Virus World

Urgent measures are needed now to stop further spread, the World Health Organization says. Health chiefs are warning that cases are still rising and "urgent measures" are needed to prevent further spread. Some 42,200 people were infected in 2023, compared to 941 during the whole of 2022. The WHO believes this is a result of fewer children being vaccinated against the disease during the Covid pandemic. In the UK, health officials said last week that an outbreak of highly contagious measles in the West Midlands could spread rapidly to other towns and cities with low vaccination rates. More than 3.4 million children under the age of 16 are unprotected and at risk of becoming ill from the disease, according to NHS England. Millions of parents and carers are being contacted and urged to make an appointment to ensure their children are fully vaccinated against measles. The measles, mumps and rubella (MMR) vaccine is given in two doses - the first around the age of one and the second when a child is about three years and four months old. The vaccine is very effective at protecting against measles, but only 85% of children starting primary school in the UK have had both jabs.

Speaking about the situation in Europe, Dr Hans Kluge, regional director at the WHO, said: "We have seen, in the region, not only a 30-fold increase in measles cases, but also nearly 21,000 hospitalisations and five measles-related deaths. This is concerning. "Vaccination is the only way to protect children from this potentially dangerous disease." Measles can be a serious illness at any age. It often starts with a high fever and a rash, which normally clears up within 10 days - but complications can include pneumonia, meningitis, blindness and seizures. Babies who are too young to have been given their first dose of vaccine, pregnant women and those who have weakened immune systems are most at risk. During pregnancy, measles can lead to stillbirth, miscarriage and a baby being born with a low birth weight. All countries in the European region are being asked to detect and respond to measles outbreaks quickly, alongside giving vaccines to more people. The WHO said measles had affected all age groups last year - young and old alike. Overall, two in five cases were in children aged 1-4, and one in five cases were in adults aged 20 and above. Between January and October 2023, 20,918 people across Europe were admitted to hospital with measles. In two countries, five measles-related deaths were also reported.

Pandemic effect

Vaccination rates for the first dose of the MMR vaccine, which protects against measles, slipped from 96% in 2019 to 93% in 2022 across Europe. Uptake of the second dose fell from 92% to 91% over the same period. That seemingly small drop in vaccination take-up means more than 1.8 million children in Europe missed a measles vaccination during those two years. "The Covid-19 pandemic significantly impacted immunisation system performance in this period, resulting in an accumulation of un-[vaccinated] and under-vaccinated children," the WHO reported. With international travel booming once again, and social-distancing measures removed, the risk of measles spreading across borders and within communities is much greater - especially within under-vaccinated populations, it said. Even countries that have achieved measles elimination status are at risk of large outbreaks, the WHO warned. It says that 95% of children need to be vaccinated with two doses against measles in all communities to prevent the spread of the highly-contagious disease.

The flare-up of one of the world’s most infectious diseases has taken hold among church congregations that have rejected vaccinations.  A measles outbreak in Zimbabwe has now killed nearly 700 children, in a rapidly accelerating and “deeply concerning” flare-up of the highly contagious disease.  Health officials told the Telegraph they were alarmed by both the speed of the spread and the high fatality rate of the outbreak, which has seen the recent death toll jump by dozens each day. The flare-up of one of the world’s most infectious diseases has taken hold among church congregations that have rejected vaccinations for religious reasons. Deaths had reached 698 by September 4, according to the nation’s health ministry, up from less than a quarter of that a fortnight earlier. Officials reported that 37 children died on September 1 alone.  The outbreak is thought to be the worst for some time in the southern African nation of 15 million. The last outbreak 11 years ago was far less severe, health sources told the Telegraph. Unicef said that in the worst affected eastern province of Manicaland, nearly one-in-10 of those getting the disease were dying. That rate is higher than in other recent African outbreaks. The UN body said it was “deeply concerned with the numbers of cases and deaths among children due to a measles outbreak in Zimbabwe”. Cases first emerged in April and the virus has since spread quickly among congregations of Zimbabwe’s Apostolic churches, who have long rejected vaccinations and modern medicine.

Faith healers and anti-vaxxers

Dr Johannes Marisa, the president of the Medical and Dental Private Practitioners of Zimbabwe Association, told The Associated Press that the government may need to force children to be vaccinated. He said: “Because of the resistance, education may not be enough so the government should also consider using coercive measures to ensure that no one is allowed to refuse vaccination for their children.” He urged the government to “consider enacting legislation that makes vaccination against killer diseases such as measles mandatory”.  Zimbabwe’s Cabinet has already invoked a law used to respond to disasters to deal with the outbreak and has launched a mass vaccination campaign, which will target two million children under five years. Nationwide, the vaccination rate was around 85 per cent in 2020, having fallen back on previous years when it at times touched 95 per cent.  The country’s Apostolic churches or sects are thought to be followed by around one-in-five of the population. Their teachings regularly include a potent mix of opposition towards Western medicine and belief in faith healing and prayer, meaning the congregations have become a stronghold of anti-vaccination sentiment.  As the outbreak has worsened and pressure has mounted, some church leaders have in recent weeks appeared to change their stance and called on followers to get their children vaccinated. The virus causes fever, coughing and a tell-tale rash, but in some cases it causes complications that can be fatal. Complications include blindness, brain swelling, severe diarrhoea and dehydration, ear infections, or severe respiratory infections such as pneumonia. It is one of the world’s most contagious diseases, with a reproduction rate as high as 18 – compared to an R rate of between 2 and 3 for the original strain of Covid.  Before mass vaccinations began in the 1960s, the disease flared up in occasional epidemics, killing an estimated 2.6m children each year. More than 140,000 people died from measles in 2018 – mostly children under the age of five years, despite the availability of a safe and effective vaccine, according to the World Health Organization. The virus is so contagious that more than 90 per cent of the population needs to be immunised to prevent outbreaks.

Some of the most fragile health systems in the world can teach us ways to respond to public health threats early and effectively. Stephanie Nolen, a global health reporter, has reported on pandemics around the world, including H.I.V., cholera and yellow fever.

Souilmi et al. find that strong genetic adaptation occurred in human East Asian populations, at multiple genes that interact with coronaviruses, including SARS-CoV-2. The adaptation
started 25,000 years ago, and functional analysis of the adapting genes supports the occurrence of a corona- or related virus epidemic around that time in East Asia.

Highlights

Summary The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has emphasized the vulnerability of human populations to novel viral pressures, despite the vast array of epidemiological and biomedical tools now available. Notably, modern human genomes contain evolutionary information tracing back tens of thousands of years, which may help identify the viruses that have impacted our ancestors—pointing to which viruses have future pandemic potential. Here, we apply evolutionary analyses to human genomic datasets to recover selection events involving tens of human genes that interact with coronaviruses, including SARS-CoV-2, that likely started more than 20,000 years ago. These adaptive events were limited to the population ancestral to East Asian populations. Multiple lines of functional evidence support an ancient viral selective pressure, and East Asia is the geographical origin of several modern coronavirus epidemics. An arms race with an ancient coronavirus, or with a different virus that happened to use similar interactions as coronaviruses with human hosts, may thus have taken place in ancestral East Asian populations. By learning more about our ancient viral foes, our study highlights the promise of evolutionary information to better predict the pandemics of the future. Importantly, adaptation to ancient viral epidemics in specific human populations does not necessarily imply any difference in genetic susceptibility between different human populations, and the current evidence points toward an overwhelming impact of socioeconomic factors in the case of coronavirus disease 2019 (COVID-19).

Published in Current Biology (June 24, 2021): https://doi.org/10.1016/j.cub.2021.05.067