COVID-19: WHAT RISKS REMAIN IF YOU ARE DOUBLE-VAXED?

From PHE study

The vaccination programme against COVID-19 in England has been an outstanding success.  Hospitalisations and deaths in this wave dramatically reduced compared to previous waves when people weren’t vaccinated. 

But what does it mean to you as an individual to be double-vaxed, whilst infection rates are high?  Unfortunately the vaccines are not perfect so there are residual risks.  How big are they?  Do they matter compared to the benefits of an activity?:

• Chances of catching COVID-19
• Chances of passing it on to family, colleagues and other contacts, 'transmission'
• Chances of hospitalisation and death
• Chances of being left with long-term symptoms, ‘Long Covid’

Let’s look at each of these risks in turn, in the context of the now highly dominant Delta variant.  As was shown at the press conference on 19 July the extra ease with which Delta spreads means cases have been rising as quickly as in past waves, despite many people being vaccinated:

Until this wave of infections is over, and infection rates are back down to a very low level, there are still significant residual risks as follow.

CHANCE OF CATCHING COVID-19

Andrew Marr

We've recently seen 'breakthrough cases' of double-vaxed people suffering COVID-19.  Sajid Javid, the Health Minister, recently contracted COVID-19 despite being double-vaxed.  As did the BBC’s Andrew Marr, who said he had felt “pretty much invulnerable” before contracting the disease.  Certainly not.  He then felt seriously ill for several days.  A nastier, more disruptive disease than flu.

A study by Public Health England highlighted initial risks with the Delta variant compared to being unvaccinated:

• 1 in 3 for AstraZeneca
• 1 in 8 for Pfizer

The difference is not necessarily a measure of the relative effectiveness of the two vaccines.  AstraZeneca has been given mainly to older and otherwise more vulnerable people, Pfizer to younger. It will be good to see an assessment analysed by age, sex and other key factors.

In any case we’re talking risks comparable to 6-barrel Russian roulette.  Not many people would take that risk.  Worth being careful.  Especially the Clinically Extremely Vulnerable, whether or not they have been double-vaxed.
 

CHANCES OF TRANSMISSION

As noted above, Delta is more transmissible than earlier variants.  That means once you’ve caught COVID-19, even if you are yet to show symptoms, you can more easily pass on the virus to other people.  As above, they can then develop it even if they are double-vaxed.

Indeed there is now evidence that people who have had COVID before can catch it again, especially now there is a different more powerful variant in circulation.  Hence PM Johnson and other members of the Government self-isolating who had been in contact with Javid.

As you can be infectious before developing symptoms, it’s worth continuing to wear a mask in crowded situations.  Just in case, to protect those around you.
 

CHANCES OF HOSPITALISATION AND DEATH

As noted above, the chances of hospitalisation compared to not being vaccinated are for better, on average:

• 1 in 12 for AstraZeneca
• 1 in 20 for Pfizer

Whilst symptoms can thankfully be easier to treat if double-vaxed, death can still occur.  Nasty.

CHANCES OF LONG COVID

Everyone who catches COVID-19 has a chance of developing symptoms that last for over three months, and sometimes over a year. 

Symptoms are many and various, and can be painful and totally debilitating. Some people not being able to return to work, or struggle to work.  

Children affected too.

 

The symptoms are in four groups:

• Continuation of basic COVID-19 symptoms such as lung problems
  
• Post-viral fatigue, as can happen after any severe viral infection
• Pain and discomfort, or loss or impairment of bodily function, when the virus spreads around body and attacks other organs.  Symptoms such as heart palpitations.  Possibly the cause of brain fade too, which is commonly reported.
  
• Resulting mental health issues, such as depression and anxiety

We don’t yet know if the Delta variant cause more or less problems than earlier variants.  Indeed it could be worse, due to the variant’s increased power to infect.  But if we assume Long Covid rates are comparable, then the Kings College ZOE study from last year gives a good indication for those who have symptoms.  Around 1 in 50 suffering for longer than 12 weeks.  1 in 7 for at least 4 weeks.  Maybe higher with Delta.

Further details on Long Covid are here.  Given the huge numbers of people impacted, somewhere in the region of 1 to 2 million, it is disappointing that SAGE is only just including it in their deliberations.

IN SUMMARY

On average for people double-vaxed, it is far better than being unvaccinated, so worth being vaccinated.  But there are a number of residual risks, so it is not a matter of being 'invulnerable':

• Around 1 in 5 will still get infected by Delta compared to being unvaccinated, depending on vaccine, age, sex and other factors
• Each of these people can pass on the virus to other people, even when not displaying symptoms.  So wearing masks is still worthwhile in crowded places to protect others
  
• The chance of hospitalisation and death is far better when double-vaxed, but is not zero
• The chances of Long Covid for those catching Delta are probably at least 1 in 7 with symptoms lasting beyond four weeks.  Then 1 in 50 for more than three months.  The symptoms can be painful and debilitating, and stop people returning to work. 

Depending on your activity, you may regard these risks as acceptable.  But as a double-vaccinated individual, it's well worth you maintaining basic precautions.   'Hands Face Space'.  Avoiding crowds, especially indoors, and continuing to wear a mask to help protect others.