AstraZeneca vaccine: side effects of first and second dose - and blood clot and stroke risk explained

The UK medicines regulator advices people seek medical help if symptoms persist for more than four days

People under the age of 40 are now being offered the Pfizer or Moderna vaccine, or another Covid-19 jab that becomes available on the UK’s vaccination programme, instead.

Sign up to our NationalWorld Today newsletter

The i newsletter cut through the noise

The decision to stop administering the AstraZeneca vaccine to this age group comes after the MHRA said the balance of risk for the jab is very favourable for older people, but is “more finely balanced” among younger groups, who do not tend to suffer serious illness from coronavirus.

Separately, a review by the European Medicines Agency (EMA) concluded that “unusual blood clots with low blood platelets should be listed as very rare side effects” of the Oxford/AstraZeneca vaccine.

Doctors are also being urged to look for signs of a stroke in people who receive the AstraZeneca vaccine, after three young patients were admitted to hospital after their vaccination, and one sadly died.

Health experts, including from the National Hospital for Neurology and Neurosurgery at University College London (UCL) Hospitals NHS Foundation Trust, told how two women in their 30s and a man in his 40s suffered blood clots in their large arteries, leading to ischaemic stroke.

Experts stressed the chances of suffering a stroke were small, but the team has advised the NHS to look out for patients with signs of ischaemic stroke within around one month of vaccination. Anyone who suffers any signs of a stroke should be “urgently evaluated” for a very rare syndrome called vaccine-induced thrombosis and thrombocytopenia (VITT).

Most side effects from the vaccine are mild to moderate (Photo: Getty Images)

But what can people expect after getting the vaccine? Here’s what you need to know about possible side effects.

What are the side effects of the AstraZeneca vaccine?

Some people may experience side effects after receiving the AstraZeneca Covid-19 vaccine.

In clinical studies, most of the side effects were mild to moderate in nature and resolved within a few days, with some still present a week after vaccination. However, side effects do not occur in every case with some people experiencing no symptoms at all.

If you do experience any side effects, these will typically only last for a few days.

The following symptoms are the most common after receiving the coronavirus vaccine, and affect more than one in 10 people. These may include:

- tenderness, pain, warmth, itching or bruising where the injection is given

- generally feeling unwell

- feeling tired (fatigue)

- chills or feeling feverish

- headache

- feeling sick (nausea)

- joint pain or muscle ache

Other common symptoms, which can affect up to one in 10 people, include:

- swelling, redness or a lump at the injection site

- fever

- being sick (vomiting) or diarrhoea

- flu-like symptoms, such as high temperature, sore throat, runny nose, cough and chills

In some cases, people may experience side effects such as swollen glands or dizziness, but these symptoms are much less common and may only affect up to one in 100 people. These include:

- feeling dizzy

- decreased appetite

- abdominal pain

- enlarged lymph nodes

- excessive sweating, itchy skin or rash

In light of the possible link to blood clots, the MHRA is now advising as a precautionary measure that anyone who experiences any of the following symptoms four days or more after vaccination should seek medical advice:

- a new onset of severe or persistent headache, blurred vision, confusion or seizures

- develop shortness of breath, chest pain, leg swelling or persistent abdominal pain,

- unusual skin bruising or pinpoint round spots beyond the injection site

What if I get a fever?

Some people have reported a sudden feeling of cold with shivering and shaking accompanied by a rise in temperature, possibly with sweating, headache, nausea, muscle aches and feeling unwell, starting within a day of having the vaccine and usually lasting for a day or two.

If your fever is high and lasts longer than two or three days, or you have other persistent symptoms, this might not be due to side effects of the vaccine and you should follow appropriate advice according to your symptoms.

Will I get side effects with the second dose?

Side effects after your second dose are likely to be more intense than the ones experienced after the first. This is completely normal and is a sign that your body is building protection against the virus.

It is important to get two doses of the vaccine, even if you have mild side effects after the first dose. In both cases, symptoms should only last for a few days.

Can I take anything for the symptoms?

You can take painkillers, such as paracetamol and ibuprofen, to help ease any post-vaccination side effects you might have.

It is not recommended that you take these medicines before your vaccination for the purpose of trying to prevent side effects.

To reduce pain and discomfort from the site of the injection, you should apply a clean, cool, wet washcloth over the area, and use or exercise your arm.

To help minimise discomfort from fever, make sure to drink plenty of fluids.

When should I see a doctor?

If you notice any side effects not mentioned in the leaflet provided following your vaccination, you should inform your doctor, pharmacist or nurse.

If you are worried about any symptoms you experience, you can phone the NHS 24’s 111 service for help.

Dr June Raine, MHRA chief executive, said: “The public’s safety is always at the forefront of our minds and we take every report of a suspected side effect very seriously indeed.

"We thoroughly analyse each and every report as we receive it and although the number of reports of CVST and other thromboembolic events has increased over the last week, so has the overall number of vaccinations administered, therefore these blood clots remain extremely rare and unlikely to occur.

“We ask anyone who suspects they have experienced a side effect linked with their Covid-19 vaccine to report it to the Coronavirus Yellow Card website.

“It is still vitally important that people come forward for their vaccination when invited to do so.”

A message from the editor:

Thank you for reading. NationalWorld is a new national news brand, produced by a team of journalists, editors, video producers and designers who live and work across the UK. Find out more about who’s who in the team, and our editorial values. We want to start a community among our readers, so please follow us on Facebook, Twitter and Instagram, and keep the conversation going.