Unsure about measles and vaccines? Here’s the expert guide

Australia is experiencing an increase in the number of cases of measles, but the US has had more serious outbreaks. Our GP columnist takes you through the latest on the disease and how to prevent its spread.

DR MAGDALENA SIMONIS

An unvaccinated person who is exposed to measles is 90 per cent likely to contract the disease from droplets spread through the air or contaminated surfaces. Picture: Getty Images

8 min read

16 hours ago.

Updated 8 hours ago

Measles cases in Australia continue to climb, and the latest reports from Western Australia bring the number to about 80, across all states and territories.

The detection of measles in flight staff and a few miners in a remote mining town in WA, coupled with the recent announcement of suboptimal childhood and adolescent immunisation rates, raises concerns around the potential for a return of the measles epidemic we witnessed prior to the 1970s vaccination program.

Most people these days don’t realise how contagious or serious measles is; in fact, it is one of the most contagious diseases in the world. An unvaccinated person who is exposed is 90 per cent likely to contract the disease from droplets spread through the air or contaminated surfaces – and the incubation period, which is when a person is asymptomatic but contagious, can be anywhere from seven to 18 days.

A person with measles will infect 12 to 18 others on average, as compared to a person with Covid-19, who can infect about three people on average.

Measles was almost eradicated in Australia and was no longer an endemic disease by March of 2014, although there were occasional cases brought back by travellers returning from countries with low vaccination rates, much like we are seeing now.

So, given it never really disappeared in the first place, why is such a ruckus being made about it?

There is valid cause for concern from what we are seeing unfold in the US as the number of measles cases reported on July 15 has surpassed 1309, with three confirmed deaths, reaching a 33-year high. This rise in infections is partly due to vaccine hesitancy, which is strongly driven by widespread vaccine misinformation, although this might not be the only explanation for the cases we are seeing in Australia.

The 20 to 49-year-old age group is heavily represented among the recent measles cases in Australia, due to incomplete vaccination and overseas travel, usually to southeast Asia where national uptake of vaccinations is lower.

Catching up with family and friends or just returning to work or university after a holiday escape can expose those who are at greatest risk, which is children under 24 months along with other under-vaccinated adolescents, young adults and pregnant women.

Those born before 1966 from countries with similar national vaccination programs to Australia are assumed to be immune to measles due to the national immunisation programs that were in place throughout schools at that time and the measles epidemics that swept across the globe.

If you come from another country and are not sure about your vaccination status, it is safe to get another vaccination – although a blood test can confirm your immune status. Those who contracted measles are considered immune for life, as are those who have received two vaccinations, which provide 99 per cent lifelong immunity.

Declining vaccination rates are a concern for population health

Since Covid-19, Australian childhood and adolescent vaccination rates have fallen short of the 95 per cent World Health Organisation recommendation and it’s a trend we are seeing across the globe. The latest Australian childhood immunisation rates are 92.14 per cent for one-year-olds, 90.44 per cent for two-year-olds and 93.63 per cent for five-year-olds.

These are the lowest rates we have seen since 2016, which is concerning because herd immunity requires 95 per cent vaccination rates against preventable communicable diseases such as polio, tetanus, measles, rubella, diphtheria, haemophilus influenza, and pertussis.

Herd immunity protects the most vulnerable who can’t have vaccines for a variety of reasons, those where vaccination has been ineffective and people, especially children under two years, who are not yet fully vaccinated.

One can reasonably say that the highest risk at present is from overseas travel. However, despite our overall effective immunisation campaigns, we do risk facing another measles epidemic if national efforts fail to improve our vaccination uptake rates.

What is measles and how does it present?

There are two types of measles: the measles which we are witnessing a resurgence of is caused by the virus “rubeola”, and the other is called “rubella” (formerly “German measles”). They are two distinct viruses with different presentations and complications. Measles is usually a more severe viral illness with potential complications such as pneumonia, encephalitis and even death. Rubella is a milder viral illness but causes severe birth defects in unvaccinated pregnant women.

The first symptoms of measles (rubeola) are fever, sore throat, runny nose, red stinging eyes and dry cough. At first this can appear like a severe viral illness of any kind, until the characteristic rash appears. The flat, spotty rash over the torso and face is a typical feature of measles and usually appears four days into the infection. The spots then coalesce to form a generalised redness on the face and body and there can be small white spots on the inside of the mouth and throat called Kolpiks spots.

Secondary complications are more likely to affect unvaccinated adults and young children, rather than adolescents and young adults. These are usually severe and include middle ear infection, pneumonia (one in 15), and even a serious form of brain inflammation called encephalitis (one in 1000).

An early warning sign of measles-related encephalitis is severe headache and irritability which can progress, causing behavioural changes, confusion and convulsions. Lasting intellectual disability occurs in 40 per cent of those with encephalitis, and 10 per cent will die from the inflammation. It’s a devastating disease and can sometimes lead to subacute sclerosing panencephalitis, or SSPE, which is a rare immune-mediated deterioration of the brain that develops six to 15 years later. So for those who fear the measles vaccine, it’s important to understand that the risk of vaccine-related encephalitis is 1000 times lower, at a rate of 1 in a million, than catching the disease and leaving it to chance. Having the vaccine is much safer than having the disease.

