My third COVID-19 infection: Why reinfection can be anything but mild

Vaccination and natural immunity have dramatically reduced the death toll from COVID-19, but catching COVID-19 for a third time is still no walk in the park, as Linda Geddes discovered last week.

  • 10 October 2022
  • 7 min read
  • by Linda Geddes
Woman wiping her nose with tissue laying on the couch. Photo by Andrea Piacquadio from Pexels
Woman wiping her nose with tissue laying on the couch. Photo by Andrea Piacquadio from Pexels
 

 

As the pandemic approaches its third anniversary, most people are well and truly bored with COVID-19. With so many of us having recovered from at least one COVID-19 infection, not to mention being vaccinated and/or boosted, it is seductive to believe that catching it again won’t matter.

I’ve been to pubs and parties, packed myself onto public transport without a facemask, and entertained various guests with ‘colds’. But having just experienced COVID for the third time, I am regretting letting my guard down.

This is particularly true in the Omicron era, where we’re encouraged to believe that COVID-19 is ‘nothing but a minor sniffle’ and we must ‘learn to live with the virus’. I too have been enjoying largely living life as if the pandemic never happened in recent weeks and months. I’ve been to pubs and parties, packed myself onto public transport without a facemask, and entertained various guests with ‘colds’. But having just experienced COVID for the third time, I am regretting letting my guard down.

I am not advocating a return to full or even partial lockdowns; I desperately want my kids to continue attending school, and I don’t think pubs or restaurants need to stop serving customers indoors either. But as evidence mounts that northern hemisphere countries could experience a new wave of COVID-19 infections as winter approaches, combined with the return of influenza and other everyday illnesses, the onus is on everyone to do what they can to keep themselves – and each other – healthy.

COVID-19 reinfection

This latest bout of COVID-19, was my third in less than three years. The first, in March 2020, was characterised by a persistent cough and chest pains; the second, in June 2021, by fatigue and loss of taste and smell (I still suffer from “parosmia”). Having recovered from these infections, and been vaccinated, and boosted – twice – I had assumed that were I to catch it again, any illness would be negligible.

Ever since the rise of Omicron, scientists have talked about its relative mildness – particularly in healthy people who have been vaccinated, like me. But my third experience of COVID-19 has been my worst yet.

Part of the problem, I think, is that the medical description of “mild illness” is at odds with the normal perception of “mild”, such as with mild weather or mild cheese. When doctors and scientists talk about “mild COVID-19”, what they mean is “not severe enough to cause breathing difficulties”.

This time, I experienced various “cold-like” symptoms – sore throat, sneezing, runny nose – but it was the feverishness and headaches that immobilised me in bed for three days, unable to cook, do anything for my kids, or work. Fortunately, I am gradually starting to feel better, but my experience of “mild COVID” was easily on par with flu – an illness I previously vowed never to catch again. The possibility of going through it all again next year, assuming that’s what ‘living with coronavirus’ means, is already filling me with dread.

Waning immunity

Whereas at the start of the pandemic, nobody had any immunity to SARS-CoV-2, nearly three years on, everyone’s immune systems are on a slightly different learning curve.

Unfortunately, current COVID-19 vaccines still only top-up people’s immune protection for a limited period before their antibody levels begin to drop. They will still be largely protected against severe disease and death, but waning antibodies increase individuals’ susceptibility to reinfection.

Although at the extreme end of the spectrum, reinfections tend to be less severe than people’s first brush with SARS-CoV-2, data from the UK’s Office for National Statistics have suggested that the proportion of people reporting symptoms during reinfection varies according to which variants they have been infected with before. When they were infected, relative to their last COVID-19 infection or vaccination, could also influence their symptom severity, because levels of protective antibodies gradually diminish over time.

