Covid booster side effects: Everything you need to know about third jab

Kate Ng
·4 min read
(PA)
(PA)

The NHS is continuing to ramp efforts to hand out more Covid booster jabs to protect the British public against the spread of the Omicron variant.

The NHS vaccination programme is sending out around 650,000 text messages and 50,000 letters to people who have not yet received their third dose of a Covid vaccine.

According to the government’s latest figures, roughly 36 million people in the UK have had a third jab.

But as Britons continue getting jabbed, many may be wondering what the side effects of a booster jab will be, with new reports claiming that the most common appears to be swollen lymph nodes.

Here is what you can expect when you get your booster jab:

Which vaccine will I get for my booster dose?

Every person who is eligible for a third dose of a Covid vaccine will be given either the Pfizer or Moderna vaccine.

You can have either vaccine even if you were given the AstraZeneca vaccine as a first and second dose.

According to the UK Health and Security Agency (UKHSA), both vaccines have been proven to boost the immune system well and have already been administered to millions of people in the UK.

The agency advises that people “will be offered the right vaccine for you, which may be the same or different from the vaccines that you had before”.

What are the common side effects of a booster jab?

Most of the side effects that people may experience from a third jab are the same as those experienced with all other Covid vaccines used in the UK.

The most common side effects include:

  • Sore, heavy arm where you had your injection

  • Fatigue

  • Headache

  • General aches or mild flu-like symptoms

  • Feeling feverish

According to the NHS, these symptoms may last around one or two days after vaccination. You can take painkillers, such as paracetamol, to ease any discomfort.

However, new reports have emerged of swollen lymph nodes being a side effect.

Lymph nodes, or lymph glands as they’re called, are small lumps of tissue that contain white blood cells. There are hundreds of them in the body and they can fight infections by attacking and destroying germs that are in the lymph fluid.

According to a vaccine weekly safety report issued by the Australian government, swollen lymph nodes is the most common adverse side effect reported to its health department.

“This is a normal and known side effect of vaccines and occurs when the immune system is stimulated,” the report explains. “Swollen lymph nodes were observed in the clinical trials. For Comirnaty (Pfizer), this occurred more frequently after a third or booster dose (five per cent of people) than after the first or second doses (less than one per cent of people) in the clinical trials. For Spikevax (Moderna), this occurred in up to 1 per cent of people.

If you experience other side effects, you can report them on the Yellow Card Coronavirus Reporting Site, which helps the Medicines and Healthcare products Regulatory Agency (MHRA) ensure safe and effective use.

Are there more serious side effects from a booster jab?

In very rare cases, some people may have a serious allergic reaction to the vaccine. If you’ve ever had a serious allergic reaction before, including anaphylaxis, you must tell healthcare staff at the facility where you are receiving your booster jab.

The staff may ask what you’re allergic to to ensure you can have the vaccine. If you do have a reaction, it usually happens within minutes and staff are trained to treat them immediately.

There have also been rare cases of heart inflammation (myocarditis) reported following a Covid jab, mostly in younger men within several days of receiving a vaccine.

In most of these cases, patients have recovered and felt better after resting and receiving simple treatments.

You should seek medical advice immediately if you experience any of the following symptoms after vaccination:

  • Chest pain

  • Shortness of breath

  • A fast-beating, fluttering or pounding heart

How can I book my booster jab?

If you are eligible for a Covid booster jab, you can book an appointment online or call 119 to make an appointment.

You can also visit a walk-in vaccination site to get a jab. Find out more here.