A five-year-old boy battles measles, with the telltale rash on his face. Picture: Getty Images

What to do if exposed to measles

If you have been exposed and are not sure what to do, see your general practitioner within 72 hours for post-exposure prophylaxis. Diagnosis is made by clinical presentation and laboratory testing which includes taking swabs of the throat and nasal passages for PCR (polymerase chain reaction) and blood for serology testing and the presence of antibodies.

The serology test measures immunoglobulin levels which can detect recent infection (IgM) or long lasting immunity (IgG), due to previous infection or immunity. PCR tests are most sensitive within the first few days after the rash appears. Serology testing for IgM antibodies may need to be repeated if negative in the early stages of the illness.

It is a reportable disease, so we can track its progress through the community and it is important that you notify your contacts immediately and get them to see their doctor.

As with other viral illnesses, symptomatic relief is recommended along with rest, fluids, simple analgesia and isolation for up to four days after the rash appears. Those who have been in contact with a case might need to isolate for up to 14 days after the last contact with the infectious person.

It’s important to know your vaccination status but if uncertain or unvaccinated, the measles mumps rubella vaccine (MMR) should be administered within 72 hours of exposure, as this can reduce the severity of infection or even prevent it. The MMR vaccine is government-funded for people born on or after 1966. Make sure you isolate from others to prevent spread and notify your contacts also.

Immunoglobulin can be administered within six days to those unable to have the vaccine, or who are beyond the 72-hour window, or if they are immunocompromised, are a pregnant woman, or an infant.

Measles Mumps Rubella vaccine MMR – it’s a triad

It’s important to know that the measles vaccine is delivered as a triad along with mumps and rubella combined. This means that if a child or adolescent misses their measles vaccine, they’re not getting the mumps and rubella vaccines either.

One of the greatest successes of the national immunisation programs in all nations has been the prevention of congenital rubella syndrome, which is a cluster of birth defects that occur when pregnant women contract the virus. The rubella virus can cross the placenta, infecting the unborn child and causing disastrous complications such as nerve deafness, heart deformities, mental retardation, spasticity, paralysis, cataracts and blindness, as well as miscarriage and late-pregnancy fetal loss, to name a few. The impact of rubella is worse the earlier in the pregnancy the woman is exposed, and the best way to prevent this is to be fully vaccinated prior to pregnancy. The measles mumps rubella vaccine cannot be given when pregnant.

Vaccination recommendations (Australian Immunisation Handbook)

Know your vaccination status

It is important that you ascertain your immunisation status. This can be accessed from the Australian Immunisation Register inquiries line (1800 653 809), or you can access this from your electronic health record.

The catch-up vaccination program for children up to the age of 10 years can be accessed here:

https://immunisationhandbook.health.gov.au/contents/catch-up-vaccination#using-the-catchup-worksheet-for-children-aged-10-years

Children who have not received a measles-containing vaccine at the recommended schedule points may need an alternative schedule

Catch-up vaccination for measles

Measles-containing vaccine is recommended for:

Children ≥12 months of age
Adolescents and adults born during or since 1966 who have not received two doses of measles-containing vaccine, particularly
– healthcare workers
– childhood educators and carers
– people who work in long-term care facilities
– people who work in correctional facilities
– travellers

Children:

Measles-containing vaccine is recommended for children

at 12 months of age as MMR (measles-mumps-rubella) vaccine, and
at 18 months of age as MMRV (measles-mumps-rubella-varicella) vaccine.

Measles-containing vaccines are not routinely recommended for infants younger than 12 months of age. This is because maternal antibodies to measles persist in many infants after birth, declining progressively over the first year of life. These may interfere with active immunisation before 12 months of age.

Adolescents and adults:

All adolescents and adults born during or since 1966 should have either:

documented evidence of two doses of measles-containing vaccine given at least four weeks apart and with both doses given ≥12 months of age, or
serological evidence of immunity to measles, mumps and rubella

People born before 1966 do not usually need to receive measles-containing vaccine (unless serological evidence indicates that they are not immune). This is because circulating measles virus and disease were very prevalent before 1966, so most people would have acquired immunity from natural infection.

Travel

For travel purposes now, it is important to ensure that you are fully vaccinated against measles and have the MMR vaccine at least two weeks prior to departure. The vaccines provide full protection and should be administered 28 days apart.

Travellers born during or since 1966 are recommended to have received two doses of measles-containing vaccine.

Associate Professor Magdalena Simonis AM is a leading women’s health expert and adviser, a senior honorary research fellow at the University of Melbourne department of general practice, and a longstanding member of the Royal Australian College of General Practitioners’ expert committee on quality care.

This column is published for information purposes only. It is not intended to be used as medical advice and should not be relied on as a substitute for independent professional advice about your personal health or a medical condition from your doctor or other qualified health professional.