Raising concerns about growing health inequalities after the COVID-19 pandemic, global health experts have called to improve healthcare capabilities to respond to established infectious diseases like malaria, measles and tuberculosis while also responding to emerging threats.

According to Anthony S. Fauci, the outgoing director of the National Institute of Allergy and Infectious Diseases (NIAID) in the US, COVID-19 is "the loudest wake-up call in more than a century to our vulnerability to outbreaks of emerging infectious diseases".

In a perspective in The New England Journal of Medicine, Fauci said that the emergence of HIV/AIDS in 1981 led to a sharp increase in interest in infectious diseases among people entering the field of medicine.

Since then, infectious disease specialists have faced numerous medical challenges, including the 2009 H1N1 influenza pandemic, Ebola, Zika, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and COVID-19.

"Once considered a potentially static field of medicine, the discipline of studying infectious diseases has proven to be dynamic as emerging and reemerging infectious diseases present continuous challenges," Fauci wrote.

The latest study by the Queen Mary University of London, published in BMJ Open, found that only 75 per cent of children are receiving the first dose of the MMR vaccine on time, compared to the 95 per cent needed to prevent outbreaks of measles, a highly infectious disease.

Measles is of particular concern because it can cause serious complications for some children, including pneumonia or brain swelling, and it is very infectious -- one person with measles typically infects 12-18 other people in an unprotected population.

The World Health Organisation (WHO) recommends that 95 per cent of children receive both doses of their MMR vaccine to avoid a measles outbreak.

"There is an urgent need to ensure all families have equitable, timely access to routine immunisations, regardless of their circumstances. The risk of an unprotected child catching measles is much higher if they are surrounded by other unprotected children, so we are particularly concerned about these increasing 'hotspots' where timely vaccination is below 60 per cent," said Carol Dezateux, Professor of Clinical Epidemiology and Health Data Science at the Queen Mary University of London.

In India, more than 10,000 laboratory-confirmed cases of measles and 40 deaths due to it among children have been reported to date. Maharashtra reported 3,075 cases and 13 deaths, followed by Jharkhand with 2,683 cases and eight deaths.

Meanwhile, a new study led by faculty at the University of Georgia, published in The Lancet Global Health, said that current vaccination strategies are unlikely to eliminate measles.

Despite marked reductions in the number of new measles and rubella cases worldwide, gaps remain between current levels of transmission and disease elimination.

"Measles is one of the most contagious respiratory infections out there, and it moves quickly, so it's hard to control," said lead author Amy Winter, an assistant professor of epidemiology and biostatistics at UGA's College of Public Health.

It's critical to remain vigilant to surveil for rubella and measles cases and rapidly respond to potential outbreaks even after elimination is achieved.

"We have a globally connected world, so there's this constant pressure of importations of the viruses in places where it's already eliminated," she said. "That's why keeping vaccination coverage high and continuing to improve surveillance for these diseases is important."