The United States is currently experiencing a major outbreak of measles, reportedly the worst in three decades. According to the US Centers for Disease Control and Prevention (CDC), the national case count reached 1,288 on Wednesday, although experts believe that numbers are higher.
The biggest outbreak started five months ago in undervaccinated communities in West Texas, where three people have died — two children in Texas and an adult in New Mexico — and dozens of people have been hospitalised across the US.
In a statement, the federal government said the CDC “continues to recommend (measles, mumps and rubella) vaccines as the best way to protect against measles.”
Speaking with the OnlyMyHealth team, Dr Irphan Ali, Paediatrician and Neonatologist, K J Somaiya Hospital and Research Centre, Mumbai, highlights the importance of measles vaccines and booster shots, sharing that two doses are a must.
Also Read: US Reports Highest Measles Case Tally In 33 years; Know More About The Deadly Disease
What Is Measles?
Measles is a highly contagious infection caused by a virus belonging to the Morbillivirus genus within the Paramyxoviridae family. Also called rubeola, measles is considered a serious disease that can cause complications, especially in young children and those with weakened immune systems.
Measles is spread through respiratory droplets, and the virus can remain active and contagious for a couple of hours in the air or on surfaces.
Common symptoms include fever, cough, runny nose, and red, watery eyes, also known as conjunctivitis. Some may also develop a characteristic rash that typically appears 3-5 days after the initial symptoms. The rash usually starts on the face and spreads downwards. In some cases, Koplik's spots, small white spots inside the mouth, may appear before the rash.
Role Of Measles Vaccination
Dr Ali says, "The measles vaccine is often given as part of the MMR (Measles, Mumps, Rubella) vaccine in two doses.” Experts believe vaccination significantly reduces the risk of measles infection, hospitalisation, and death, while also preventing the spread of the disease to vulnerable populations.
According to the World Health Organization (WHO), measles vaccination prevented more than six crore deaths between 2000 and 2023.
The global health body recommends two doses of the vaccine for children to ensure they are immune. "The first dose is usually given at 9 months of age in countries where measles is common and 12–15 months in other countries. A second dose should be given later in childhood, usually at 15–18 months."
When Is Measles Booster Shot Recommended?
As discussed, measles vaccination is administered in two doses. “The first dose is often administered at 9–12 months, and the second at 15–18 months or prior to school age (4–6 years),” says Dr Ali.
He adds that booster doses are sometimes administered in outbreak situations or high-risk environments to adolescents and adults who are unvaccinated or incompletely vaccinated.
It is important to complete the two-dose vaccine administration, as one dose only gives approximately 93% immunity, but two doses give around 97%. That's why the second dose, or booster, is so important. Without the second dose, people can still be at risk, particularly if they are exposed to the virus if there is an outbreak.
Also Read: US Measles Outbreak: Nearly 1,200 Cases Reported, 34 States Affected, And 3 Deaths
Measles Booster Shot During An Outbreak
According to Dr Ali, booster injections are a critical factor in limiting spread, especially during epidemics. “Booster injections increase herd immunity and safeguard both vaccinated people whose protection might have declined and immunocompromised individuals who cannot be vaccinated.”
Boosters ensure protective antibodies are re-established in a timely manner to avoid severe disease or transmission.
Who Should Get A Measles Booster Shot?
Generally, most people who have received two doses of the MMR vaccine are considered protected for life and don't need a booster shot.
However, certain individuals may need a booster, including those who were vaccinated before 1960, healthcare personnel, international travellers, and those in areas with measles outbreaks.
Additionally, those with weakened immune systems or those who have been exposed to measles may need additional doses.
Can People Who Aren’t Aware Of Their Vaccination Status Get Measles Vaccine?
The short answer is “Absolutely”. “If two doses have not been documented and the person is not immunocompromised, it is safe and advisable to receive a booster. There are no severe side effects from an additional dose.
In public health parlance, it's much better to be safe and protected than to risk infection during a surge, concludes Dr Ali.