Then there’s how much virus someone is exposed to. According to Ben Krishna, a postdoctoral researcher in immunology and virology at the University of Cambridge, UK, infection with a higher dose of virus (say, if someone with COVID-19 sneezes in your face) could enable higher levels of virus to gain a foothold in the body before the immune system manages to stamp them out, resulting in more severe symptoms.

Booster campaign

My last COVID-19 booster was in June, so I was surprised to have come down with it again so soon. My experience shows that boosters do not offer total protection from the disease even though they are very effective in preventing severe disease and death. COVID-19 vaccines have had a massive impact on people’s risk of being hospitalised with or dying from the disease, and are the reason many countries have largely been able to return to normal life, without hospitals being overwhelmed. 

Unfortunately, current COVID-19 vaccines still only top-up people’s immune protection for a limited period before their antibody levels begin to drop. They will still be largely protected against severe disease and death, but waning antibodies increase individuals’ susceptibility to reinfection.

Unlike the COVID-19 waves we experienced during 2020 and 2021, where a single variant, such as Delta, rapidly outcompeted all others and spread across the world, virologists are currently tracking the growth of multiple subvariants

The rationale for some countries launching COVID-19 booster campaigns in the coming weeks and months is to temporarily boost antibodies, reducing the risk of a sharp increase in severe cases, precisely when hospitals are likely to be grappling with a spike in influenza admissions. It is therefore important to take up the offer of a booster vaccine, if you are offered one, but it won’t make you invincible.

Viral evolution

Then there’s the issue of increasingly immune-resistant subvariants. Although the WHO hasn’t assigned any new Greek letters since Omicron, the subvariant that’s making me sick is likely very different to the one that infected my husband in early March, which was itself quite different to the original BA.1 version of Omicron that emerged in November 2021. The number of new, and potentially worrying Omicron subvariants in circulation right now, is unprecedented.

Unlike the COVID-19 waves we experienced during 2020 and 2021, where a single variant, such as Delta, rapidly outcompeted all others and spread across the world, virologists are currently tracking the growth of multiple subvariants, each carrying overlapping changes to the spike protein, which SARS-CoV-2 uses to grab onto, and infect human cells. Crucially, these mutations affect the ability of antibodies to recognise the virus and block it from infecting us.

If you are unfortunate enough to be reinfected, it is still likely that your infection will be mild. But mild doesn’t necessarily mean trivial. Not everyone has the benefit of sick pay, or a partner who can take over all childcare duties while their other half quarantines in bed.

Although vaccination and previous COVID infections have left us with other weapons against the virus, its ongoing evolution and individuals’ waning immunity means that even people who caught COVID-19 in May or June, when the BA.4 and BA.5 Omicron subvariants took off, could be susceptible to reinfection with the newest crop of subvariants, assuming they continue to spread.

Disruptive illness

If you are unfortunate enough to be reinfected, it is still likely that your infection will be mild. But mild doesn’t necessarily mean trivial. Not everyone has the benefit of sick pay, or a partner who can take over all childcare duties while their other half quarantines in bed. Even for those lucky enough to have these things, the risk of Long COVID still looms large.

COVID-19 isn’t just about individual risk. There are still plenty of people in our communities who risk being hospitalised, or developing lasting disability, if they catch COVID-19 – even if they’ve been vaccinated. This includes people who may look relatively young and healthy. Living life as if there’s no pandemic is risky – for everyone.

It is also unsustainable. Widespread absences due to COVID-19, flu, or any other infection, risks there being too few teachers, delivery drivers, healthcare staff and other essential workers to keep society running as normal.

Everyone wishes for a return to normal life, but behaving as if there is no COVID-19 will have consequences. Relative normality is another matter. With a few common-sense precautions – such as avoiding mixing with people if you are unwell; wearing a good quality facemask in crowded indoor spaces if local case numbers are high (particularly if you are unwell); taking a COVID-19 test if you can; getting a booster vaccine if you are offered one; and keeping indoor spaces ventilated – we can all help to keep everyone protected.