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Is it just us, or does it seem like everyone you know has come down with COVID? Over the last few days, photos of positive tests and stories from self-isolation have flooded social media timelines, while others desperately try to track down the nearest booster jab.And, despite “Plan B” restrictions now being introduced in England, COVID-19 cases are still on the rise across the UK, with 59,610 new cases recorded on Tuesday. But should we really be worried about another lockdown? And if not will we need to keep getting boosted every time a new variant rears its ugly head?We spoke to Mark Jit, the professor of vaccine epidemiology at London School of Hygiene and Tropical Medicine, to find out why it feels like coronavirus is cutting a swathe through your friendship group ATM and whether he thinks “Plan B” will be enough to tackle Omicron. VICE: Why are so many young people getting COVID-19 at the moment?
Professor Mark Jit: Children and young people were more likely to get COVID during the Delta wave we had in autumn because they were less likely to be fully vaccinated than older people, so they were less protected. It is too early to tell with Omicron, but we do know that older people have the highest levels of vaccine coverage in the UK, and have also been prioritised for the booster vaccine. Hopefully, they will also be best protected against infection, since they are at highest risk of severe disease. However, booster doses in younger people will also be important to reduce transmission.How does the COVID-19 booster vaccine work?
The booster works in exactly the same way as the first two doses. It gives our immune systems another opportunity to learn to recognise and protect us against the virus that causes COVID-19. This causes our immune system to produce much higher levels of antibodies that can neutralise the Omicron variant – as well as other variants – of the coronavirus. However, for a more detailed explanation, you'll have to ask an immunologist – there is a lot more to the way our immune system works than this!How long does it take the COVID-19 booster vaccine to work? Could I go to a club right after getting my booster?
The big trial on boosters in the UK is the COV-BOOST trial which looked at a large range of vaccines given as a booster after either the Pfizer or AstraZeneca vaccine as the first two doses. They measured various markers of immune system activation, such as a class of antibodies called IgG and the activity of T-cells, at seven, 14 and 28 days after receiving the booster dose. They found increased levels after seven days, but for some primary series and booster combinations, the levels continued to increase at 28 days. If I were to give an overall conclusion, I would say that the booster is very likely to give additional protection after seven days, but it is possible that the full effect takes a little more time for some vaccines.How long does immunity from the booster last?
We don't know how long boosters will last since people only started getting them a few months ago. However, people who got the first two doses of the vaccines we use in the UK still had pretty good protection against other non-Omicron strains of the coronavirus six months later, although we were starting to see some signs of waning of protection by this time. For Omicron, however, without the booster people who were vaccinated six months ago do not seem to have much protection.Will we keep having to get boosters every year to protect us from new variants?
I certainly hope not, but at this point, it's impossible to predict how the virus may mutate in the future. In the long run, getting as many people vaccinated around the world will reduce virus circulation and that should reduce the opportunities that the virus has to mutate. New variants can arise anywhere in the world, and even the best travel restrictions will not stop them from eventually arriving in the UK and spreading. So, the only way to slow or stop the emergence of new variants is to work with the rest of the world to control transmission globally – we are really all in this together.Do you think another lockdown will be necessary to tackle the Omicron variant?
This is a decision for the government, who have to take into account many different factors besides health, such as the economy and the effect on people's day-to-day lives. Purely from the point of view of COVID-19 cases, we found in our modelling that with Plan B in place but without additional control measures, we are likely to see a wave of hospital admissions due to the Omicron variant in the coming months. Depending on the assumptions we make about this variant, the peak of this wave may range from being a bit lower than the wave we saw last winter caused by the Alpha variant, to being several times higher than that peak in the worst-case scenario if no further control measures are in place.@darceyedkins
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Professor Mark Jit: Children and young people were more likely to get COVID during the Delta wave we had in autumn because they were less likely to be fully vaccinated than older people, so they were less protected. It is too early to tell with Omicron, but we do know that older people have the highest levels of vaccine coverage in the UK, and have also been prioritised for the booster vaccine. Hopefully, they will also be best protected against infection, since they are at highest risk of severe disease. However, booster doses in younger people will also be important to reduce transmission.How does the COVID-19 booster vaccine work?
The booster works in exactly the same way as the first two doses. It gives our immune systems another opportunity to learn to recognise and protect us against the virus that causes COVID-19. This causes our immune system to produce much higher levels of antibodies that can neutralise the Omicron variant – as well as other variants – of the coronavirus. However, for a more detailed explanation, you'll have to ask an immunologist – there is a lot more to the way our immune system works than this!
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The big trial on boosters in the UK is the COV-BOOST trial which looked at a large range of vaccines given as a booster after either the Pfizer or AstraZeneca vaccine as the first two doses. They measured various markers of immune system activation, such as a class of antibodies called IgG and the activity of T-cells, at seven, 14 and 28 days after receiving the booster dose. They found increased levels after seven days, but for some primary series and booster combinations, the levels continued to increase at 28 days. If I were to give an overall conclusion, I would say that the booster is very likely to give additional protection after seven days, but it is possible that the full effect takes a little more time for some vaccines.How long does immunity from the booster last?
We don't know how long boosters will last since people only started getting them a few months ago. However, people who got the first two doses of the vaccines we use in the UK still had pretty good protection against other non-Omicron strains of the coronavirus six months later, although we were starting to see some signs of waning of protection by this time. For Omicron, however, without the booster people who were vaccinated six months ago do not seem to have much protection.Will we keep having to get boosters every year to protect us from new variants?
I certainly hope not, but at this point, it's impossible to predict how the virus may mutate in the future. In the long run, getting as many people vaccinated around the world will reduce virus circulation and that should reduce the opportunities that the virus has to mutate. New variants can arise anywhere in the world, and even the best travel restrictions will not stop them from eventually arriving in the UK and spreading. So, the only way to slow or stop the emergence of new variants is to work with the rest of the world to control transmission globally – we are really all in this together.Do you think another lockdown will be necessary to tackle the Omicron variant?
This is a decision for the government, who have to take into account many different factors besides health, such as the economy and the effect on people's day-to-day lives. Purely from the point of view of COVID-19 cases, we found in our modelling that with Plan B in place but without additional control measures, we are likely to see a wave of hospital admissions due to the Omicron variant in the coming months. Depending on the assumptions we make about this variant, the peak of this wave may range from being a bit lower than the wave we saw last winter caused by the Alpha variant, to being several times higher than that peak in the worst-case scenario if no further control measures are in place.@darceyedkins