Did Britain get its initial Covid vaccine strategy WRONG? Mixing and matching first and second doses offer better immunity, study suggests

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  • Mixing and mixing COVID jabs triggers a strong antibody and T-cell response
  • Findings support flexible approach to rollout especially in low-income countries
  • In the UK, people received two doses of either Pfizer, AstraZeneca or Moderna

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Mixing and mixing the first and second Kovid vaccines may work better, according to a study that questions Britain’s original jabbing strategy.

All 46 million fully inoculated adults have so far received the same vaccine made by AstraZeneca, Pfizer or Moderna. But new research shows that giving a different jab for the second dose makes the immune response even stronger.

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After the first dose of AstraZeneca, Moderna or Novavax offered higher levels of antibodies and T-cells than either of the two Oxford-made injections. And those who had Pfizer had a stronger immune response than people who had two Pfizer jabs.

However, according to the results published in the Lancet, Novavax responded less strongly after Pfizer.

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Researchers from Oxford University analyzed six different combinations. They didn’t measure the vaccine’s effectiveness in the real world, but looked at levels of antibodies and T cells in laboratory tests — key indicators of immunity.

Principal investigator Professor Matthew Snipe said the findings suggest that there is ‘a great deal of flexibility’ around which vaccines are used and that people are not ‘locked in’ from taking the same second dose.

It comes with UK, which is facing enormous pressure to achieve a successful booster drive to protect against an expected omicron wave, in which immunity is reduced by two doses after several months. Experts agree that the top-up jabs will have a huge impact on the impending revival.

Ministers have already extended the rollout of the third dose to all over 18 and halved the waiting time between the second and third jabs to three months.

So far 20.5 million have received an additional dose of Pfizer or Moderna, or AstraZeneca if they can’t have mRNA vaccines, even if they have a jab for the first two doses.

Additional vaccine sites, volunteers and the military are being brought in to help with the rollout and health chiefs are easing the workload of NHS staff so they can help.

Professor Snape said there is as yet ‘no indication’ that Omicron causes more severe disease than previous variants, but if scientists confirm that it is indeed more contagious, it may increase the risk of people catching the virus. Large numbers will lead to more hospitalizations.

The graph shows the different combinations of the first and second doses and the antibody (left) and T cell response they produced (right). People who had Pfizer then Moderna had a stronger immune response than people who had two Pfizer jabs. However, Novavax reacted less strongly after Pfizer.

Overall, Pfizer (pictured) then Modern gave the best antibody levels, while AstraZeneca then Modern triggered the most T cells

Overall, Pfizer Modern (pictured) gave the best antibody levels, while AstraZeneca Modern triggered the most T cells

Overall, Pfizer (left) then Modern (right) gave the best antibody levels, while AstraZeneca Modern triggered the most T cells

The chart above shows the number of vaccine doses ordered by the UK, and which orders have been donated or cancelled.  This includes the latest orders for 54 million more Pfizer Doses and 60 million Modern Doses

The chart above shows the number of vaccine doses ordered by the UK, and which orders have been donated or cancelled. This includes the latest orders for 54 million more Pfizer Doses and 60 million Modern Doses

Omicron wave could put as much pressure on hospitals as last winter, albeit a mild one

Scientists have warned that the oncoming omicron wave could be as bad or worse for the NHS than the second coronavirus peak last winter, even if the super-mutant variant is weaker than its predecessors.

Real-world data suggests that the highly evolved version is three and a half times more likely to infect people than Delta because of a combination of its vaccine resistance, increased infectivity, and avoidance of antibodies.

Dr Simon Clark, a microbiologist at the University of Reading, said it was ‘entirely possible’ that Omicron could trigger a wave of hospital admissions to peak in January 2021 – even if it is milder than Delta’s.

He told MailOnline: ‘It is not uncommon for a more infectious but less disease-causing pathogen to cause a bigger problem than a virus that is less lethal. If it infects a very large number, but only a small percentage is hospitalised, we may still end up with a lot of people in the hospital.’

There are only 246 official Omicron cases confirmed in the UK so far, but there are likely to be more than a thousand already, according to Professor Paul Hunter, an epidemiologist at the University of East Anglia.

Professor Hunter said he expects it to become the dominant version ‘within the next weeks or a month’, based on how fast it is moving up the delta in the South African epicenter. He claimed that timeline means no more restrictions are needed over Christmas, but it doesn’t rule out the need for more restrictions at some point in the new year.

But Boris Johnson today refused to rule out tougher Covid restrictions into the festive period, insisting only that Christmas will be ‘better’ than last year. He is due to review the existing measures in two weeks’ time. Mr Johnson said on a visit to Merseyside: ‘We are still waiting to see how dangerous it really is, what kind of impact it has in terms of deaths and hospitalisations.’

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In the UK, people received two doses of either Pfizer, AstraZeneca or Moderna and only got the first and second jabs if they were participating in the trial.

Ministers last week ordered 54 million Pfizer and 60 million Moderna jabs to ‘future proof’ the vaccination plan.

The new study is one of six commissioned this year at the request of the UK government’s Vaccine Taskforce, which compared different booster jabs and whether COVID injections and flu shots can be given at the same time.

The most recent trial enrolled 1,072 participants who were given either Pfizer or AstraZeneca for their first COVID jab between January and March.

For their second dose about nine weeks later, participants were given either the same vaccine, Moderna or Novavax.

Novavax is not yet approved in the UK, but the data on the jab – which was…

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