7 questions parents ask about childhood vaccines on Mumsnet

Vaccinating your child is one of the most effective ways to protect them from serious illnesses. But, as a parent, it’s completely understandable to have questions, especially given the recent changes to the NHS vaccination schedule.

On Mumsnet, parents regularly discuss everything from side effects and safety to why certain vaccines aren’t yet routine. Many are keen to follow the schedule but want to understand exactly what each vaccine does, while others seek space to ask honest questions without judgement. 

Using mumsGPT+ (Mumsnet’s AI tool shaped by two decades of invaluable parenting wisdom), we’ve examined thousands of vaccine-related discussions on the Mumsnet forums over the last year and have pinpointed the questions that come up time and time again*. 

1. “I'm just looking for a bit of advice on which of these vaccinations are [100%] necessary. I feel that 4 injections at once is [a lot] and want to refrain from causing my child any unneeded pain and discomfort,” shares CharlotteJB

The number of vaccines in the NHS vaccination schedule is a common concern for parents, particularly when it comes to newborns.

The NHS vaccination schedule is designed to protect babies when they are most vulnerable, with the first vaccinations given at 8, 12 and 16 weeks old. 

According to the UK Health Security Agency (UKHSA), the schedule is based on: 

• When babies' immune systems can best respond to vaccines

• When children are most at risk from certain diseases

• Scientific evidence about the safest and most effective timing to be vaccinated. 

Newborns and young infants have immature immune systems, which means they can’t fight off serious infections as effectively as older children and adults. However, vaccines work with your baby’s natural immune system. The vaccinations given in the first two years of your baby’s life contain far fewer antigens (parts of germs that help your body build immunity) than your baby’s immune system deals with every day. There is no risk of giving too many vaccines for your baby’s immune system to cope with. Spacing out vaccines doesn’t offer any medical benefit and delaying them can mean your child won’t be protected when they are most vulnerable to catching these diseases and could get seriously ill.

The schedule has been carefully designed so that vaccines are given at the time when they offer the most effective protection. For example, from July 2025, the MenB vaccine (which protects against meningitis B) is now given at 8 and 12 weeks instead of 8 and 16 weeks, because the most up to date evidence that we have is that babies in their first few months of life are the most vulnerable to this infection. 

Individual vaccines (such as separate measles, mumps,  rubella, and chickenpox vaccines instead of the combined MMRV) are not routinely offered on the NHS because: 

• The combined vaccine has been proven safe and effective

• Giving individual vaccines would mean more injections for your child

• It would leave your child unprotected for longer between doses

• There is no safety benefit to having them separately

Common side effects are usually mild

2. “My DS was very upset and unsettled for a week after his 12 week vaccinations and I’d wish I’d known about that being quite common at the time. How are babies normally with their one year vaccines please?” asks veggietate

For many parents, not knowing what’s common in terms of side effects or how their child might react to routine vaccinations can make the experience feel unsettling.

All vaccines used in the UK have been thoroughly tested for safety. They are only approved after passing strict tests and they continue to be monitored after they are introduced. 

According to the NHS, common side effects are usually mild and include: 

• Redness, swelling or tenderness where the injection was given

• A mild fever (temperature above 37.5°C)

• Being unsettled irritable or crying more than usual

• Feeling tired or not wanting to eat

These side effects usually last a day or two and are a sign that your baby's body is building protection. Knowing what’s common - and when symptoms might appear - can help reduce worry, especially once you’re back home after the appointment.

When delayed symptoms appear, this doesn’t usually mean anything is wrong, but it’s OK to check in with your GP if you have any concerns.

Serious side effects are extremely rare. The risk of a serious reaction to a vaccine is much lower than the risk of serious harm from the disease itself.

Before a vaccine is approved, it goes through: 

1. Laboratory testing

2. Clinical trials with thousands of people

3. Review by independent experts

4. Ongoing safety monitoring once in use

The Medicines and Healthcare products Regulatory Agency (MHRA) oversees vaccine safety in the UK and investigates any reports of side effects. 

If you or your child experiences an adverse reaction to a vaccination, you can report it via the MHRA Yellow Card Scheme. 

3. “Can [my child] have [their vaccinations] at any time during their third year?” asks this Mumsnet user

Many parents wonder about flexibility around vaccination timings, for example if an appointment is missed or needs to be delayed. 

The NHS vaccination schedule is designed to give your child protection at the times when they are most at risk. This is why the NHS generally recommends that parents follow the schedule wherever possible.

According to UKHSA, vaccines should not be given before the scheduled age unless there is a clear medical reason, such as travel to a country where a disease is common.

Vaccination against chickenpox (varicella) became routine in January 2026 as part of the combined MMRV vaccine

4. “We are thinking of getting the chickenpox vaccine for our 1.5 year old [...] Has anyone had this vaccine for their child? Would you recommend?” asks Starry4321

Parents frequently ask about chickenpox vaccination. From January 2026, protection against chickenpox (also called varicella) will be routinely offered free on the NHS as part of the childhood vaccination schedule. 

Why the change? 

The Joint Committee on Vaccination and Immunisation (JCVI) reviewed the evidence and recommended adding chickenpox to the routine schedule because:

• Chickenpox can cause serious complications, especially in young children, and children could then spread the disease onto those who are vulnerable like pregnant women and people with weakened immune systems.

