The pandemic could have caused the greatest disruption in history in routine immunization programs, putting some 17 million children around the world, in rich and poor countries, at risk of contracting measles, diphtheria, tetanus and whooping cough. according to a study published this Thursday in the scientific journal The Lancet.
Research carried out by US experts estimates that global coverage of the first dose of measles vaccine (MCV1) and that of the third dose of diphtheria, tetanus and pertussis (DTP3) could have fallen below 80 % in 2020.
This is a decline of 7% below the expected levels for both preparations had the pandemic not broken out.
As explained The Lancet In a statement, estimates indicate unrivaled disruptions and coverage in 2020 is likely to drop in some regions to levels not seen in more than a decade.
“Before the pandemic, millions of children around the world were not receiving the usual vaccine doses. Those numbers have dropped dangerously since the pandemic, and coverage in 2020 has dropped to levels not seen in more than a decade. “says Kate Causey, a researcher at the University of Washington School of Medicine and author of the study.
“These diseases could come back in force”
Combined with the disruptions suffered by mass vaccination campaigns in 2020, these drops could increase the risk of future measles outbreaks and deaths, according to the authors of the study, funded by the Bill and Melinda Gates Foundation.
Despite the fact that by December 2020 the monthly doses administered around the world began to touch the expected levels, the continuous transmission of the coronavirus, the emergency posed by the new variants and the focus on immunization against COVID-19 could reverse or stall those positive trends, experts warn.
They underline that if concerted action is not taken, especially as populations become increasingly interrelated, the world will face increased risks of outbreaks of infectious diseases that are preventable with vaccines, such as measles and whooping cough.
“Many healthcare systems around the world continue to come under immense pressure from COVID-19 and are working hard to roll out new vaccination programs, but it is imperative that routine childhood vaccinations, which save the lives of millions of children each year, do not forget it, “says another of the study’s authors, Jonathan Mosser, also of the University of Washington School of Medicine.
“If efforts are not redoubled, these preventable diseases could return strongly,” he warns.
The reasons for the alterations vary: lockdowns have made it difficult for parents to access vaccines, as well as fears of contracting COVID-19; The toilets were referred to other functions related to the coronavirus and there has also been a lack of appropriate protective equipment and problems in the supply chain.
South Asia, the most affected region
Scientists have modeled human movement data captured by tracking mobile phones in 134 countries to generate projections and estimate the disruption of vaccine supply in 100 countries where such data on monthly vaccine administration was not available.
They also created a model of the number of doses expected to be injected in 2020 if the pandemic had not occurred to estimate the number of children who missed their routine doses.
The results indicate that South Asia was the region most affected by this problem, with 3.6 million doses of DTP3 and 2.2 million MCV1 lost due to the pandemic, while in high-income countries the number of minors doses were more than doubled: 1.2 million doses of DTP3 and 1.5 million doses of MCV1.
The alterations were less in sub-Saharan Africa, where coverage fell by 4% – some 900,000 children not vaccinated with DTP3 and 1.1 million minors without MCV1 – they add. However, the authors stress that many countries in this region had lower routine vaccination coverage prior to the pandemic and rely on regular mass vaccination campaigns to prevent outbreaks of diseases such as measles. In these countries, the risk of outbreaks may remain high, even though interruptions to routine services are minor.
The researchers note that their study has significant limitations, including that mobility measures are imperfect indicators of the broader social effects of the pandemic and may not fully represent changes in the application of vaccination in different places and over time. .
They also highlight that changes in country-reported data on administered doses may not correspond to changes in coverage, because they generally exclude doses administered outside of target schedules and supplemental immunization activities, and therefore may not fully grasp recovery vaccination efforts. Finally, they note that they were unable to take into account possible delays in reporting or data quality issues associated with the ongoing pandemic.
23 million children without basic vaccines, according to the WHO
Also this Thursday, the World Health Organization and Unicef have published data that reveal that almost 23 million children in the world did not receive in 2020 one of the most common vaccines, DTP3 (against diphtheria, tetanus and pertussis ).
The agencies warn that the figure represents a great setback: it is the highest since 2009 and is 3.7 million more than in 2019.
“As countries clamor for COVID-19 vaccines, we have backtracked on other vaccinations, leaving children at risk of devastating but preventable diseases,” says WHO Director-General Tedros Adhanom Ghebreyesus.
The 22.7 million children who did not receive DTP3 last year, a sharp increase compared to 19 million in 2019, represents a three-point increase in the percentage of unprotected minors, from around 86% in 2019 to 83% in 2020.
The main factor that explains the decline in immunizations was the pandemic, which paralyzed vaccination services in many countries, or caused many families to avoid taking their children to be vaccinated for fear of catching COVID.
“The world gave priority to the fight against COVID, but if ground is not recovered and essential vaccination programs are not resumed, there is a serious risk of large outbreaks” of other diseases, has warned the director of the Department of Immunization of the WHO, Katherine O’Brien.
“We cannot jump from one health crisis to another, and that will happen if we do not heed the warnings and commit to immunize all the children on the planet,” he highlighted when presenting the figures from a study carried out by the WHO and the Fund. of the United Nations for Children (UNICEF).
Research also shows a decline in measles vaccinations, with the percentage of children who did not receive at least one dose last year rose from 14% to 16%, while 30% did not receive the two necessary doses, far away. of the 95% universal goal needed to prevent outbreaks.
O’Brien also cautions that the number of girls vaccinated against the human papillomavirus has been reduced, an immunization that can help them avoid forms of cervical cancer in adulthood. Around 1.6 million girls missed this vaccine in 2020, up from 13 million in 2019, the Canadian expert explained.
The decline in vaccinations, he stresses, was especially worrying in South Asia, the Middle East and America, the latter continent where immunization programs were also affected by “financial problems, misinformation about vaccines and political instability.” .
The country where the most minors were left unprotected in absolute terms was India, with 3.5 million children who did not receive the DTP3 vaccine, followed by Nigeria (3.1 million) and the Democratic Republic of the Congo (1.5 million).
In Latin America, disruptions in vaccination programs caused by COVID-19 prevented 650,000 children in Brazil and 563,000 in Mexico from being immunized against diphtheria, tetanus and pertussis, according to statistics from WHO and UNICEF.
“Even before the pandemic, there were worrying signs that we were starting to lose ground in the fight to immunize children against preventable childhood diseases, including the widespread measles outbreaks that occurred two years ago,” he warned. UNICEF Executive Director Henrietta Fore. “The pandemic has worsened an already problematic situation. With the equitable distribution of COVID-19 vaccines on everyone’s mind, we must remember that the distribution of vaccines has always been uneven, but it doesn’t have to be.” .