Had a COVID vaccine? You still need to protect yourself and others afterwards

February 11, 2021

This article has not been updated recently

As COVID-19 vaccines roll out across the UK, hopes are building that life might start getting back to some kind of normality. 

But it’s essential to remember that even once you’ve had a jab, you still need to protect yourself and those around you from COVID-19.

Here’s why.

You’re not instantly immune after your first COVID-19 jab

It takes at least two weeks for any immunity to start building up after your first vaccine dose, so you are still at risk of catching and passing on the coronavirus during this time. 

Even though people who have already had COVID-19 may be less likely to catch it again, it’s still possible to be reinfected and give it to others.

“For those first two weeks in particular, you should assume that you’re totally unprotected - you can still easily catch COVID-19 and you can still pass the virus on to others around you,” explains Tim Spector, ZOE COVID Symptom Study lead. 

“Many people will feel relieved after getting vaccinated and relax their guard, but it’s really important to keep following the government guidelines on social distancing, hand hygiene and wearing a mask after your first vaccine dose.”

The latest data from the app suggests that although a reasonable level of immunity builds after two weeks - with 50% protection after a fortnight and 67% protection after three weeks - the three current UK vaccines (Pfizer/BioNTech, Oxford/AstraZeneca and Moderna) all need two doses to achieve maximum protection. 

But remember...

No vaccine provides 100% protection - it’s best to play safe

No vaccine guarantees you 100% protection against COVID-19, especially for very elderly people. We are still seeing mild cases in those who have been vaccinated, so it’s sensible to continue to reduce your exposure to the virus, particularly while rates are still high in many parts of the UK. 

While we know that vaccines are effective at preventing illness, hospitalisation and deaths from COVID-19, we don’t know for sure how good they are at preventing people who have been vaccinated from passing on the virus without feeling unwell (known as asymptomatic transmission). 

Although the data so far is generally reassuring at present, we also don’t know how effective vaccines will be at protecting against all the new variants of the coronavirus arising in the UK or coming in from overseas.

Even if you’ve been vaccinated, it’s going to take a while for the rest of the population to catch up. And some people can’t be vaccinated for health reasons, leaving them vulnerable to infection while the virus is still circulating. 

We need at least 60-70% of the population to be vaccinated in order to provide enough community immunity to protect everyone.

“Until we’ve brought the levels of COVID-19 right down in the UK it’s still necessary to protect yourself and others around you, especially if they haven’t been vaccinated,” says Tim. 

“Sticking to public health guidelines will not only help to stop the spread of COVID-19 and bring the pandemic to an end, but it will also cut your chances of catching seasonal colds and flu, which are also around at this time of year.”

The after effects of vaccination, such as fatigue and headache, can feel a lot like COVID-19 symptoms. We are seeing plenty of cases of COVID-19 in people who have just been vaccinated, so if you’re logging your symptoms in the ZOE COVID Symptom Study app after getting your jab and are offered a test, please take it! 

When can I hug my family again?

This is a question we all want to know the answer to. It’s been a really tough year and so many of us have lost loved ones along the way, so it’s tempting to go and hug everyone as soon as you’ve had your jab. But this may not be a good idea.

“There is always going to be some risk involved. While we know that there is partial immunity from a fortnight after the first dose, we still don’t know how well vaccines prevent transmission so people need to use their common sense,” says Tim. 

“If you can, it’s safest to wait until more than 60% of the population have been vaccinated with the second vaccine dose, especially for the elderly and those with underlying health conditions.” 

The good news is that rates of COVID-19 are falling across the UK in response to lockdown, with a 80% drop in cases since the peak around New Year. At the same time, millions of people are being vaccinated every week

“This is a highly contagious virus and it’s likely that there will be some level of restrictions in place for many months to come to guard against the resurgence of new variants,” Tim explains. 

“But if things continue improving in the same direction, we should be in a much better place by the summer - we just need to take care now to make sure we get there.”

If you’ve had a COVID-19 vaccine, be sure to log it in the ZOE COVID Symptom Study app to help us understand the after effects and impact of vaccination. 

Remember: while cases are high any unusual symptom could be COVID-19 - even after your jab - so log it in the app and get a test to be sure.

Stay safe and keep logging. 

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