• Complications can include bacterial skin infections, pneumonia, brain inflammation, and in rare cases can be life-threatening.

• The vaccine has been used safely for decades in countries like Canada and Germany.

• Evidence shows vaccination significantly reduces cases of illness and hospital admissions.

What will happen from January 2026?

From 1 January 2026, children will receive a combined MMRV vaccine (measles, mumps, rubella and varicella) instead of just MMR. When they were born will determine when they’ll have their vaccination. 

If your child is born on or after 1 January 2025:

• First dose at 12 months

• Second dose at 18 months

If your child is born between 1 July 2024 and 31 December 2024:

• They should have already received their first MMR dose at 12 months

• They will receive MMRV at 18 months and again at three years four months

If your child is born between 1 September 2022 and 30 June 2024:

• They should have already received their first MMR dose at 12 months

• They will receive one dose of MMRV at three years four months (instead of their second MMR dose)

There will also be a catch-up programme for older children. Between November 2026 and March 2028, children aged three years four months to under six years who haven't had chickenpox or the varicella vaccine will be offered one catch-up dose of MMRV.

For more information, NHS.uk’s guide to the introduction of routine varicella vaccinations for children.

5. “Does my baby have to have his one year vaccinations when he is exactly a year old, e.g. in the same week that he turns one?” asks StarlightDreamer

In most cases, vaccinations follow a set timetable based on your child’s age, with some flexibility around appointment dates. There are certain circumstances where your child may be able to have their vaccinations earlier or later. 

Early vaccination

Vaccinations can sometimes be given early in special circumstances, such as: 

• Travelling to a country where a disease is common

• During a disease outbreak

• If there is a medical reason your child needs earlier protection

The first set of vaccinations can be given from six weeks of age if needed for travel to an area where diseases are common. Your GP practice will advise if this applies to your situation.

Delayed vaccination

If your child is unwell with a high fever (temperature above 37.5°C), their vaccination may need to be delayed. Minor illnesses without a fever, such as a cold, don’t usually mean an appointment has to be postponed, but do check with your GP practice if you’re unsure.

If your child misses a vaccine appointment, don’t worry. Missed appointments can happen for a variety of reasons. Simply book another appointment as soon as you can. The schedule doesn't need to be restarted - your child will just continue from where they left off.

What if my child is behind on vaccines?

You can contact your GP practice to catch up. They can check your child’s records, explain what’s due next and help you get back on track without needing to restart the schedule.

Missed one of your child’s vaccines? Speak to your GP practice to catch up 

6. “Should non-vaccinated children be limited from accessing nursery or schools (as in other countries)?” asks MidnightPatrol

In the UK, vaccination is not legally required for children to attend nursery or school. Parents can choose whether or not to vaccinate their children. 

However, some parents want to understand how vaccination levels can affect environments like schools and childcare settings, particularly during disease outbreaks.

Herd immunity (community protection)

When enough people in a community are vaccinated it helps protect those who cannot be vaccinated, such as: 

• Babies too young for vaccines

• Children with weakened immune systems

• People with certain medical conditions

• Elderly people

The level of uptake required depends on how infectious the disease is, and how effective the vaccine is. When vaccination rates drop below this level, diseases can spread more easily, which is why public health teams monitor uptake and respond during outbreaks.

The current situation

Vaccination rates in the UK have been falling. The UKHSA has expressed concern that not enough children are protected, which increases the risk of outbreaks of diseases like measles. From Autumn 2023 to summer 2024, England experienced the biggest outbreak of measles since 2012, particularly affecting young children. Since the peak in 2024, cases have declined but local outbreaks continue.

7. “Does anyone know why [the HPV vaccine] is recommended as standard for children from 11 years? Is it because there is [a] perceived realistic risk of sexual contact occurring from this age?” asks nooshoo

It’s understandable for parents to question when a vaccine is offered earlier than they expected or when vaccination guidance changes. 

The HPV (human papillomavirus) vaccine is offered to children aged 12 to 14 (school Year 8 in England) because this is the best time to give it. 

Why not earlier?

The vaccine works best when given before exposure to HPV, which is spread through sexual contact. By vaccinating at age 12 to 13: 

• The vaccine is given before most people become sexually active

• Young people's immune systems respond very well at this age

• One dose is now known to be sufficient for children under 15 (older people need two doses)

How long does the protection last?

The vaccine provides long-lasting protection. Studies show it remains effective for at least 10 years, and evidence suggests protection continues beyond this. You do not need additional doses.

Who does it protect?

The HPV vaccine is offered to both boys and girls because HPV can cause several types of cancer:

• Cervical cancer (in women)

• Anal cancer

• Some head and neck cancers

• Genital cancers

Final thoughts

Childhood vaccines protect children from illnesses, but it’s understandable for parents to have questions along the way. Understanding how the NHS vaccination schedule is designed, what side effects to expect and what to do if appointments are delayed can help you feel more confident and supported.

If you’re feeling unsure at any point, you’re not alone. If you’d like tailored advice, speak to your GP, health visitor or practice nurse. They’ll be able to talk you through your personal circumstances and answer anything not covered here. You can also find information on the NHS website.

*mumsGPT+, 8 December 2024 to 8 December 2025