Vaccines, variants, and the return to campus

The Joint Committee on Vaccination and Immunisation (JCVI) has recommended to the Westminster government that people under 30 or with particular risk factors should be offered other Covid-19 vaccines in preference to the University of Oxford/AstraZeneca injections.

What’s going on?

Their reason for this is that regulators in the UK and EU have reported a very slightly higher than normal incidence of a rare type of blood clot (linked to a low platelet count, which is unusual as platelets are the part of your blood that makes it clot) in those who have received the Oxford/AZ vaccine. The British Medicines and Healthcare products Regulatory Agency (MHRA) examined 79 reported cases, of which 19 were fatal.

As of 31 March there’s been 20.2m doses of the Oxford/AZ vaccine given in the UK. This puts the risk of this rare type of blood clot something in the region of 4 people in every million. This small incidence rate is all the more remarkable if you consider that the UK has prioritised elderly and other at-risk people in vaccination so far.

For nearly everyone, the risk of being hospitalised with Covid is currently far, far greater than the risk of being hospitalised with this rare blood clot. There have been no cases among people who have had the full course (two injections) of the Oxford/AZ vaccine. If you’ve already had half (one injection) of the vaccine the advice is that you should have the other half when offered it – unless you’ve already experienced this form of blood clot. If you are pregnant, trying to get pregnant, or you have any condition (or are on any other medication) with links to blood clots you should speak to a medical professional.

For the moment – under 30s will be offered other vaccinations (the Pfizer one or the Moderna one). Depending on where you live, most vaccinations are currently offered to over 40s or over 50s. Some under 30s – usually those at risk or with caring responsibilities – have been offered vaccines already, others no doubt will be in the coming weeks. The advice regarding the choice of vaccine for under 30s is not because the Oxford/AZ vaccine is unsafe – it is because the risk of complications from contracting Covid among healthy under 30s is of a similar magnitude to the risk of this side effect.

What’s the big picture?

A peep at the Wonkhe Covid data dashboards will tell you that there’s thankfully not much of the virus about in the UK right now, and the trend is downwards. Mass vaccination is clearly helping, as are the measures we are all taking to stop the spread of the virus. The path is not smooth – there will be small rises in cases as we remove some of these measures and more social mixing occurs. But things are looking hopeful.

Globally, the UK/Kent variant of the virus is causing a sharp rise of cases in Europe and the US – and there are other variants (notably in South Africa, Brazil, and Nigeria) of concern. New variants of the virus (versions of Covid-19 that have mutated to spread more easily in current conditions) are the biggest thing we are concerned about now – it is possible that not all vaccines will be effective against some variants.

Variants happen all the time when a virus infects someone and reproduces – occasionally a copy of the virus will be made that is different from others in a random way. Mostly these variations stop the virus working and immediately die out – very occasionally a random variation will give a copy of the virus an advantage over others: perhaps it would be better at copying itself, or better at evading the body’s defences, or better at being passed to other people.

The best way to avoid generating new variants is to keep case numbers as low as possible, by stopping people getting infected. Social distancing and other safety measures are one way of doing this, vaccines are another. If you have been vaccinated, the virus is unable to reproduce in a viable way in your body – though it is reckoned that you can still pass the virus to others. That’s why even if you have been fully vaccinated you still need to wear a mask, wash your hands, and observe social distancing rules. And it’s why regular testing (and a good track and trace system) is a better way to reopen society than “vaccine passports”.

People have been concerned about a possible slowdown in the vaccination programme due to the changes in the way we use the Oxford/AZ vaccine – though the government have told us that there will be no impact in vaccine rollout. There could be a risk if older people take the recent burst of publicity as a sign that this particular vaccine is unsafe  in general (you’re far more likely to die in a road accident, or for that matter from actual Covid-19) and refuse to be given it. That’s part of the reason I’m writing this article – for most people having the Oxford/AZ vaccine if you are offered it is a really good idea.

In UK higher education

A big chunk (though not all – half a million UK students at all levels of study are over 30) of students are under 30, and most will not have been vaccinated yet. You’ll recall that as things stand under 30s are less likely to suffer the nastier side effects of Covid-19. We saw back in October that students mixing in halls of residence are quite likely to catch the virus but are unlikely to spread it to the wider population or experience any serious health issues. There’s very little evidence of students catching or spreading the virus in other campus settings – but balance against that the amount of safeguards and restrictions in operation on campus.

Currently, university representative bodies are making the case for an earlier return to campus – students and staff appear to be less convinced. Depending on who you ask, it is reckoned that more than half of students are living at their term time address anyway. Summer term is not generally a period of intense academic activity, and for me at least the case for return is not a convincing one.

Remember the stuff above about variants? My big worry is that mixing loads of unvaccinated students would lead to new infections and possible new variants, and might increase the transmission of the variants we are already worried about. Thought this (most likely) won’t have a health impact on most students, we want to keep infections low across the UK and present less opportunity for the virus to reproduce. And then there’s long Covid, of course. We want to avoid that.

Viruses tend to be less active in the warmer summer months anyway, which is why people are starting to turn their minds to the fourth wave in autumn 2021. If we get the vaccination and social measures right, there won’t be enough of the virus around to spread far, there won’t be enough chances for it to reproduce and mutate, and it will feel more like flu season than what we’ve been through in the past year. If we get these things wrong, we could be in for another lockdown, more vaccinations, and more risk.

Clearly I’m not a virologist or epidemiologist. The above is based on my reading of current (8 April 2021) advice and guidance, and I’d strongly urge people to seek other sources (I recommend starting with the BMJ coverage which is free to read, comprehensible by non-specialists, and up to date)