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Dr Colin

Answering all your Health and Immunity concerns

Dr Colin Hamilton-Davies, our health and immunity specialist, is here to answer your questions on all aspects of immunity and health.

Dr Colin Hamilton-Davies

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Q: Will COVID-19 booster jabs really “strengthen the wall of protection”?

Over the last week, I have received several questions relating to the new COVID-19 booster jab programme set to begin this week. While some of these have asked about the details of the programme, others have expressed concern about the efficacy of booster jabs and whether they will really offer us the additional protection they claim.

So, in this week’s blog post, I have decided to address both strands of queries. I will begin by addressing some common concerns going through people’s minds – why are booster jabs needed, which vaccines are being used for the booster jab, and will they become a regular feature of life going forward? After this, I will turn to the more heated question of whether they will truly “strengthen the wall of defence” created by the vaccines, to borrow the recent words of Health Secretary Sajid Javid.

Although many voices have answered with a resounding “yes”, the answer, in fact, may be less certain than this. While studies have shown that the effects of COVID-19 vaccinations after the second dose start to wane in the period following three months, the booster jabs may only enhance our immunity against the virus by a relatively small amount, and may in fact only be needed by a small number of elderly and immunocompromised people. The possible scenario of giving booster jabs to groups who don’t actually need them has led some experts to claim that there are possible “moral implications” if this means depriving people in poorer countries of vaccinations that are in very short supply.

Javid’s claim that booster jabs will “strengthen the wall of protection” may risk oversimplifying the situation. Nevertheless, the booster jab programme will still provide many people with the additional protection they need.

What is the booster jab programme?

The booster jab programme is a government initiative aimed at addressing the waning immunity provided by the original two jabs, with the goal of preventing hospitals from being overwhelmed with new patients over the coming autumn and winter months, when a resurgence in flu and other respiratory diseases, including COVID-19, is expected.

According to data recently published by Public Health England, the levels of protection provided by the original two jabs against severe symptoms and death from COVID-19 wanes in the period following three months from the time of the second dose.

While the rate of waning has been found to be most severe among the elderly and immunocompromised, the lowering of protection is still relatively low – for example a drop from 90% to 80% protection. Nevertheless, translated into a population basis, this could still result in significant numbers of people being hospitalised over the coming months.

Who will receive the booster jabs?

The programme is set to begin unrolling this week, with booster jabs being offered first to elderly care-home residents, and thereafter to adults aged 50 and over in age group cohorts. The jabs will also be offered to frontline health and social care workers and young adults with underlying health conditions. People living with or caring for vulnerable adults will also be offered the booster jab. No one will receive a booster jab less than six months following their second dose of the vaccine.

At present, there are no plans to offer people under the age of 50 without underlying health conditions the booster jab this year. However, Public Health England have stated that research will be undertaken to assess the possible benefits of providing it to this group. If the benefits are significant, then we may see a similar rollout for this group beginning sometime next year.

The mRNA vaccines manufactured by Pfizer and Moderna are currently being favoured for the booster jabs in the UK. This is because they have been shown to be slightly more effective at providing immunity and carry lower risks of the rare blood-clotting side-effects widely reported in the media, as compared to the Oxford/AstraZeneca vaccine.

In some rare cases, for example in the case of those for whom an mRNA vaccine is not advised for a specific medical reason, the Oxford/AstraZeneca jab may be used.

Will they become a regular feature of life?

At this early stage, scientists are hesitant to give any indication of the durability of the additional immune protection that booster jabs will provide. As such, it is difficult to predict whether booster jabs will become a regular feature of life going forward.

There is nevertheless hope that the more we boost, the longer our immunological memory will last prior to us needing another jab. The more we are exposed to the antigen part of the virus, the less frequently we will need to boost in the future. There will hopefully come a point when our bodies learn to live with COVID-19 as an endemic disease. In this scenario, we would only need to vaccinate against other variants, with preference being given to the most vulnerable in society.

Will booster jabs “strengthen the wall of protection”?

Chris Witty recently claimed that “the logic of boosters for the UK is clear and science-based”. According to this reasoning, there is clear evidence that the protection provided by the original two jabs wanes in the period following three months, and that booster jabs stand to raise this protection. It is therefore imperative on government to guard against the overwhelming of hospitals this autumn and winter.

Booster jabs will indeed offer much needed additional protection to the most vulnerable in society, especially over the coming months. However, as I have already suggested, talk of “strengthening the wall of protection” may risk oversimplifying the situation.

The third COVID-19 vaccine is in all likelihood only needed for a relatively small number of people comprising the elderly and immunocompromised, as numerous experts have stated. Professor Adam Finn, a member of the Joint Committee on Vaccination and Immunisation, has said it is still unclear whether the wall of protection for this group will need to be further extended.

There is need for additional evidence as to whether people who have received the original two jabs are at any serious risk of severe infection and whether their immunity against COVID-19 is still strong, says Finn. In the absence of such clear-cut evidence, we may risk giving the booster jab out to people who don’t need it.

In this scenario, there may be moral implications in the case that booster jab programmes end up depriving those in poorer countries around the world from vaccines that are globally in short supply.

This has led organisations such as WHO to oppose the rolling out of booster jab programmes. Other experts, such as Anthony Fauci, have taken a more balanced opinion, stating that it is possible to both address the global supply of vaccines and roll out booster programmes at the same time. How exactly we go about balancing global and domestic concerns, however, remains unclear.

Opinion is clearly divided on this issue, and talk of “strengthening the wall of protection” is far from clear-cut, as further evidence is needed. Nevertheless, we should be grateful for those who will begin receiving the boosted protection they need over the coming months.

Colin Hamilton-Davies

Dr Colin has over 30 years of experience working as an intensive care specialist.
He’s the Clinical Lead for the Acute Cardiac Critical Care Department at St Bartholomew’s Hospital, City of London, one of the largest critical care units in the UK. He is also Clinical Associate Professor at University College London, where he has been involved in research on the immune system for the past 25 years. Dr Colin is passionate about health & wellbeing and helping people proactively improve their immunity and health.

“Over the coming weeks, Dr Colin in collaboration with Thrive4Life, will be providing you with practical advice on various aspects of immunity and health.”

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    Dr Colin’s responses are intended for informational and educational purposes only and do not constitute medical advice. If you intend on making any change to your diet, lifestyle or exercise routine based on the information provided, make sure to consult your GP or medical professional first to discuss any health concerns. Neither Dr Colin nor Thrive4Life are liable for any issues associated with using or acting on the information on our blog.
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