Measles cases have been skyrocketing in recent years around the world. The lack of confidence in vaccines and the Covid-19 pandemic have a lot to do with it. The consequences are serious.
We often tend to think of measles as an embarrassing childhood disease with those red patches that gradually cover the whole body, but harmless and has been overcome. Wrongly: it is a serious viral disease, very contagious (an infected person can infect 15 to 20 others; it is contagious before the rash and five days after on average) and easily transmitted. It can be contracted at any age and can lead to serious complications – sometimes fatal.
This is why we should be concerned that between 2016 and 2019, the number of reported measles cases worldwide increased by 556% to 869,770, the highest number since 1996. Over 140,000 people died from it in 2018, mostly children under the age of 5. A tragedy all the more disheartening in that it could have been largely avoided.
What’s more, between 2018 and 2020, a measles outbreak in the Democratic Republic of the Congo infected more than 460,000 children and caused nearly 8,000 deaths.
The rise continues and the UN has already warned that, over the first two months of 2022, measles cases will increase by 79% worldwide. Between September 2021 and February 2022, Somalia reported 5,760 measles cases, Nigeria 5,613 cases, India 4,178 cases, Ethiopia 1,979 cases, Pakistan 1,861 cases and so on. One could thus continue to enumerate the countries affected by thousands of infections. This is very bad news.
We thought it was eradicated… but it is coming back
Some Western countries are also following this trend. In 2000, the United States of America thus declared measles eliminated from its territory. However, in 2019, nearly 1,300 measles cases were reported in 31 states across the country, the highest number since 1992. What’s going on?
Analysis of the 2018-2019 measles epidemic in New York, the largest in the country for almost three decades, has identified the factors behind this unexpected magnitude: in this case it was late vaccination of young children combined with increased contact between them…probably at “measles parties” organized to deliberately infect children.
Infections have occurred mainly in toddlers aged 1 to 4 years and infants less than one year old. To contain the outbreak, the New York City Department of Health and Mental Hygiene launched extensive vaccination campaigns and ordered mandatory vaccination of everyone living, working, or attending school within the codes. post office concerned.
As a result of this voluntary policy, between October 2018 and July 2019, more than 32,000 people under the age of 19 were vaccinated against measles, mumps and rubella (MMR). And the epidemic has diminished.
Further analysis suggests that without the vaccination campaigns, the outbreak could have infected between 6,500 and 8,100 people compared to the actual 649 cases.
Let’s make it clear: these “measles parties” are a senseless and dangerous practice, which must be eradicated.
The French do not trust vaccines
Before the introduction of the measles vaccine in 1963 and the generalization of vaccination, major worldwide epidemics occurred approximately every 2 to 3 years and caused some 2.6 million deaths per year. Between 2000 and 2018, vaccination averted around 23.2 million deaths.
Despite the evidence, a global survey of 67 countries published in 2016 found confidence in vaccine safety in France to be the lowest in the world. And this increases the risk of infectious epidemics, including measles. Perhaps because of this problem, measles cases in France amounted to 2,637 in 2019. [Between 2008 and 2020, of the more than 30,000 cases declared in France, 1,700 people developed severe 42 a neurological complication (39 encephalitis, 1 myelitis, 2 Guillain-Barré) and 26 died, Ed.]
Fortunately, according to 2020 data, confidence in the value and safety of the measles vaccine has increased markedly in many countries. In general, in the European Union, it is considered high.
In Spain, confidence in vaccines is good. The MMR (measles, rubella and mumps) vaccination program was introduced in 1981. The MMR vaccine contains live attenuated measles and mumps viruses prepared in chicken embryo cell cultures. It also contains live attenuated rubella virus prepared in human lung cells (specifically fibroblasts).
Its consistently high vaccination coverage allowed Spain to be declared free of endemic measles transmission in 2014. In 2017, the World Health Organization for Europe declared measles eliminated from the country after the absence of endemic transmission for a period of at least 36 months. Since then, reported measles cases and outbreaks have always been imported or import-related.
Measles virus diversity
WHO recognizes 24 genotypes of measles virus (A, B1, B2, B3, C1, C2, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, E, F, G1, G2, G3, H1 and H2), divided into eight clades (AH). Despite this heterogeneity, all are considered to belong to one major type. Most of the strains used in the development of vaccines are derived from the Edmonston strain (genotype A) isolated in 1954 and are effective against all the others.
Currently, only three of these 24 known genotypes are responsible for epidemics worldwide: the H1 genotype, which is endemic in China; B3, mainly present in African countries (where it originates); and the D8 genotype, which appeared in Asia in the 1980s but is now widespread worldwide.
The D8 and B3 genotypes are responsible for the epidemics that have occurred in recent years in Europe, Asia and North America.
The impact of the Covid-19 pandemic
Unfortunately, the measures taken to control one epidemic can have harmful consequences on another. Thus, the Covid-19 pandemic has had a serious impact on immunization programs and measles surveillance systems in many countries.
In March 2020, the World Health Organization (WHO) issued guidelines stating that mass vaccination campaigns should be suspended in order to maintain physical distancing and minimize transmission of the coronavirus.
However, the interruption of vaccination services, even for short periods, had the effect of increasing the number of susceptible people and communities where protective coverage is less than 95% (the rate to be reached to obtain herd immunity against this virus). The result has been a global increase in measles outbreaks.
It is estimated that a 15% reduction in routine measles vaccinations could increase child deaths by almost 250,000 in the poorest countries. The suspension of these mass vaccination campaigns is particularly pernicious in countries caught up in conflict. Among other things because the malnutrition of children and mothers is then more frequent, which increases mortality in the event of infection.
A disease that is not without danger
Although vaccination and good medical care can reduce the likelihood of serious complications, measles-related deaths and hospitalizations due to complications occur even in developed and industrialized European countries. [Complications occur in 30% of cases and are more severe in immunocompromised people, infants and adults over the age of twenty. They range from otitis and diarrhea to damage to the liver, kidneys, lungs or eyes. In one out of a thousand cases, neurological complications are observed, encephalitis for example, Editor’s note.]
This is why the WHO recommends the vaccination of susceptible children and adults for whom it is not contraindicated.
Currently, there is no doubt that the measles vaccine is safe, effective and inexpensive. It should therefore be included in all national immunization programs.