emerge, as we do for flu."
This could mean that people get a year jab for Covid.
One of the good things about the Covid-19 virus he added, is that it is a repetitive virus.
He compared it to smallpox, which also has a highly repetitive surface and said that antibodies for this illness "last a lifetime".
This could mean that if you have already had Covid-19 then you have a higher level of protection than someone who has not caught the virus.
Prof O'Neill did however say that "it’s well worth giving a booster" due to the fact that new spike proteins develop which cover the surface of coronavirus.
IMMUNE RESPONSE
Prof O'Neill said that if antibodies don't work against new variants that evolve, the T-Cells could.
T-Cells are the part of the immune system that focus on foreign particles such as new viruses that try and enter the body.
Prof O'Neill said that how T-Cells react to Covid-19 could "mean that we won’t need boosters at all and that we might have long-term protection against multiple variants".
"And even if the immune response is lower against variants, we will probably still be protected from severe disease", he added.
He said that one important part of natural infection is how strong the initial immune response is.
"The common cold often only provokes a mild response in the upper airways. This is because a virus that limits itself to your nose isn’t much of a threat.
"It means that the immune response doesn’t really get going at all. It’s insufficient for memory B and T cells to emerge.
"If flu causes a big fight, which the immune troops never forget, the common cold is a mere skirmish that is soon forgotten", he said.
Prof O'Neill explained that a mild dose of Covid-19 could work in a similar way.
He explained: "If you’ve had a more pronounced disease, this might stand you in good stead and make you more resistant to reinfection.
"But if you only had mild disease, or if you stayed symptom free, you are at risk of reinfection."
VACCINE POWER
Vaccines he said, usually give a much stronger immune response than natural infection.
Prof O'Neill explained: "This is because natural immune responses lack the guile of the pathogen, many of which have elaborate ways to turn off the immune response.
"This is down to evolution."
He said that viruses that carry proteins that can limit immunity will be more likely to survive.
"This may be especially important with SARS-CoV-2, which carries several ways to limit immunity.
"Because the vaccines comprise either one part of the virus – such as the spike protein – or a whole inactivated virus, they don’t limit immunity, and so a robust immune response occurs."
He highlighted that the Moderna vaccine, which is currently being rolled out across the US has been shown to provoke a durable antibody response, where the natural infection is more variable.
He said that experts are "highly confident" that being infected with Covid-19 will offer you some protection but stated that with new variants emerging, "it is wise to prepare for booster shots with new vaccines for those who are vulnerable".
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