Vaccine history, part 1: What can we learn from measles?

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  • A recent survey found that 82% of South Africans on medical aid would get vaccinated for Covid19
  • But if people don’t get vaccinated, new outbreaks can occur and the virus will continue spreading
  • Measles is one of the world’s most contagious diseases. Here’s why looking at its vaccination campaign can hold lessons for South Africa’s mass Covid vaccine roll-out. 

South Africa will soon start with a mass roll-out of Covid jabs — but will people take them and how will they end the Covid pandemic?

A Council for Medical Schemes survey published this month, revealed that 82% of 75 518 medical schemes’ members surveyed reported that they would get vaccinated, while 76% said they would trust Covid shots if someone close to them would get vaccinated.

But what happens when religion or other beliefs interfere with vaccine take-up or if immunisation programmes are run badly and not everyone who needs a jab gets one? There are many lessons we can learn from vaccination campaigns during previous disease outbreaks.

Over the next three weeks, we’ll be looking at how vaccines turned three pandemics into manageable diseases. We’ll also look at the challenges experienced with getting enough people vaccinated and why disease cases surged when vaccination rates dropped. 

Today, we kick this three-part series off with a focus on how jabs helped to bring one of the world’s most contagious diseases — measles — under control.

What the world looked like before the measles vaccine

Early in the 20th century, between 1900 and 1902, South African children held in internment camps during the Anglo-Boer War were dying at alarming rates, according to a study in the American Journal of Epidemiology.

A few years later, in 1911, 13% of residents on the isolated Polynesian island of Rotuma, 500 kilometres from Fiji in the South Pacific, died too, found another American Journal of Epidemiology study. In the same decade, thousands of United States soldiers huddled into ships, succumbed to a rapidly spreading illness on their way to Europe to fight in the first World War. 

The culprit was measles, a highly contagious viral infection that spreads as a result of close contact with people and also through coughing and sneezing. One person infected with the measles virus can spread it to 12 to 18 other people, the US government’s Centres for Disease Control (CDC) estimates.  

Measles infection can cause fever, a sore throat and a skin rash of red blotches that spreads across the whole body, the US-based research organisation, Mayo Clinic explains.

And, the infection can be deadly to children. Pregnant women and unvaccinated people over 30 or with weakened immune systems are also at risk of becoming very ill. 

What the world looked like after the measles vaccine 

Before the measles vaccine was introduced globally in 1963, the disease claimed 2.6-million lives each year.  

The MMR vaccine, which protects against measles, mumps and rubella, is incredibly efficient: two doses, given at least a month apart, are around 97% effective at preventing people from getting sick with measles, and one shot is 93% effective, according to the CDC

The jab resulted in a 73% drop in global measles-related deaths between 2000 and 2018, the World Health Organisation (WHO) estimates

The efficacy of the measles vaccine is nearly on par with two of the vaccines that have been developed to combat Covid-19. The vaccine developed by Pfizer and BioNTech is 95% effective after two doses and Moderna’s jab is 94% efficacious at preventing people from developing Covid after two shots. 

The vaccine’s impact in South Africa

South Africa introduced the measles vaccine in the 1960s, says Melinda Suchard, who heads up the centre for vaccines and immunology at South Africa’s National Institute for Communicable Diseases (NICD). 

The jab has decreased the incidence of measles dramatically to the point where, in most years after its introduction, the country has had only a few measles cases. In 2009, however, a massive outbreak swept the country. The NICD recorded 18 000 cases. 

South Africa recorded only 64 cases of measles in 2019, most of which were among children between the ages of one and four, according to an NICD surveillance report from that year.

The country has seen a number of relatively small outbreaks in the past decade, caused by low vaccine coverage, overcrowding and because people with HIV have a low overall immunity, making them more susceptible to infection. 

One in five of South Africans between the ages of 15 and 49 live with HIV.

Suchard explains: “When vaccine coverage falls, then we see outbreaks again.”The public sector’s Expanded Programme of Immunisation offers a two-dose vaccine that only protects against measles, but the three-in-one MMR vaccine that protects against measles, mumps and rubella (MMR) can be accessed in the private sector.  

Children are only considered to be fully immunised against measles once they receive a second measles shot, and international targets require that between 93 and 95% of a population is vaccinated to achieve herd immunity (herd immunity is when enough people have been vaccinated to stop the virus from spreading from person to person). 

For Covid-19, the South African government says 67% of the population needs to be vaccinated to reach herd immunity — but this is dependent on the efficacy of a particular vaccine and the transmissibility of different variants of the SARS-CoV-2 virus that causes Covid-19 (so the more transmissible a variant is, the higher the proportion of people who need to get vaccinated becomes and the less efficacious a vaccine is, the higher the percentage of a population that requires a jab becomes).

South Africa’s vaccination rates for measles are, however, far below the requirement for herd immunity: Fewer than 60% of local children received the second jab in 2019, according to 2019 WHO surveillance data, although government estimates provided to the United Nations body put the figure at about 80%.

The Health Systems Trust’s 2017 District Health Barometer, however, estimated that only 72% of South African children received their booster measles shot. The authors explain: “The first measles shot has a failure rate of 15%, so the second dose is important as a booster.” 

In 2017, the NICD recorded measles outbreaks in Gauteng, KwaZulu-Natal and the Western Cape, according to that year’s annual surveillance report for measles

Gauteng recorded 96 cases in total, and most of them were unvaccinated primary school children whose parents were hesitant about vaccines.

How deaths have increased because of low vaccination rates

It’s not only South Africa’s measles vaccination rates that are low. Half a century after the measles vaccination was introduced, the infection is on the rise again. 

Between May and October 2020, the CDC recorded 7 476 cases in ten countries. This is expected to increase because 41 countries have suspended vaccination programmes in the wake of the coronavirus pandemic.

Global deaths from measles climbed by 50% between 2016 and 2019 – causing more than 200 000 preventable deaths, reveals a joint CDC and WHO report published in 2020. This after cases had been steadily declining between 2000 and 2016. 

What’s to blame for the surge? 

Countries’ failure to vaccinate, the authors write, causing gaps in immunity in young children and adults. 

In the United States, a resurgence of measles nearly robbed the country of its elimination status. The country reported 1 282 cases of measles in 2019, a nearly thirty-year high, according to CDC surveillance data

The national vaccination rate for measles in the US is good on average – 94,7% – in line with 93% to 95% coverage needed for herd immunity, according to mathematical modelling presented to the World Health Organisation.  

But outbreaks can still occur in individual communities where there are pockets of people who are unvaccinated, explain the authors in a Lancet Infectious Diseases study

A 2014 measles outbreak at Disneyland in California, for example, was a direct result of low vaccination coverage, which was between 50% and 86% in that year, according to the state’s school reporting data. 

A study published in the Journal of the American Medical Association Paediatrics found that even a 5% drop in MMR vaccine coverage could result in measles cases tripling for children between the ages of 2 and 11 each year. 

Across the pond, the United Kingdom lost its measles free status in 2019. The government health agency Public Health England recorded 991 cases of measles in 2018, triple the number recorded in 2017.

Why don’t people vaccinate? 

In 2020, researchers found the biggest reason for vaccine hesitancy in Europe was parents’ fear that jabs could be harmful to their children. The research was published in the Journal of Epidemiology and Global Health.

Such beliefs can be traced back to a 1998 study published in The Lancet that falsely claimed that the MMR vaccine could cause autism in children. The research was fundamentally flawed and the journal retracted it in 2010, but the myth has caused ongoing damage to global efforts to eradicate the disease.

Locally, an increasing number of South Africans buy into unfounded theories that vaccines are dangerous to use, shows a 2015 study published in the South African Medical Journal.  

The research looked into the prevalence of online anti-vaccination lobbying from South Africa over three years. More than half of local websites included in the study, which claimed that vaccines are ineffective or unsafe, were authored by parents.

There are 18 states in the US that allow parents to opt out of vaccinating their children for non-medical reasons including religious or ”philosophical reasons” (such as the unfounded belief that vaccines cause autism, for example).  

Research published in the journal PLoS Medicine found an increasing number of parents in 12 of those 18 states were not having their children vaccinated against measles. And, they found that the number of non-medical exemptions in a state is strongly linked to the occurrence of measles outbreaks. 

What can we learn from measles vaccination programmes? 

Making vaccines available doesn’t necessarily mean people will take — or trust — them, Gavi, the Vaccine Alliance’s strategy to eradicate measles and rubella, warns. Vaccine roll-out strategies therefore need to include well-designed communication plans to make sure communities know why measles outbreaks are a threat, and why vaccines can help keep their loved ones safe. In short, people need to trust the vaccine. 

The WHO says the most successful communication strategies to change vaccine-hesitant people’s minds about immunisation are programmes in which leaders from government or churches engage with their communities to promote vaccination in language that is easy to understand and that takes cultural norms into account.

“Familiarity and trust with the messenger” strongly influences the success of such campaigns.  Some countries have had success with making measles vaccines mandatory.

In France, children are, for instance, not able to attend a state school without a measles vaccination certificate and the World Health Organisation also says mandatory vaccination is an effective way to increase immunisation rates

But compulsory vaccinations, some experts say, can also increase vaccine resistance and conspiracy theories. 

In South Africa, all forms of vaccination, including Covid vaccinations, are voluntary. Which interventions are the most successful? Those with the most human contact, where leaders talk directly to communities, says the WHO.

Strategies that only “talk” to people from a distance, for instance posters, media releases and radio announcements, are of little benefit,  the WHO found. Rather, people change their minds when there is dialogue and personal contact.  

This story was produced by the Bhekisisa Centre for Health Journalism. Sign up for the newsletter.

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